e-use(aq) pathfinder project...whilst ates could offer an opportunity for the effective use and...

E-USE(aq) Pathfinder project

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Table of contents 1 project execution overview ............................................................................................. 6

1.1 Project summary: theme, scope and goals .............................................................. 6

1.2 Project implementation summary ............................................................................ 6

1.2.1 Schedule – summary of project steps schedule (planned vs. actual) ..................... 6

1.2.2 Project costs .......................................................................................................... 7

1.2.3 Outcome overview ................................................................................................. 7

1.2.4 Lessons learnt and recommendations ................................................................... 7

1.3 Project team members ............................................................................................ 7

2 Summary ‘more with soil energy’ (D1.1) ......................................................................... 8

2.1 The research program Meer met bodemenergie ..................................................... 8

2.2 Literature study ....................................................................................................... 8

2.2.1 Settlement ............................................................................................................. 8

2.2.2 Salinization ............................................................................................................ 9

2.2.3 Well clogging ......................................................................................................... 9

2.2.4 Closed loop ATES ................................................................................................. 9

2.3 Effects on water quality and microbiology ...............................................................10

2.4 Modelling hydrological and thermal effects .............................................................11

2.5 High temperature storage systems .........................................................................12

2.6 Interference between ATES ...................................................................................13

2.7 Autonomous temperature rise of the subsurface ....................................................13

2.8 Effects on contaminants and combination with remediation ....................................14

2.9 Area based groundwater management...................................................................15

2.10 ATES in combination with water and energy supply ...............................................16

2.11 Policy recommendations ........................................................................................17

2.12 Meer met bodemenergie reports ............................................................................18

3 Barrier assessment & market potential survey (D1.2&D2.1) ..........................................19

3.1 Methodology...........................................................................................................19

3.1.1 Use of abbreviations & definitions .........................................................................19

3.1.2 Existing literature ..................................................................................................19

3.1.3 Questionnaire .......................................................................................................22

3.2 Results ...................................................................................................................23

3.2.1 Geology, hydrogeological requirements and aquifer quality ..................................23

3.2.2 Legislation ............................................................................................................28

3.2.3 Socio-economic parameters .................................................................................34


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3.2.4 Barrier assessment ...............................................................................................38

3.2.4 Opportunity assessment .......................................................................................41

3.3 Main barrier analysis ..............................................................................................42

4 Linking preconditions to geography (D2.2) ....................................................................45

4.1 Method ...................................................................................................................45

4.2 Results ...................................................................................................................45

4.2.1 ATES Suitability ..............................................................................................45

4.2.2 Heating/cooling demand ..................................................................................46

4.3 Conclusion .............................................................................................................51

4.4 References .............................................................................................................51

5 German test site & pilot design description (D3-A) ........................................................52

5.1 Description of building construction site ..................................................................52

5.2 Soil and groundwater properties of building ground ................................................57

5.2.1 Soil properties .....................................................................................................57

5.2.2 Groundwater characterization .............................................................................57

5.2.3 Permeability ........................................................................................................58

5.3 Geothermal situation and potential .........................................................................58

5.3.1 Temperature conditions of construction ground and groundwater .......................58

5.3.2 Hydraulic and thermal parameters of soil layers as used in the thermal-

hydrological model ............................................................................................................59

5.3.3 Hydrogeological and water management situation and effects ............................59

5.3.4 The proposed geothermal energy use ................................................................60

5.3.5 Energy piles simulation .......................................................................................61

5.3.6 Heat and cold demand ........................................................................................72

5.4 Brief introduction of other possible systems ...........................................................75

5.5 Analysis and evaluation ..........................................................................................76

5.5.1 Potential for ATES ..............................................................................................76

5.5.2 Feasibility (barriers to overcome, boundary conditions) ......................................76

5.5.3 Goals ..................................................................................................................78

5.6 Conclusion .............................................................................................................79

5.7 References .............................................................................................................79

6 Italian test site & pilot design description (D3-B) ............................................................81

6.1 Site characterisation and development plan “ex-Mercato Bestiame” ......................81

6.2 Potential for ATES ..................................................................................................82

6.2.1 Subsurface suitability ............................................................................................82

6.2.2 Legislative suitability .............................................................................................83


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6.2.3 ATES opportunities ...............................................................................................84

6.2.3 Barriers for ATES .................................................................................................84

6.3 Energy demand and supply ....................................................................................85

6.3.1 Heat & cold demand .............................................................................................85

6.3.1 Heat & cold supply ................................................................................................86

6.4 ATES scenario evaluation ......................................................................................92

6.5 Conclusion .............................................................................................................93

7 Spanish test site & pilot design description (D3-C) ........................................................95

7.1 Introduction ............................................................................................................95

7.1.1 Location and facilities ......................................................................................95

7.1.2 Barriers to overcome and goals .......................................................................95

7.1.3 The Spanish partners ......................................................................................96

7.2 Site description .......................................................................................................96

7.2.1 Plan of the surroundings .................................................................................96

7.2.2 Geology and hydrogeological conditions .........................................................97

7.2.3 Energy installations .........................................................................................99

7.3 Feasibility check ................................................................................................... 100

7.3.1 Technical feasibility ....................................................................................... 100

7.3.2 Financial feasibility ........................................................................................ 102

7.3.3 Legal feasibility .............................................................................................. 105

7.4 Conclusion ........................................................................................................... 105

8 Belgian test site & pilot design description (D3-D) ....................................................... 106

8.1 Introduction .......................................................................................................... 106

8.1.1 Location and facilities .................................................................................... 106

8.1.2 Barriers to overcome and goals ..................................................................... 107

8.1.3 The partners in Belgium Case ....................................................................... 107

8.2 Detailed site description ....................................................................................... 107

8.2.1 Geohydrological conditions ........................................................................... 107

8.2.2 Energy demand of the facility ............................................................................. 108

8.3 Feasibility check ................................................................................................... 108

8.3.1 Technical feasibility ....................................................................................... 108

8.3.2 Financial feasibility ........................................................................................ 112

8.3.3 Legal feasibility .............................................................................................. 113

8.4 Conclusion ........................................................................................................... 113

9 Swatex general design description (D3-E) ................................................................... 114


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9.1 Introduction .......................................................................................................... 114

9.2 Description of technology ..................................................................................... 114

9.2.1 Shallow stagnant surface waters ................................................................... 114

9.2.2 Flowing surface water ................................................................................... 115

9.2.3 Deep surface waters ..................................................................................... 115

9.3 Benefits & Bottlenecks ......................................................................................... 116

9.3.1 Compensation for UHI ................................................................................... 116

9.3.2 Adaptation for Climate change ...................................................................... 116

9.3.3 Legislation Water temperature / quality (WFD).......................................... 116

9.3.4 Clogging and bio fouling ................................................................................ 116

9.4 Literature .............................................................................................................. 117

10 Business development (D4) ..................................................................................... 118

10.1 Introduction .......................................................................................................... 118

10.2 Typical technical design for ATES systems .......................................................... 118

10.3 Literature review ................................................................................................... 118

10.4 Business case ATES system ................................................................................ 118

10.5 Economic stimuli .................................................................................................. 120

10.6 Conclusion ........................................................................................................... 121

10.7 Literature .............................................................................................................. 122

11 Publications & meetings (D5) ................................................................................... 123

12 Overall Conclusions ................................................................................................. 127


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1 PROJECT EXECUTION OVERVIEW

1.1 Project summary: theme, scope and goals

Storing thermal energy in aquifers and acquiring heat and / or cold from the extracted

groundwater leads to significant CO2 savings (approximately 60%) for heating and cooling of

buildings. On average, the technology gives a return on investments in about 5-8 years. In

the Netherlands, a huge growth is expected. Recent studies in the Netherlands show that

sustainable multifunctional use of groundwater resources is possible by using innovative

combination technologies. A survey executed as part of this Pathfinder project, showed that

the possible field of application in the EU is even much bigger; but also the technical and

legislative challenges are. For instance, in most European countries, aquifer thermal energy

storage (ATES) is not allowed in the proximity of historical groundwater contaminations,

whilst ATES could offer an opportunity for the effective use and remediation of contaminated

groundwater. E-Use(aq) - Pathfinder and Innovation project - aims to pave the way for a

Europe-wide use of this lucrative form of collecting and using sustainable energy, thus

creating many new business and job opportunities. It does so by exploring new concepts for

Europe, translating developments from the Netherlands to different contexts, and generating

effective publicity for this. Within the Pathfinder project, this resulted in new tailor made

technological concepts, adapted to local environmental, socio-economic and legislative

boundary conditions. In the proposed Innovation project, these concepts will be realized in

pilots in cooperation with local partner consortia that were built in the Pathfinder project.

1.2 Project implementation summary

1.2.1 Schedule – summary of project steps schedule (planned vs. actual)

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Task Description Planned completion Actual

completion in

draft

1.1 State of art summary April 2013 May 2013

1.2 Barrier assessment April 2013 October 2013

2.1 Market potential survey June 2013 October 2103

2.2 Linking preconditions to geography June 2013 February 2014

3.1 Finding test sites and local partners July 2013 Spring 2014

3.2 Conceptual designs August 2013 Fall 2014

4.1 Financial stimulants September 2013 Fall 2014

4.2 Business cases October 2013 Fall 2014

5.1 Publicity December 2013 Fall 2014

5.2 Reaching partners and clients December 2013 Fall 2014

Since some issues considering the proposal had to be tackled first, the project could not start

properly until Summer 2013, which consequently lead to more delay due to the holiday


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period. Subsequently, finding test sites and partners turned out to be more problematical

than expected, so more efforts were necessary.

1.2.2 Project costs

Due to the additional activities described above, project budget was raised slightly by 7.9 %

from € 190.000,- to € 205.000,-.

1.2.3 Outcome overview

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Planned deliverable

Description Accomplished See chapter

D.1.1 Summary ‘Meer met bodemenergie’ Report 2

D.1.2 Barrier assessment Report combined with D.2.1 3

D.2.1 Market potential survey Report combined with D.1.2 3

D.2.2 Linking preconditions to geography Maps 4

D.3.1 Potentials test sites and local partners List in Innovation proposal 5-9

D.3.2 Business partner & authority contacts Agreements in Innovation proposal 5-9

D.3.3 Conceptual designs 5 pilot descriptions 5-9

D.4.1 Economic stimuli & business development Report & Innovation proposal 10

D.4.2 Exemplary business cases Included in reports D.4.1 & D.3.3 5-10

D.5.1 Publications List of publications 11

D.5.2 Meetings with potential partners & clients List of meetings 11

1.2.4 Lessons learnt and recommendations

Socio-economic, legislative and some technological barriers prevent widespread application

of soil energy in Europe so far. But these can be overcome. Prove of attractiveness of ATES

applications, because of its cost-effectiveness and its huge potential impact on reduction of

fossil fuel consumption and greenhouse gas production, will promote the use of this type of

renewable energy. Therefore, we advise to run pilots of innovative ATES-solutions in several

European countries, showing how to overcome barriers. This will enable large-scale

deployments of ATES in Europe.

1.3 Project team members

Deltares, Nanne Hoekstra ([email protected])

Arcadis, Hans Slenders ([email protected])

TU Delft, Frans van de Ven ([email protected])

Wageningen University, Martijn Smit ([email protected])

ASTER ScienzaTecnologiaImpresa, Daniela Sani ([email protected])

AIDICO, Alicia Andreu ([email protected])

Naked Energy, Nick Simmons ([email protected])

Energy Center TU Darmstadt, Esther Berghoff ([email protected])


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2 SUMMARY ‘MORE WITH SOIL ENERGY’ (D1.1)

2.1 The research program Meer met bodemenergie

Meer met bodemenergie was a 2 year research program on the effects of and opportunities

for ATES. The objective of the program was to stimulate the growth of sustainable soil

energy by gaining reliable information on the effects on soil and groundwater and to explore

the potential of combining Aquifer Thermal Energy Systems (ATES) with remediation or other

water and/or energy supply.

The main activities were:

• Literature study on all aspects to define the state of the art knowledge

• Monitoring of effects of ATES on temperature, groundwater quality and microbiology at

7 representative pilot locations

• Monitoring of effects of ATES on contaminants at 2 pilot locations

• Laboratorial tests on the effect of temperature and mixing on groundwater quality

• Modelling of individual systems and multiple systems (hydrological and thermal)

• Presentations for and discussion with policy makers and stakeholders

• 2 PhD-students (4 years)

The research was conducted by 4 partners:

• IF Technology (design and operation of ATES)

• Bioclear (specialist in the field of biological soil or groundwater decontamination)

• Deltares (knowledge institute on soil and water management)

• Wageningen University (university in the field of healthy food and living environment)

The project was financed and supervised by more than 30 participants. These participant

were governmental (municipalities, water board, provinces, national), private companies

(energy companies and water suppliers) and representative organizations (sustainable

energy and agriculture sector).

In this summary, a short overview of the activities and the main conclusions from this

program is presented. For reasons of terseness most conclusions are not elaborated or the

basis for the conclusions are left out. All reports (in Dutch) can be downloaded via the

website of the project: http://www.meermetbodemenergie.nl. At the last chapter a translation

of the report titles is given.

2.2 Literature study

2.2.1 Settlement

There is no reported damage as a result of settlement induced by ATES. But there are a few

systems where the expected settlement was a reason for further monitoring of the ground

level. The measured settlement has not yet been compared to the predictions of settlement.

It is recommended to do this with special attention for high temperature storage systems.


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2.2.2 Salinization

Salinization of groundwater could be induced by ATES when fresh water mixes with deeper

brackish or salt water. The regional process of salinization in polder systems is well known

and this knowledge could be used for predicting salinization at ATES.

The central question regarding salinization at ATES is how much 1 ATES will contribute to

shifts in the salt-gradient of the groundwater. Furthermore, what will be the cumulative effect

of multiple ATES in an area?

The reinjection of water at an ATES will reduce the effect of salinization compared to a

groundwater extraction only. This process is however not yet well researched. The

configuration of a system might have influence on the extent of salinization under certain

geohydrological circumstances, but this has not yet ben researched. Known is that

salinization is irreversible. Once it has occurred, it will not recover within tens of years.

Another more policy related question is how much salinization will be accepted; there are no

norms for salinization. For preventing salinization (reduction of fresh water aquifers), ATES is

not allowed in aquifers with a transition from fresh to brackish water.

2.2.3 Well clogging

According to earlier studies, 5 to 10% of ATES has (had) problems with well clogging. In

most cases the problems can be solved easily. Major problems occur rarely. Well clogging

can occur by four main processes:

• Particle clogging occurs most of the times. Frequent switching between extraction and

infiltration will reduce the problems. Furthermore, preventive maintenance make this

controllable.

• Chemical or biological clogging is most of the times induced by mixing of water with

different water qualities (Iron hydroxides). The ATES design should prevent mixing of

different water qualities.

• Well clogging due to gas can be effectively prevented by keeping the water under

pressure. If this is not possible in shallow aquifers with a high gas pressure, degassing

might be considered.

• Thermal expansion of clay particles do not occur under normal circumstances.

Well clogging might become a problem when combining ATES with remediation, but this is

discussed in the chapter on this topic.

2.2.4 Closed loop ATES

Most research focuses on open ATES, but literature research has been done on specific

aspects of closed loop ATES. These aspects are:

• Perforation of aquitards might induce mixing of water from separated groundwater

layers.

• Leakage of glycol into the soil when a system is damaged

• Interference of not registered closed loop systems with open ATES

• There is no solution for removing the tubes when the system is no longer operational

• Freezing of the soil


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The risks associated with these aspects could be controlled with good policies and good

design and operation practices. New policies have become or will become effective soon.

2.3 Effects on water quality and microbiology

The application of ATES results in changes in the groundwatersystem. ATES influences the

ground water system by changing the temperature and by pumping and injecting ground

water, what leads to mixing of ground water with possibly different ground water qualities.

These changes will have an effect on the chemical and/or (micro)biological composition of

the ground water.

The effects of ATES were measured at 9 pilot locations where different types of ATES is

applied. Based on expected geochemical effects the measurement concentrated on changes

in the chloride concentration (mixing of fresh and brackish water), acidity and redox

gradients. The microbiology is assessed by amount, composition, functional behaviour and

biodiversity of bacteria and archeae in the ground water. Besides these measurements,

laboratorial tests were done to analyse the effects of temperature on the microbiology.

The prevailing assumption for open systems is that the influence of the temperature is the

most important parameter for changing chemica land microbiological composition of the

ground water. At the assessed systems the mixing of ground water appeared to be the most

determining factor is for the changes in the ground water system.

Mixing of water is especially important in the first year and/or when a disbalance in the yearly

water flows occur. Mixing of water with different chloride concentrations and hardness was

most often observed at the pilot locations.

Temperature effects were analyzed both theoretical and based on the measurements at the

pilots. The speed of geochemical and biological reactions increases with a factor 2 to 3 at a

temperature increase of 10 to 20 degrees Celsius. In the warm zones the reaction speed is

higher and in the cold zones lower than in the undisturbed ground water. At ATES systems

with an energy balance the amount of heating and cooling in the subsurface is equal, the net

effect of temperature differences at ATES systems on the reaction speed is small. The

temperature differences at the pilot locations have therefore a small influence on the

geochemical composition of the groundwater.

The theoretical analysis for changing reaction speed for temperatures below 20 degrees

Celsius gives no indication for expecting significant temperature effects on a time scale of 20

years. The expected water quality changes based on theoretical analysis for the chemical

balance of Calcium match the measurements at the location with a high temperature

difference.

The laboratorial tests show no effect on the amount of and the functional behaviour of the

micro-organisms at 18 degrees Celsius. At 30 degrees Celsius there are effects on the

activity of the micro-organisms. At the pilot locations these effects have not been found within

the measurement range for the temperature (between 11 and 35 degrees). The measured

amounts and composition of the bacteria lies within the total natural variance in the Dutch


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subsurface, both within and outside the ATES influence zones. The amount and composition

of the bacteria is primarily dependent on the regional location.

At temperatures higher than 30 degrees (laboratorial tests and at the warmest location: 39

degrees) changes in the composition of the microbiological population have been found. The

functional behaviour of the microbiology remains intact. These effects match the theoretical

expectation. At this temperature range other micro-organismes have a selective advantage.

Apparently, they take over the function of the species that originally had the advantage.

Within the temperature range at the pilot locations (up to 39 degrees) no indication has been

found for increase or decrease of the biodiversity with temperature. This is important for the

resilience of the microbiological system.

At the pilot locations there were no or very low numbers of potentially pathogens of the

Enterobacteroceae group or E. coli bacteria found. This is an indication that there was no

contact with sewage water or introduction of contaminated shallow ground water. Legionella

pneumophila was not found on any pilot location, while Clostridium perfringens was only

found at 1 sample at 1 location at very low numbers. These measurements confirm earlier

observations that Legionella does not survive under ATES conditions and that Clostridium

perfringens does not grow towards risky amounts.

At several locations density driven groundwater flow as a result of temperature differences is

observed. Density driven groundwater flow as a result of chloride concentration differences is

observed at 1 location with also a high temperature difference.

For low temperature ATES systems the mixing of water is the most important factor for

potential changes in the water quality. The extent of the changes is dependent on the

difference between the water quality that are mixed. The acceptability of these changes is

also dependent on the (future) objectives for the use of the groundwater.

2.4 Modelling hydrological and thermal effects

In order to verify the current practice and the ability to model ATES correctly, 3 test sites

were analysed. The measurements at the test site were compared with the model

calculations of the hydrological and thermal zones during the design of the ATES.

The calculated hydrological effects are larger than the effects that were measured in the

field. This is a logical consequence of the current practice to model the effects based on a

worst case approach. In order to gain more insight in the uncertainties, a statistical analysis

(MonteCarlo simulation) could be used in more complex situations. For normal ATES

situations the worst case approach will suffice.

Hydrological effects could be calculated by a steady state or a dynamic model. A steady

state model with the maximum water flows will present worst case effects and might

overestimate slow occurring effects. When the seasonal average water flows are used, the

outcomes may give a good impression of the average effects, but will underestimate the

effects during peaks. At one pilot location a comparison is made between a dynamic and

steady state model. The outcomes of these model were nearly equal.


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The reliability of the estimates of the thermal effects is dependent from the reliability of the

model input. The model input consists of expected usage of the ATES (water flow,

temperature difference and variability over time), properties of the system (number and

location of wells, filter length and filter depth) and properties of the subsurface

(heterogeneity, conductivity).

For density driven water flows, which can occur at systems with infiltration temperatures

above 25 degrees Celsius, a 3 dimensional model is needed. Normal ATES can be

calculated with a 2 dimensional model. Thermal models are based on the assumption of a

homogeneous subsurface, but in measurements of the temperature at some locations,

heterogeneity in hydraulic conductivity is observed. In literature the effects of heterogeneity

on temperature distribution is assessed. The overall conclusion is that this effect mostly does

not significantly affect the efficiency of the ATES, if the distance between the wells is

sufficient to prevent interference between both thermal zones. Much heterogeneity can

influence the efficiency of the ATES negatively. At one pilot location with had a high

temperature storage in the past (terminated 8 years ago), the calculated expected extinction

of the thermal zones is compared to recent measurements. The difference between the

measurements and the calculations was not significant; the thermal model delivered a

reliable prediction.

Another uncertainty in the models is the assumption of energy balance and a continuous

constant water flow. In practice, this is often not the case. A comparison between a model

with the design conditions of 1 pilot location and a model with the registered real life water

and energy flows showed on the long term no big differences. Concluded is that the dynamic

effect of water flows does not lead to significant changes between reality and the model

calculations.

2.5 High temperature storage systems

Residual heat (or solar or geothermal heat) often has higher temperatures (40 to 80 degrees

Celsius) than commonly used at normal ATES (up to 25-30 degrees Celsius). The storage of

higher temperature energy (HTS) prevents energy loss during conversion (heat pumps). But

the storage of higher temperature energy in the subsurface has larger consequences for the

subsurface and the wells. In the Netherlands only 2 systems have been operated in the past

and worldwide there aren’t many of these systems.

The main problems that are observed during pilot projects are:

• Low storage- and/or utilization efficiency (due to density driven groundwater flow)

• Well clogging due to precipitation of carbonates

• Corrosion of materials (requires more expensive but existing materials)

• Legislative barriers (high temperature and no energy balance)

To prevent density driven ground water flow due to the temperature difference, aquifers with

low hydraulic conductivity should be used. This also limits the flow rate of the wells. A good

optimization between these factors should be investigated in the future.


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The groundwater quality is affected by HTS due to precipitation of carbonates, changes in

the composition of the kation exchange complex and the possibility to attract deeper ground

water (with another waterquality) due to density driven groundwater flow. At the pilot

locations with temperatures up to 40 degrees Celsius a significant amount of pathogens is

not found. Based on these measurements and literature knowledge growth of pathogens at

HTS is not expected.

Consolidation of the subsurface can be induced by higher temperatures. In practice the net

effect of consolidation due to HTS is small, but consolidation should be considered at all

systems.

Several types of water treatment for preventing well clogging are available: ion exchange,

addition of hydrochloric acid and inhibitors. Ion exchange has some major disadvantages

(extensive use of salt, labour intensive, clogging risk at wrong doses). Addition of

hydrochloric acid may become problematic in fresh water aquifers. An accompanied lowering

of the acidity will lead to dissolving minerals with harmful elements (Arsenic, Nickel and

Zinc). Inhibitors have to be further researched.

2.6 Interference between ATES

Interference is the phenomenon that multiple ATES influence each other (negatively). In high

ATES density areas the assumption is that interference already occurs or with the expected

growth of the number of systems soon will occur. In the Netherlands the policy principle is

that a newer system may not affect the efficiency of an existing system. But nobody knows

whether the current systems achieve the promised efficiency due to own inefficiencies or

negative impact from their neighbouring systems.

One area with a very high ATES density is in MMB modelled: the city centre of The Hague.

This study has two objectives:

1. Investigate the theoretical efficiency of the systems and determine whether the efficiency

decreases with the installation of more ATES in this area.

2. Investigate cumulative regional effects as a result of small effects per system

Given all assumption in the model (in particular extraction rates and energy balance), the

main conclusion is that there is no large scale negative interference between the systems.

Only a few wells (4 out of 76) have lower efficiencies. There are some indications for positive

interference. Apparently, the current allocation system in the Netherlands still suffice, but this

does not imply that other allocation systems (like master plans) are useless.

The simulations show an effect on the regional ground water heads that extends beyond the

individual influence zones. So there is a cumulative effect on ground water flow. Another

point of concern is the highly dynamic and complex ground water flow between the wells.

2.7 Autonomous temperature rise of the subsurface

The temperature of the subsurface can change as a result of climate change, urbanization

and/or ATES. This literature study and modelling of subsurface temperature are conducted to


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offer a frame of reference for acceptation of a certain amount of heating of the subsurface

due to an energy disbalance of ATES.

The temperature at ground level has already increased with 1,7 degrees Celsius since 1900.

This will lead to a higher subsurface temperature. Urban Heat Island effects have

(additionally) increased the temperature up to 3 degrees Celsius. Predictions of the

temperature rise of the subsurface at ground level in 2040 range between 1 to 7 degrees

Celsius. These effects are noticeable till 150 meter below ground level. Most effect will occur

until 40 meter deep. The ATES systems will not be affected by this temperature increase.

ATES usually increases the temperature of the ground water with 2 to 3 degrees Celsius in

the warm zone. For the highly dense area of Den Haag, the spread out effect of an energy

disbalance of 5%, would be +0,01 degrees Celsius.

Another approach is to utilize the already increased temperature of the subsurface for

heating buildings. The subsurface already absorbs so much energy that the heat demand of

rural areas can be fulfilled (if this energy can be extracted). In urban areas the heat demand

is much larger than the absorption of energy of the subsurface. But the absorption of heat by

the subsurface is still 12 times larger than the extraction of heat by the current ATES.

2.8 Effects on contaminants and combination with remediation

Often, application of ATES is desired in contaminated aquifers. Most important contaminants

in this respect are chlorinated hydrocarbons, which are relatively poorly degradable in

geochemical conditions prevailing in most Dutch aquifers. Also volatile aromatics can be

quite persistent in some aquifers. Since even open ATES systems are closed aboveground

and no relevant deterioration of equipment can be expected from dissolved contaminants,

groundwater contaminants are no fundamental barrier for ATES application. However, ATES

systems have to be designed and situated in such a way – for instance placement of filters

within borders of contaminant plumes and not in LNAPL’s and DNAPL’s – that uncontrolled

contaminant migration is prevented. On the other hand could mixing of reactants (in open

ATES) and increase of groundwater temperature enhance biodegradation. Literature

research shows that in the temperature range allowed by Dutch legislation (below 30 °C)

significant biodegradation enhancement can be expected, while the risk of uncontrolled

migration due to increase of solubility and vaporation is limited. At two pilot sites,

enhancement of biodegradation could not conclusively be determined by field en lab

research, but neither could negative effects be found. At the first site, the ATES system was

not adapted for the presence of groundwater contamination; still ongoing degradation could

be confirmed by elaborate monitoring, including innovative analyses on specific DNA and

stable isotopes. At the second site, a special ATES system was designed for a combination

with groundwater remediation; but the system was only recently taken into operation;

nevertheless geochemical conditions already improved in favour of biodegradation.

In combining ATES with groundwater remediation, an optimum has to be found for main

targets energy yield and remediation results, while minimizing costs and maximizing system

life span. For different situations, varying combination designs are applicable. The simplest is

a recirculation system (without real storage of heat and cold), designed in such a way that


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hydrologic containment can be realized; for instance with infiltration wells situated in the

centre of a ring of extraction wells. When correctly configured, up to about 80 % of

contaminated groundwater can be contained. Complete containment may be possible with

contribution of natural attenuation. Mixing of groundwater may bring the necessary electron

donors, acceptors and nutrients together but could, on the other hand, also sweep away

niches with the right conditions for degradation. Energy yield from a doublet system (with

separate wells for heat and cold storage) will, compared to a recirculation system, be higher

but hydrological containment is more problematical. So, enhancing natural degradation is

more important for contaminant management in this type of systems. Degradation can also

be stimulated. Chitin and vegetable oil were selected as suitable electron donors for

enhancing reductive dechlorination of chlorinated hydrocarbons in ATES systems, since with

these substances filter clogging can be avoided. Most effective is the creation of a reactive

zone, for which a novel triplet design was developed. Another possibility is a combination

with purification aboveground, in a purification plant, pond or swamp (for instance with aid of

a helophyte filter). Since site-use, soil stratification and contaminant situation differ, tailor-

made site-specific designs will always be necessary.

2.9 Area based groundwater management

In many urban and industrial areas the soil and groundwater are contaminated from multiple

sources. In these cases, for many reasons, a site specific approach cannot always result in a

cost-effective solution. A new alternative is to organize the remediation and/or control of

contamination centralized in an area based groundwater management approach (ABGM).

This requires legislative, organizational, financial and technical instruments. Area based

groundwater management can also be applied in areas that are not contaminated, but where

there is a need for proper separation of different subsurface functions.

The utilization of ATES to assist in control and/or remediation of contaminations adds

challenges and chances for implementing area based groundwater management. The way

ABGM is chosen and implemented will differ as much as the underlying objectives and area

specific circumstances.

If a substantial water quality improvement is required, the demands for the soil system and

for the way ATES is implemented are much higher than in case of maintaining current water

quality.

Concluded is that besides of the potential positive effects of interaction between ATES and

contaminations, there can be also negative effects. The faster dissolving of DNAPLs as a

result of increased groundwater dynamics by the ATES, is an example of the potential

negative effects.

In the case of utilization of ATES in (possible) contaminated areas, the interaction between

ATES and the contamination plays an important role. There are two main questions to be

answered before large scale AGBM can be implemented.

1 To what extent do ATES contribute in decomposition of contaminants? Is it realistic to

expect ATES to significantly contribute to an improvement of the groundwater quality?


16

2 To what extent can ATES assist in containing of contaminants? Which combinations

with other subsurface or aboveground functions can be made?

Ad 1.

An important parameter is the natural attenuation capacity of the soil. In most areas where

there are plans for AGBM, there is not enough information about this capacity. The often

mentioned ambition to utilize ATES to increase the attenuation capacity is therefore too

optimistic. At one pilot location with an existing contamination, there was a positive trend in

pollutant concentrations observed, but this needs further monitoring before a final conclusion

can be drawn. Combinations of ATES with remediation techniques could be additionally

used.

Ad 2.

There appear to be good possibilities to contain contaminants or – more in general – reduce

risks of contaminants in an ABGM. At this moment the most secure way to utilize ATES in

containing contaminants is to prevent/reduce the reinjection of used cold or warm water. In

this way a net extraction of groundwater is realized and thus prevention of further spreading

of contaminants. This can only be achieved if there is an aboveground function that can use

this water. The effect of spreading contaminants is less critical in an ABGM approach if there

is natural or stimulated attenuation.

Another relevant aspect is the mixing of contaminated and uncontaminated water by ATES.

This will result in a lower concentration. If the ATES are located downstream of a

contaminated area, the ATES may contribute in lowering the concentration of contaminants.

Downstream of these ATES in the direction of an area border (for the ABGM) the

concentrations may become lower than the risk norms. In this way ATES can contribute in

reducing risks of contaminants.

2.10 ATES in combination with water and energy supply

A literature review has been done to identify innovative applications of ATES in combination

with other purposes like water supply and/or energy supply. In the Netherlands most of these

potential applications with other purposes than energy savings are in the concept stadium.

17 potential combination concepts have been identified, but only 3 are further elaborated.

These concepts are analysed on their technical, organizational, financial and legislative

aspects.

1 Storage of industrial residual heat in mid temperature ATES

The concept is to store industrial heat from a major industrial area and use it for residential

heating in a nearby residential area. Major points of concern are scale size, transport

distance and the production of hot tap water. This concept has a lot of potential in terms of

energy saving because a lot of industrial residual heat is available.

2 ATES and irrigation water supply for green houses

By means of reverse osmosis brackish water can be turned into fresh water and a salt

residue. This salt residue can be injected in another aquifer, together with residual heat. The

advantage is the usage of the wells for multiple purposes. The deterioration of the ground


17

water quality has to be considered against the advantages and the availability of other

sources of fresh water supply.

3 ATES and process water

Buildings with a large cooling demand which use drinking water for cooling towers, could also

be served by an ATES system which also extracts ground water for the cooling towers. This

saves high quality drinking water and is therefore environmental friendly and financial

beneficial. This requires an adjustment of current legislation and show cases to prove the

benefits.

2.11 Policy recommendations

As a part of the research program some policy topics were discussed with policy makers and

stake holders. These recommendations are based on the research conclusions and on the

prevailing opinions of these involved parties.

• Infiltration temperature

The maximum infiltration temperature for normal ATES is limited to 25-30 degrees Celsius.

But there is a market demand for higher temperatures. It is recommended that policy makers

assign areas or aquifers where higher temperatures can be potentially allowed at pilot

locations.

• Open ATES and remediation

There are indications for a positive contribution of ATES to remediation or area based

groundwater management. But there is a need for further monitoring of effects at more

locations to gain more insight in the consequences and preconditions. This requires new

locations where ATES and remediation are combined. Within the boundaries of the new

legislations policy makers should make additional pilot locations for combination concepts

and ABGM possible.

• Energy balance

In order to assure sustainable use of the subsurface, the current legislation demands an

energy balance for ATES. This aspect has not been investigated within the Meer met

bodemenergie program itself. The energy balance is however not an assurance for

preventing and is complex to achieve. Recommended is to re-evaluate this aspect of the

legislation with the underlying objectives in mind.

• Interference between open ATES

A couple of recommendations for policy makers are given. In (expected) high ATES dense

areas additional plans for allocation should be developed. Evaluation of licenses (extraction

rates) for current ATES could be beneficial in order to increase the opportunities for new

systems in an area. Investigate interference in practice, based on hydrological, thermal and

financial aspects. This may contribute to (an area based) definition of the extent of

acceptable interference.


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2.12 Meer met bodemenergie reports

Report 1: Connection with policy – Connection between the research outcomes of

MMB with policy aspects

Report 2: Literature study – Overview of knowledge and research questions regarding

ATES

Reports 3 and 4: Effects on the soil and groundwater – Effects of ATES on

geochemistry and microbiology in practice. Results of monitoring at pilot locations and

laboratorial tests.

Report 5: Modelling systems – Effects of ATES at their surroundings. Modelling of

individual ATES projects

Report 6: High temperature storage – Knowledge overview and monitoringdata of

high temperature storage systems

Report 7: Interference – Effects of ATES on their surroundings. Modelling large scale

application of ATES in urban environments

Report 8: Autonomous temperature rise of the subsurface – Autonomous

development of the temperature of the subsurface

Report 9: Effects on remediation – Effects of ATES on remediation. Results of

monitoring at pilot locations and laboratorial tests

Report 10: Opportunities for combination of ATES with remediation. Overview of

remediation techniques and new concepts with ATES

Report 11: Area based groundwater management –Allocation of ATES in area based

groundwater management. Opportunities and points of concern

Report 12: Combinations with the water chain. New applications for ATES in

combination concepts in the water chain


19

3 BARRIER ASSESSMENT & MARKET POTENTIAL SURVEY (D1.2&D2.1)

3.1 Methodology

Existing literature and a questionnaire have been used to provide the data and information.

At first the existing literature has been studied, and based on that, a questionnaire was put

together to fill the gaps found.

3.1.1 Use of abbreviations & definitions

SGE: Shallow Geothermal Energy (both open and closed systems)

ATES: Aquifer thermal Energy Storage (open systems)

GCHP: Ground Coupled Heat Pumps (closed systems)

For this report the official Dutch definition of ATES and GCHP (as described in the Decree

SGE Systems) is used:

ATES:

“installation that uses the subsurface for the supply of heat and cold for the purpose of

heating and cooling of spaces in buildings, by means of the extraction of groundwater that is

re-infiltrated into the subsurface after use, including the above ground part of the installation”

GCHP:

“installation that uses the subsurface for the supply of heat and cold for the purpose of

heating and cooling of spaces in buildings, by means of a closed circuit of piping in the

subsurface, including the above ground part of the installation”.

3.1.2 Existing literature

Completed projects regarding stimulating ATES and/or GCHP systems in Europe, focusing

on existing barriers have been examined. In general, these projects focus on legislation

issues regarding ATES and/or GCHP systems, market situations and barriers in immature

markets. The following completed projects have been examined to provide the required data:

Ground Reach Project

During the three year period from 2006 to 2008, the 21 project partners identified present

status and future potential of GCHP towards reducing CO2 emissions and primary energy

demand, analyze potential contribution of the technology towards the European Directive on

the Energy Performance of Buildings, compile and evaluate best practice information from all

over EU, define measures to overcome barriers and set up a strategic promotion plan for

long term market penetration, and communicate the merits and benefits of GCHP to key

professional groups through a variety of effective promotion tools, such as the International

conference and exhibition.

The GROUND-REACH project is divided into 7 work packages, the last of which corresponds

to common dissemination activities with other European projects.


20

Work package 1 integrates project management activities. Work package 2 leads to the

evaluation of GCHP potential contribution towards Kyoto targets. Work package 3 is intended

for the presentation of the merits and availability of GCHP through best practice examples.

Work package 4, leads to the evaluation of GCHP potential contribution towards the

implementation of the buildings performance directive. Work package 5, leads to the

identification of the barriers to market penetration of the technology, their removal and the

formulation of a strategic dissemination plan for long term market penetration. Work package

6, leads to the short term (during the contract period) market penetration of GCHP. It

includes establishing the European GCHPs Committee as promotion coordinating agent (the

committee met for the first time in March 2007 in Frankfurt, Germany), preparation of

promotional material (GROUND-REACH internet pages, brochures and posters, promotional

text, onscreen presentations), press releases to 7,500,000 recipients, e-mail campaign and

e-questionnaire survey to 3,600 recipients. Work package 7 aims in fulfilling the objectives

for common dissemination tasks, according to Commission requirements.

One of the conclusions from the December 2006 report is:

“The legislative framework is very different around Europe, and in some cases it represents

a real barrier to the geothermal energy use.”

REGEOCITIES project (www.regeocities.eu)

REGEOCITIES project is focused on the achievement of the National Renewable Energy

Action Plans (NREAP) geothermal targets 2020 marked by countries with ambitious

objectives regarding ATES systems by means of the removal and clarification of the non-

technical administrative/ regulatory barriers at local and regional level.

The Objectives are to:

Overcome barriers related to regulation of geothermal resources and administrative

procedures.

Transferring of best practices from mature to juvenile regions

Document with recommendations to develop a common pre-normative framework

Engagement of local administration for implementing project results

Development of a training program focused on the target groups (administrative

personnel from the cities and regions)

Achievement of the smart-cities concept within SGE systems


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Figure 3.3 Target countries REGEOCITIES project

GEO.POWER project (www.geopower-i4c.eu)

GEO.POWER project is part funded by the Interreg IVC Programme. The Interregional

Cooperation Programme INTERREG IVC, financed by the European Union's Regional

Development Fund, helps Regions of Europe work together to share experience and good

practice in the areas of innovation, the knowledge economy, the environment and risk

prevention.

The general objective of GEO.POWER project, 2 years long, is the exchange of best

practices related to ATES systems and - after a technical and cost/benefit assessment to

evaluate the potential of reproducibility - to prepare the ground to the transfer of some of the

selected best practices within the Mainstreaming Programmes of the regions participating

into the project during the current programming period 2007-13, as well as in the future

regional framework instruments.

The main outcomes of the project are the development of one action plan per each involved

region that provides an organized set of legal/regulatory, economical and technical /

technical and best-technological proposals that-through the inclusion into the regional

operation programmes, address long-term investments strategy for GCHP application at

wide scale. The partnership, coordinated by the Province of Ferrara (Italy) is composed by

Ministries, Regions, Local Authorities, Universities and R&D agencies of 9 countries

(Bulgaria, Hungary, Greece, Italy, Sweden, Estonia, UK, Belgium and Slovenia) that are

dealing-at different level-with the attainment of European policy objectives in relation to

20/20/20 Kyoto targets and the EU Building Performance Directive. The partnership benefits

of a strong technical background, as it capitalizes experiences coming from the major EU

projects in the field of low enthalpy geothermal and technological applications, like Ground-

Reach, GROUNDHIT, Ground-Med and LOW-BIN. On the basis of a pool of best practices

on GCHP application developed in urban, rural and industrial sector, all partners and local


22

delegation of experts & stakeholders go through an evaluation of the best practices

reproducibility potential in each recipients region, according to technical, economical and

environmental parameters, in order to design the optimum performance conditions for GCHP

systems and the capacity to fit with the territorial context. The consequent preparation of the

action plans and its inclusion into the Regional Operational Programmes cold represent a

milestone for the future introduction of massive GCHP investments in the concerned regions.

A strong communication strategy aims at increasing awareness, improving knowledge and

better understanding of the GCHP merit and benefits and push investments towards such

green-economy.

3.1.3 Questionnaire

A questionnaire has been conducted within the project E-USE project. Survey methods

included both written questionnaires and communication by email and telephone interviews

with selected partners in the project. This questionnaire is used for providing data and

information for the following sub goals of the work packages 1 and 2:

Barrier assessment Identification of present day barriers for wide-scale market introduction in European

countries. These barriers can be technical, geological or socio-economic and also legislative.

For each country a local partner will perform the assessment, whereas the lead partner will

collate the results. In this Task a difference is made between the technical and financial

applicability of the technology and the policy barriers in the participating Member States.

Market potential assessment

Identification of hydrogeological requirements, aquifer quality, urban and rural planning

consequences for introduction of ATES, including possible innovative combination systems

with SWATEX and other heat and cold sources, and economical and financial developments,

regarding energy use in the partner countries.

Linking preconditions to geography (see also chapter 4) Adding the geographical dimension to both ATES and possible combination systems to

increase applicability of thermal energy from soil, groundwater and surface water.

The questionnaire includes the following subjects:

Geology, hydrogeological requirements and aquifer quality

Legislation

Socio-economic parameters

Barriers and opportunities


23

Questionnaire respondents

The following partners have filled out the questionnaire for the corresponding countries:

KIC Partners Role in project and competences Country

Deltares Project lead, organizational and technological input on all

activities

Netherlands

ARCADIS Development and design of a wide range of innovative ATES-combinations, intermediary for test sites in Belgium

Belgium and UK

Technical

University Delft

Expertise on urban surface water thermal energy collection

systems

Netherlands

ASTER Scienza

Tecnologia Impresa Development of business models and financial incentives, spin-off creation, intermediary for test sites in Italy

Italy

Instituto

Tecnológico de la

Construcción

(AIDICO)

Development and design of innovative combinations of

ATES with closed loop soil energy systems, intermediary

for test sites in Spain

Spain

Energy Center TU Darmstad

Development, design and integration of ATES in the

existing habitat including business models, intermediary for

test sites in Germany

Germany

The required data and information that was required to fill in this questionnaire has been

obtained by using various sources. These sources varied between existing literature, finished

projects and expert interviews.

3.2 Results

3.2.1 Geology, hydrogeological requirements and aquifer quality

Below, the results are summarized per country.

Germany

In general the geological conditions are favorable for ATES systems. In figure 3.1 the

geological conditions are shown (dark blue is very favorable, white is unfavorable):


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Figure 3.1: Geological conditions Germany

According to the Umweltbundesamt (German Federal Environmental Agency) there are

14.209 contaminated areas and 314.347 suspected contaminated areas in Germany.

However this data has to be used with care as there is no obligation of the states to assess

contaminated surfaces.

Well known obstacles are the existing water protection zones. About 12 % of Germany’s

surface is covered with reserved areas that exclude the use of geothermal technologies. In

future, possible conflicts could occur with areas reserved for CCS1.

Another competing usage with geothermal technologies for aquifers can be the deep

injection of contaminated waters from mining activities. Or in future possible storages for

CO2.

The Netherlands

Geological conditions in the Netherlands are very favourable for ATES systems. For 95% of

the ground surface, ATES systems can be implemented. Also in the Netherlands existing

water protection zones are known obstacles since ATES systems are prohibited in these

areas.

In figure 3.2 the geological conditions for ATES systems are shown (Blue is very favorable,

brown is not favorable).


25

Figure 3.2 Geological conditions The Netherlands

Belgium

In Belgium the geological conditions are less favorable for ATES systems, compared to the

Netherlands and Germany as is shown in figure 3.3:


26

Figure 3.3 Updated suitability map for GWE systems in Flanders

Also in Belgium existing water protection zones are known obstacles.

Italy

For Italy, the focus of the inventory was on Emilia-Romagna

(Northern Italy, figure 3.4). Aquifers within 200 m below

ground level are present in almost half of the region, this

amounts to –roughly- 11.000 km2, their overall thickness

reaches about 600 m. The most transmissive aquifers, and

therefore those more suitable for ATES, are those of the

Appenninic alluvial fans, but these are used for drinking

water purposes. It can be concluded that the geological

conditions are not favourable for ATES systems and that

existing water protection zones are severe known obstacles.

Figure 3.4 Emilia-Romagna,

Northern Italy

Spain In Spain, the coastal area has shallow aquifers, less than 200 m deep. The surface Spain is

around of the 505.992 km2, and an average elevation of 650 meters, it’s one of the most

mountainous countries in Europe. The area occupied by aquifers in Spain is estimated at

about 413.075 km2, this is about 82 % of the surface of Spain.


27

In Spain there are 126 wetlands that are connected with groundwater. There are 1.102

superficial reservoirs and 442 aquifers. The area occupied by aquifers is around of 200.000

km2; this means 40 % of the Spanish area. There are 59 coastal aquifers of the 442 Spanish

aquifers, which area estimated is 16.891 Km2.

UK

The principal aquifers of the UK are found in the lowlands of England. The most important

are the Chalk, the Permo-Triassic sandstones, the Jurassic limestones and the Lower

Greensand. They occur within the section of the geological sequence referred to as the

Younger Cover, which ranges in age from the Permian to the Quaternary.

Unlike much of the rest of the works, alluvial sands and gravels are not major aquifer source

in the UK, although wells and borehole are sited in these deposits in many parts of the UK

and supply individual needs.

As the map in figure 3.5 shows, the main centres of the principal aquifers are The London

Basin (where the London Chalk Aquifer can be found shown in green) and the midlands

where the Sandstone Aquifers can be found (shown in orange). Data obtained from the

British Geological Survey and Environment Agency gives the following transmissivity data in

m2/day:

On this basis, the principal aquifers of the UK would fall into the suitable category for thermal

energy storage.

However, it is noted that there are parts of the

UK’s principal aquifer system where

transmissivities over 1,000m2/day can be found.

For example the total range for the UK’s

Sandstone aquifer is 0.9 to 5,200m2/day and the

75th centile for the Chalk aquifer in parts of

the Chilterns, Kennet Valley and North Downs is

between 1,500 and 2,100m2/day. This would put

these localities in the very suitable category for

thermal energy storage. However, the percentage

of these areas compared to the total principal

aquifer system is likely to be limited (in the order of

20%).

Figure 3.5 Principal aquifers UK


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3.2.2 Legislation

General

For detailed legislation information per country, the country reports from the

regeocitiesproject can be found at: http://regeocities.eu/results/.

There are significant differences between the various countries regarding legislation for SGE

systems. In general, permits are required for ATES systems and often also for GCHP

systems. The administrative approval can take up a lot of time as a function of the size of the

ATES system.

In most countries regulations are often not adapted to the use of ATES systems and long

and unclear procedures occur due to a lack of precision in the conditions required for drilling

operations and for the use of the geothermal resources.

Germany

For Germany, compared to the description in the 2006 inventory (groundreach project) the

legal framework in Germany for SGE systems has not been changed. Moreover there is no

indication that the legal framework in Germany for ATES systems will be changed in the

nearer future either.

For any intrusion into the underground (drilling or digging), permission is required from a

certain depth on. This depth limit can be given in meters within certain protected areas, e.g. 2

m or 5 m in some spa protection areas (Heilquellenschutzgebiete). A general rule is that

permission is needed whenever the intrusion into the underground reaches the groundwater

level. This is stated on the federal level in the Water Household Act (WHG, status 2009), e.g.

in WHG § 49. There are some exceptions, listed in WHG § 46, like private garden wells,

agricultural wells, etc. In any other case a license (Erlaubnis as to WHG § 8) from the

relevant water authorities is required, and this is the case also for both open and closed loop

geothermal systems. The license is applied for with the lower

water authorities (on district or city level), the application typically being prepared by the

driller and signed by the owner of the site.

For boreholes penetrating more than 100 m into the underground (100 m of drilling length,

not necessarily vertical depth), the application has to go to the mining authorities as to

BBergG § 127, and the mining authorities will carry out the licensing process including the

water authorities into the procedures.

Another requirement is that all “drillings driven by mechanical power” have to be reported to

the Geological Survey of the respective state. This is stipulated in the Lagerstättengesetz

(LagerstG), which dates already from 1934, but has been updated in 1974. LagerstG § 4

states the reporting duty, § 3 requires geophysical measurements to be reported to the

surveys.

Ownership of heat & cold

Generally, geothermal energy including shallow geothermal energy is subject to the

regulations of the Federal Mining Law, hence the right to use the energy available from the

http://regeocities.eu/results/


29

soil space beneath a particular property does not belong to the property owner. But, in the

case that geothermal energy is only used for the energy supply in context with the use of the

own property and, the geothermal facility does not exceed a depth of 100 m, the exploitation

of the geothermal energy can be regulated by a permit process with in the Water Household

Act (WHG). A geothermal facility might have influence on the neighbor’s property when the

distance between the borehole heat exchangers is too small. It is important to ensure that the

installation and operation of a geothermal system on the neighboring property remains

possible at all times. According to the VDI 4640 part 1 the minimum distance to the

neighboring property should be chosen as large as possible.

Balancing of heat & cold

There are no strict regulations regarding balancing heat & cold. Especially in areas of high

population density the interference of geothermal constructions has to be analyzed carefully

because the temperature of the groundwater in these areas is mostly strikingly increased as

a result of anthropogenic influences.

Netherlands In the Netherlands, both the national legislation and the legislation in the provinces are

adapted to the ATES and GCHP systems. Using aquifers for geothermal resources is taken

into account and permit conditions are described and clear.

ATES systems are regulated in the Water law. This law regulates the management of

surface water and groundwater on a national level. Concerning ATES, this law states that it

is forbidden to extract groundwater for the use of ATES without a permit from the provincial

government.

The law also states that each province has to describe its water policy in a so-called

Provincial Water Plan. In this plan, each province has described a policy for ATES systems.

The policy describes the provincial vision on ATES and what conditions an ATES system has

to meet in order to obtain a permit. Further, there are rules about, for example, the maximum

infiltration temperature, energy balance, use of aquifers, water quality etc. Appendix A gives

a summary of the most important rules per province.

An ATES system is not allowed to have negative influence on other interests. These interests

are (inter alia) drinking water extracting plants, nature, archaeology, ground (water)

pollutions, infrastructure and other ATES systems.

Decree on Shallow Geothermal Energy (SGE)

On july 1th 2013 the decree on SGE has been effectuated:

The municipality will become the authority for GCHP systems.

New GCHP systems have to be reported to the authorities.

For systems with a capacity below 70 kW, only a declaration is needed.

If a system has a capacity that is higher than 70 kW, a permit is needed. This permit

will be issued by the municipality as well. The municipality decides if they allow the

system or not. There are no permit requirements attached to the permit, like for ATES

systems.


30

For the application of a permit, a description of the expected effects of the intended

system has to be included.

For GCHP systems that are already constructed, it is not compulsory to register.

Furthermore, the decree foresees the implementation of geothermal energy systems in

spatial planning. This is done by creating the possibility to designate the so called ‘areas of

interference’. Through using these areas, the interference between different systems can be

prevented. The municipality is allowed to designate these ‘areas of interference’. These are

zones where the amount of SGE systems is or is expected to be high in a way that the

application of SGE systems is or will be problematic due to a lack of space. Spatial planning

of the subsurface in these zones is necessary. In these ‘zones of interference’, all BTES

systems require a permit. The reason for this is to prevent smaller and energetically less

favourable BTES systems from frustrating the use of big ATES systems.


The propertyowner does not ‘own’ the heat and cold beneath his propertysurface. The right

to use geothermal energy (hence harvest heat & cold) is regulated by permits and may

include surface beneath neighboring properties.

Balancing heat & cold

With the exception for small GCHP systems. SGE systems need to maintain balance

between the amount of heat & cold that is added to the underground.

Belgium

For Belgium, compared to the description in the 2006 inventory (groundreach project) the

legal framework in Belgium for ATES systems has not been changed.

The utilization of shallow geothermal energy in Flanders is regulated by the 6 February 1991

Order of the Flemish Government concerning Environmental Licences (VLAREM I).

Vlarem I, divided into sections, determines when an environmental permit must be

requested. Depending on the level of nuisance, the project is classified in one of the three

classes:

Class 3: no permit, but only a notice to the Municipality;

Class 2: a municipal permit;

Class 1: a provincial permit.

Specific guidelines are applicable for the use of heat pumps (Vlarem, chapter 16.3:

installations for the physical threat of gases). Furthermore, the installation of the ground

source system is governed by Vlarem, chapter 55.6.

For groundwater systems, it’s obliged to have a reinjection well that returns groundwater

in the same aquifer as the extraction well. For vertical loop systems, it’s obliged to have an

announcing at the local government for shallow loops (<50m) and to submit a permit demand

to the provincial government (>50m). For horizontal loop systems, no permit requirements

are required.


31


No information has been received.



Italy

The Legislative Decree 11st February 2010 n. 22 reorganizes Italian regulations on

geothermal energy and for the first time introduces the concept of SGE in the Italian

regulations and repeals the Law 9th December 1986, n. 896. This 2010 decree has divided

geothermal resources into high (T>150°C), medium (90°C<T<150°C) and low enthalpy

(T<90°C). With this Decree, medium and low enthalpy resources, with a thermic capacity

lower than 20MW attainable at the defined temperature of 15°C, are defined of local interest,

i.e. they compete to the Regional Authorities.

According to this new regulatory framework SGE applications are not subjected to mining

regulations and are within Regions or other delegate local authorities. Regions have to

regulate SGE applications and may adopt simplified procedures.

The Legislative Decree 11st February 2010 n. 22 establishes that in case of lack of regional

regulations about SGE applications, it is valid national regulation without simplified

procedures. In fact, the Decree 19th July 2011 foresees minimum requirements for

interventions to reduce energy consumption for end-uses and in particular for SGE

applications. Then, the Legislative Decree 3rd April 2006 n. 152 disciplines the use of water

in the open loop systems.

These requirements are valid unless there are stricter regional regulations. At the moment,

there is a partial lack in the regional and national regulatory frameworks concerning issues

related to the installation of SGE systems in residential and non residential sector. This

implies that the regulation about low enthalphy geothermal applications differs among

different regions in Italy.

ATES systems

The installation of an open loop system requires the following authorizations:

the use of public water resources (Regional Regulation 41/2001), which can occur

against the payment of an annual fee, assimilated to either industrial or domestic

water use (Regional Law 3/1999);

the authorization to install a well;

the authorization for discharging groundwater in the aquifer, released by the

Province.

The authorization to discharge groundwater has to comply with the national regulation Dlgs.

152/06 which states that groundwater has to be re-injected in the same aquifer where the

withdrawal occurred and that the water has to maintain identical chemical characteristics.

GCHP systems


32

Authorizations for closed loop systems are released by the “Technical Basin Service” of the

Region. The applicant should submit the technical general report, a rough plan of drillings,

and proper maps. The TBS may require explanations and integration of these documents.

On the other hand, plants with a thermal capacity lower than 1000 kW, as well as closed loop

plants are excluded from regional environmental screenings procedure and only require a

communication to the Municipality (RER, 2013).


At the moment ownership of indigenous and introduced aquifer heat and cold is not defined

in the regulation.


It is not obligatory to balance the heat and cold storage, this has not been defined yet.

Spain

Geothermal Energy in Spain has been ignored traditionally, this is due to scarce information and knowledge, the interest in this energy had grown in recent years as a result of the growth of renewable energy over the past few years. After making a research of all the legislations and standards in Spain, we can conclude that despite of the efforts of the Spanish Government promoting laws for the RES, there are no specific standards for the Ground Source Heat Pumps. Anyway, because of the born of new projects and companies in the last years, seems that the situation of lack of standards will change soon. Moreover, the legislation for having permits for drilling is not uniform, having different criteria for every autonomous community (region) in Spain and making the market less attractive for the companies. This point should be regulated to make easier the market penetration. Therefore, there isn't a specific regulation to drilling, facilities, installers and users; but there an overview that soon will be published. The process to implementation this technology is complex in Spain due to administrative barriers and the lack knowledge. In the context of Directive 2009/28/CE and European efficiency criteria running up to 2011, a new range of laws and national directives (particularly the 2011- 2020 PER) have set objectives and figures for the sector, given both its potential and the interest it has generated. Nevertheless, the current crisis in the construction sector coupled with the introduction of a strong set of legislative measures (that do not discriminate between sources and technologies), which show a tendency to reduce the system costs pose a serious threat to our sector’s ultimate takeoff.






33

UK

For the UK legal framework information was used from the UK Environment Agency

(www.environment-agency.gov.uk/)

ATES systems

Permits for ATES include the following key stages include:

a pre-application discussion

a groundwater investigation consent

a full abstraction licence

an environmental permit to discharge – with temperature limits

It is likely to take up to six months before you can get your scheme up and running, possibly

longer. For some of this time you will be waiting for us to review and decide on your

applications, but you will be managing the aspects that usually take the most time: drilling the

boreholes, testing the boreholes, and then completing the work.

GCHP systems

the UK Environment Agency doesn’t regulate closed-loop schemes but they expect all GSHC

systems to follow good practice. Under the Environmental Permitting Regulations 2012 they

can place controls on the use of hazardous substances in a sensitive area. A sensitive

location would be:

within a defined groundwater source protection zone 1

within 50 m of a well, spring or borehole used for drinking water

on land affected by contamination

close to a designated wetland site

within 10 m of a watercourse

close to other GSHC schemes

near to a septic tank or cesspit

General

In the UK government policy favoured air source heatpumps over ground source heatpumps

and so the national market responded accordingly. These reducing sales, which decelerated

further through 2011 & 2012, have been exacerbated by strictly controlled Government

interventions through the Renewable Heat Incentive for the commercial ATES sector and

Renewable Heat Premium Payments for the domestic ATES sector. Both policies are

currently under review so that they lead to growth for commercial & domestic rather than

falling sales (source : GEO.POWER project).


There is no precedence in UK legislation over the ownership of introduced aquifer heat.


The Environmental Agency considers a temperature change of less than 2°C (considering upstream dilution of the temperature change) in a river to be acceptable.

http://www.environment-agency.gov.uk/


34

3.2.3 Socio-economic parameters

Germany

So far there haven’t been studies focusing on ATES systems in Germany. In total there are

290.000 shallow geothermal systems (including geothermal collectors, geothermal probes

and storages) with a maximum capacity of 3.100 MWth.

So far there have not been any cases of space competition. As described in the legislation

chapter there are guidelines which are used by the state authorities to regulate the distance

between geothermal probes (closed system).

Well temperatures vary largely over the whole area in Germany (between 6 – 16 ºC).

There are no subsidies that specially target to financially support the installation of ATES

systems in Germany. However there are some possibilities to get financial aid for ATES

either within a house construction or renovation plan or through programs targeting heat

pumps:

1. Financial support through earmarked credits for components of renewable heating

from the KfW-Bank.

2. Financial support through earmarked credits for the construction or purchase of a

“KfW-Efficient Building” from the KfW-Bank.

3. Pilot and test sites for R&D can be funded by various programs of the German

Federal Ministries.

In 2011 district heating of German households was 44 TWhth which is 7 % of the total

energy consumption of households. In the past seven years there hasn’t been a particular

growth or reduction of the portion of district heating.

The strongest competitor for ATES systems is the established system of heating existing

households based on fossil fuels. Condensing Boilers with very high efficiencies burning oil

or gas still possess huge financial advantages and have also seen a large growth. The large

effect on efficiency, financial subsidies from the government, the existing natural gas grid and

also the simplicity of replacing an old boiler with a condensing one are the main reasons for

house owners to stick with or even change to natural gas. According to the “Initiative Erdgas

pro Umwelt” (initiative natural gas for the environment) 3 million households have a heating

system older than 18 years. The initiative emphasizes, that a change to a more efficient

boiler technology can achieve 30 to 50 % energy reduction.

The Netherlands There are approximately 1600 open ATES systems in the Netherlands. The number of

closed loop systems is unknown, estimations vary between 20.000 – 40.000. Thermal

capacity of closed loop systems is between 50-100 kW, some may be bigger. The average

capacity of open systems is around 200m3/hr.

Space competition between ATES systems (open and closed) is an issue in larger cities and

in greenhouse areas.


35

Water temperatures vary between 6-18 ºC.

There are no specific subsidies available for ATES systems. However tax benefits can be

given when ATES systems are installed (EIA, energie investerings aftrek).

Some bigger cities have district heating in parts of the city (e.g. Amsterdam, Utrecht,

Rotterdam, The Hague, Deventer, Enschede)t, and it is expected to grow. These are all high

temperature systems

Smaller ATES systems are subject to a strong competition of other types of energy systems,,

e.g. air-air heatpumps or solar collectors. For the bigger buildings which also require cooling,

there are less sustainable alternatives.

Belgium

Exact numbers for existing ATES systems are not available. According to the ODE

(organization for durable energy, www.ode.be) the

number of sold heatpumps (ground)water/water is 1.148. This number consists of both

closed loop and open loop systems.

The situation where the demand is larger than the capacity of the underground, which leads

to interference between ATES systems, is not yet known in Flanders.

Common water temperatures in hot and cold wells are comparable to the situation in the

Netherlands and vary between 8 and 20 degree Celsius.

Subsidies are available for heatpumps; the grid administrator may give subsidies when heat

pumps are installed. Tax advantages may also apply when heatpumps are used in private

houses.

District heating is used in Flanders and the situation is comparable to the Netherlands. Exact

numbers are not given in response to this questionnaire.

Italy

In the whole Northern Italy, the use of low enthalphy geothermal resources is increasing. For

example, in Lombardia, 395 plants either closed loop or open loop, of which 366 are plants

with 1 up to 5 boreholes. In Lombardia, each geothermal plant at a shallower depth than 150

m bgl needs only to be registered, while deeper geothermic plants need a permit from the

Province in which they are to be installed (http://www.rinnovabililombardia.it/home).

In Emilia Romagna, up to June 2012, 105 systems were installed, of which 87 closed loop

systems (84 vertical and 3 horizontal), and 18 open loop systems (Regione Emilia Romagna,

2012).

So far there have not been any cases of space competition.


36

Average soil temperature in Emilia-Romagna at 100 m bgl ranges between 12 and 14°C,

below which the temperature rises with a gradient of 2-2.5 °C (RER, 2012) per 100 m???.

Common ∆T used in open loop plants are 4°C (RER, 2013).

As of June 2012, there were subsidies at the national level consisting of:

55% tax relief over a 10 year period for energy related upgrades, as from Decree

19/Feb 2009, prolonged till 2012 with the Decree 6/12/ n.201.

Feed-in tariff for electric heat pumps, as from del. 348.07/2010 from the Electric and

Gas Energy Authority

Rotary of revolving funds for measures taken to fulfill the commitments of the Kyoto

protocol (Document 16/02/2012) for low enthalpy geothermic plants with thermal

capacity up to 1MWt.

At the moment the prolongation of these incentives is under discussion at the national level.

District heating is widely used in Northern Italy’s regions Lombardia, Emilia-Romagna,

Piemonte, Veneto and Trentino Alto-Adige. In Emilia-Romagna district heating is available in

most of the largest cities (Reggio-Emilia, Forlì, Modena, Bologna, Ferrara, Imola, Parma,

Cesena, Ravenna). Thermal energy is mainly derived from natural gas, with the exception of

Ferrara where a geothermal system is employed (as described above).

In Emilia-Romagna, ATES systems have a good potential for application which is probably

limited by a clear regulation and by the duration of the incentives. Closed loop systems

probably have an even higher potential –and indeed have already been installed in larger

numbers- as they require a less intensive administrative procedure.

The main application possibilities of combinations with ATES systems are:

- remediation activities in suitable sites;

- recovery of thermal energy from industrial cooling waters;

- photovoltaic systems.

Spain

The following table provides a summary of assessed geothermal resources in Spain:

Type of use

Type of reservoir

Recoverable stored heat

(105 GWh)

Power (MW)

Thermal

Low temperature (total resources) 15,682 7,710.320(MWth)

Low temperature (usable) 160 57,563 (MWth)

Electric

Medium temperature (total resources) 541 17,000 (MWe)

Medium temperature(studied) 54 1,695 (MWe)

High temperature (studied) 1.8 227 (MWe)

Enhanced geothermal systems (known

areas)

60 745 (MWe)

The total energy in Spain is:

Closed-loop geothermal systems installed is estimated at about 60MWt.

Open-loop system installed is estimated on 90MWt.

The common thermal capacity of these systems is 15 Kw.

The volumes of groundwater use on the system are:


37

From geothermal water: 0,018 - 0,045 l/s kWt

From hot water: 0,045 - 0,054 l/s kWt

So far there have not been any cases of space competition.

The common temperature of the water aquifer is 16 ºC (can range between 12-20º). In the

hot wells is increased to 31ºC, whereas in cold wells the temperature is decreased to 8ºC.

UK

There were four new proposals for open loop GSHP systems in central London in 2011, all of

these went on to become investigations during the year, with one more proposed site from a

previous year being investigated as well.

There was one new active scheme in 2011, which is the fewest number since 2003. A large

number of scheme proposals were withdrawn in 2011, this largely reflects the London

Underground proposals. It can be seen that from inception to operation a ATES scheme can

take several years to bring to fruition within the UK with the number of proposals and

investigations significantly larger than the number of schemes that become active.

In the UK questionnaire the trends in applications, investigations and active schemes for the

past few years, and the locations of schemes proposed in 2011 in relation to existing

schemes (active, investigative, or proposed) are included. It can be seen that the rate of new

proposals and investigations under way has stabilised over the past few years forming a

steady increase, after very rapid increases in earlier years, while the rate of schemes

becoming active is slowing.

The Environmental Agency wishes to explore the possibility of baseline groundwater

temperature monitoring to create a dataset so that long terms trends can be observed and is

also considering options for the routine collection of water temperature records of ATES

schemes, again to see what, if any, changes of temperature occur.

There are two levels of subsidy currently in the UK. The first is for domestic heating; these

are typically under 50kwH and are primarily controlled through the energy saving trust

(www.energysavingtrust.org).

The second is the Renewable Heat incentive (RHI) for industrial and commercial properties.

The governing body for this is Ofgem. (www.ofgem.gov.uk//environmental-

programmes/renewable-heat-incentive-rhi) Subsidies can be negotiated with them over the

scope and size of the project.

Heating for multiple occupancy areas is still in its infancy here in the UK. The primary

focus comes from sustainability targets attached to new housing redevelopment

schemes (such as London’s Riverside quarter redevelopment) which have brought

the use of this technology into focus.

http://www.energysavingtrust.org/

http://www.ofgem.gov.uk/environmental-programmes/renewable-heat-incentive-rhi

http://www.ofgem.gov.uk/environmental-programmes/renewable-heat-incentive-rhi


38

3.2.4 Barrier assessment

Germany

Several barriers against wider deployment of shallow geothermal energy can be identified for

Germany. They can be classified mainly into the sectors of information, economy, and

regulation. It has to be stated that regulatory problems (overregulation) eventually might

result in becoming an economic barrier also.

Informational barriers

Heat Pumps as such are known much more widely in the general public today than in the

past. Also the negative image heat pumps had after the first market crash in the beginning of

the 1980s, mainly caused by poor design and installation quality as well as poor heat pump

reliability, today is no longer a factor. Meanwhile the heat pump achieved the image of a

clean, reliable heating and cooling technique. Some information deficits today can still be

detected with some of the installers of classical heating system (plumbers), and with persons

in regulatory authorities. However, the situation with the installers is rapidly becoming better,

and also the available information sources both on the building and the ground side are

becoming more and better.

Economic barriers

The most evident barrier in this group is the development of the price for electricity for the

private consumer in Germany that went up steadily (Figure 5). But it is not only the general

increase, which in a similar way affects all heat sources, but also the case that special heat

pump tariffs are disappearing. While until about the year 2000 in most regions favourable

tariffs for base‐load electricity3 were available in the price range of 100‐150 €/MWh, specific

tariffs for GSHP are no longer available in many places. Instead of about 100 €/MWh, the

owner of a newly installed GSHP might see up to 250 €/MWh in his electricity bill.

Another economic barrier is arising indirectly from the regulatory process. Limiting clauses

(e.g. minimum permissible temperature, maximum drilling depth) and requirements for site

investigations or monitoring are adding to the cost of the final system (cf chapter 0). Some of

these clauses are to be switched of remotely by the utility in peak hours, and heating secured

by buffer storage justified and understandable, while others might be reduced or even lifted.

Also fees and additional administrative cost can rise to the level of an economic barrier in

individual cases.

General items concern the inadequacy of financial support systems and some lengthy

environmental licensing procedures with uncertain chances. Also the lack of skilled workforce

became apparent when the highest market growth occurred in 2006/07. Meanwhile

training and education has been strengthened in Germany.

The Netherlands

In the Netherlands several barriers are encountered. These are listed below.

Permit procedure ATES systems

The permit procedure for an ATES system is about 8 months and can be quite costly due to

the consultant costs that are involved. Because of this long procedure it is sometimes difficult

to implement an ATES system in a construction project. It happens regularly that a developer


39

wants to implement ATES in a late stage. Unfortunately this is not always possible, because

due to the long procedures the permit would not be given before the construction is finished.

Investment costs

The investment costs for SGE systems are higher than for traditional heating and cooling

installations, mainly when SGE systems are used in renovation projects.

That the advantages that a SGE system can bring outweigh the extra investment costs is too

often forgotten:

Due to lower operation costs, the payback period is in general 3 to 7 years;

SGE systems have a green image;

SGE systems realize a CO2 emission reduction of 25 to 50%;

SGE systems improve the comfort of houses due to acclimatisation in both winter

(heating) and summer (cooling);

It’s a proven technique to meet the EPC normative.

Quality of systems (negative reputation)

Currently, only for drilling companies certification is obligatory. But the realization of SGE

system involves much more than only the drilling. Unfortunately, it happens more than

occasionally that an amateur, that has no or little knowledge of the installation of SGE

systems, realizes such a system. As a result, the quality of SGE systems is very often not as

good as it supposed to be, with bad performance as a result. This results in a negative

reputation for SGE.

Exploitation of systems

Unfortunately owners of SGE systems (and mainly ATES systems) don’t spend a sufficient

amount of time, money and/or interest on the exploitation of their system. The consequence

is that many ATES systems do not perform as they are supposed to, which also results in a

negative reputation for SGE.

Good management, good exploitation contracts and transfer of knowledge could resolve this

problem. Also the authorities can improve the performance of systems by controlling the

systems regularly. The permit dictates the monitoring of several parameters that influence

the performance of the system, but too often it happens that the authorities do not check

these.

Crowded subsurface

For example, in city centres there is a lot of underground infrastructure. This can be (metro)

tunnels, cables and piping, but also other SGE systems, archaeology and soil or

groundwater pollution. Because of all the interests that are present in the subsurface, it can

be difficult to implement a SGE system on a certain location. Subsurface spatial planning is

therefore necessary.

Interference

It is not allowed for a new SGE system to have a negative influence on existing SGE

systems. Due to this rule it is sometimes not possible to realize a new SGE system. This

happens for example in busy areas like city centres. SGE is here outgrowing its success.

This problem is related to the previous topic.


40

GCHP barriers

Until july 2013, there was no legal framework for GCHP systems. Therefore it was quite easy

to make these systems and a quick turn-key market has risen. But there is no control on the

design and realisation of these systems and it happens quite often that something goes

wrong. The most common problems are the following:

The system design is not adequate, so the system isn’t able to deliver the needed

amount of heat. This happens mainly with bigger systems, where the demand from

the subsurface is bigger and the loops are often placed too close to one other;

The underground part (loops) and heat pump are not well incorporated. The

consequence is that the system doesn’t function well and the user doesn’t have the

comfort that is asked for.

Belgium

The barriers defined in Ground-Reach project deliverable 9 are still valid.

Extract from Deliverable 9:

“A great barrier for GCHP-systems consists in the lack of knowledge of these systems.

Compared to gas boilers, GCHP installers consider heat pumps as a difficult technology.

They also have to turn to a specialized drilling company to perform the drilling activities.

Coupled with bad experiences in the past, this makes an important barrier for the widely

spread introduction of heat pumps in the Belgian market.

Price can also be seen as a second great barrier for implementing GCHP-systems. Heat

pumps, and certainly ground-coupled ones, demand a significant financial effort (initial

investment). Belgium has another great disadvantage which has its impact on the investment

price: there are just a few geothermal drilling firms that are experienced in geothermal

drillings (groundwater, vertical heat exchangers). Most of the drilling firms are specialized in

drillings for groundwater extractions and probes for geotechnical research.

Although these GCHP-installations are able to realize a break-even at 10 years, the initial

investment stays pretty high and heavy to take.

A third less important barrier is formed by the permits. Both open as closed systems require

a permit in order to allow the drilling activities. The administrative approval takes up a lot of

time as a function of the size of the GCHP-system from 1-4 months.”

Italy

The development of SGE systems in Italy is mainly hindered by information barriers. These

information barriers influence urban planners and in general potential clients. Urban planners

do not usually consider SGE systems during their planning activity, because they ignore

benefits associated with SGE applications.

Consequently, the installation of SGE systems becomes more complicated. Potential clients

are confused because they cannot understand the advantages of using low temperature

geothermal resources and recognize “good” practitioners, e.g. designers and installers,

among several actors’ market. Sometimes, potential clients have to face high costs to carry

out feasibility study.


41

The analysis of Ground Reach project identified also administrative barriers in 2007. In

particular, this study highlights the delayed in the realization of GCHP systems caused by the

complexity of procedures and related costs.

Spain

The main barriers for the application of ATES systems, determined for Spain, are: - Complex regulatory and administrative issues, differing per region; - No full knowledge of geothermal resources in Spain; - Long processing times of environmental and water laws; - No specific training of this technology - No social acceptation; the geothermal technology has been criticized in Spain due to

electric energy consumption. - In open-loop systems, the water from the aquifer that is used is considered as waste;

hence this water has to be treated as such.

UK

The current trend for ATES in the UK is still in its infant stage legislatively therefore the scope

for more stringent legislation especially regarding the monitoring and control of temperature

controlling is a possibility.

The UK is legally committed to meeting 15% of its energy demand from renewable sources

by 2020 and the National Planning Policy Framework, published by the government in March

2012, makes it clear that local authorities must design their policies to maximise renewable

and low-carbon energy development.

The London Plan goes further, stating in section 4A.7 that boroughs should in their

development plan document adopt a presumption that developments will achieve a reduction

in carbon dioxide emissions of 20% from onsite renewable energy generation therefore there

is an impetus to use this technology as along with many others technology.

3.2.4 Opportunity assessment

The GEO.POWER project has identified the following general opportunities for

transformation of the European SGE industry:

To transform a renewable energy market, five measures need to be in place, 3 policy

measures supported by 2 flanking measures which engage the industrial sector and the

general public. The 3 policy measures are:

1. Financial incentives. These are especially important to the existing properties market

and need to be set at a level just above the limit which tips the end user over into a

purchasing decision.

2. Regulation. This is particularly relevant to the new build market whereby

housebuilders must install a certain amount of energy efficiency and renewable

energy measures to obtain planning permission.


42

3. Quality schemes. In many EU member states, the construction industry is frequently

associated with low quality workmanship and make-money-fast traders. Quality

certification schemes such as the pan-European Qualicert scheme

(http://www.qualicert-project.eu/) can assist in bringing together diverse qualification

requirements and build customer confidence in registered installers.

The two flanking measures are:

1. Training. The building services and construction sector is skilled at installing gas & oil

boilers and general building works. However, except for a few pockets of competent

installers, it does not have much experience of the particular needs of heat pumps

and the grounds works associated with ground collector installation. Good design and

installation courses need to be provided by the training sector to address these

market gaps.

2. Public awareness. This could be considered the most important of the above 5

measures. Engaging the customer in the purchasing decision is the point where

market growth and transformation occurs.

3.3 Main barrier analysis

Regarding the results of the inventory, possibilities for use of ATES technology seem quite

obvious; see also previous chapter for experiences in the Netherlands and next chapter for

Europe-wide application potential. However, for a successful spreading of the technology, it

is essential to overcome existing barriers. Based upon an analysis of the inventory

outcomes, main barriers were pinpointed.

For the barrier analysis results from the REGEOCITIES, the GEO.POWER project and the

questionnaires have been used. In general a correlation between market maturity and the

identified barriers for SGE systems can be seen.

For countries with an immature market the following barriers can be identified as the most

important ones to cope with:

1. Public awareness & lack of knowledge: The biggest barrier for SGE-systems (and

ATES systems in particular) is the lack of experience and familiarity with these

systems and heatpumps in particular. Compared to gas boilers, HVAC installers

consider heat pumps as a difficult technology. They also have to turn to a specialized

drilling company to perform the drilling activities. Coupled with disappointing

experiences in the past, this makes an important barrier for the widely spread

introduction of heat pumps in the European market.

2. Legislative barriers. As described in chapter three, the lack of regulations adapted to

SGE systems can be a great barrier for SGE systems. Long and uncertain permit

procedures can occur. Also the lack of quality schemes for SGE systems can be a

barrier for public confidence and trust in the new technology of SGE systems.

3. Large initial investments can be seen as a great barrier for implementing SGE

systems. Heat pumps, and certainly ground-coupled ones, demand a significant


43

financial effort (initial investment). Many countries have another disadvantage which

has its impact on the investment price: there are just a few geothermal drilling firms

that are experienced in geothermal drillings (groundwater, vertical heat exchangers).

Most of the drilling firms are specialized in drillings for groundwater extractions and

probes for geotechnical research. Although SGE systems are able to realize a break-

even within 10 years, the initial investment stays pretty high and heavy to take.

For counties with a more mature, grown market the following barriers can be identified as the

most important ones to cope with:

1. Interference between ATES systems. In crowded urban areas where aquifer thermal

energy systems (ATES) compete with each other for the available space in the

subsurface: the demand can overgrow the available capacity, or the subsurface

planning is immature. That all can lead to interference between ATES systems and

disappointing efficiency, This phenomena mainly exists in larger cities.

2. Interference with polluted groundwater. Often it is prohibited to operate an ATES

system in or near polluted groundwater. Because both ATES systems and polluted

groundwater are mostly concentrated in urban areas this can be a serious barrier.

3. Shifting opinions on the negative impact from SGE systems on groundwater quality.

In the Netherlands the opinion on the possible negative impact from SGE systems on

the groundwater quality has greatly increased in the past 10 years. This is mainly due

to the fast growth of the systems. In expanding markets this is possibly a serious

barrier.

For all countries, regardless of the market maturity the following barriers can be seen:

1. Quality levels. Currently, certification is not obligatory (this will change in The

Netherlands in 2014). Proper efficiency of SGE system involves a good design and

operational control for the entire system. Unfortunately, it frequently occurs that

unqualified companies, realize ATES or GCHP systems. As a result, the quality of

ATES systems is very often not as good as it is supposed to be, with disappointing

performances as a consequence. This results in a negative reputation for SGE

systems.

2. Relating to the quality levels, the companies which install SGE systems are often only

delivering a part of the system, like the heatpump or building installations. Other

companies install the wells. Because of this separation in knowledge and skills it is

difficult to obtain an integrated and well adapted system during construction.

3. Unfamiliarity with the underground an its characteristics. SGE systems rely on the

underground for storing heat & cold. Because most companies are specialized in the

building installations, unfamiliarity with the underground may be the cause of sub-

optimal designs.


44

In the table, barriers are summarized in relation to the SGE market status: Emerging market

(IT, UK, SP)

Growing market

(DE, BE)

Mature market (NL)

Public awareness & lack of knowledge X (X)

Legislative barriers X X

Large initial investments X X

Segmented installer market X X (X)

Unfamiliarity with the underground X X (X)

Quality levels X X X

Shifting Opinions regarding SGE systems X X

Interference between ATES systems (X) X

Interference with polluted groundwater (X) X


45

4 LINKING PRECONDITIONS TO GEOGRAPHY (D2.2)

4.1 Method

In this WP a quickscan for linking geographical preconditions is conducted. It is planned to

further elaborate this later in this project. For now 4 types of geographical information are

combined to create European ATES suitability maps.

- Groundwater availability (from the WYMAP project (BGR & Unesco, 2008; Richts et

al., 2011))

This map indicates the applicability of ATES technology. The source data is not the

most suitable for ATES applicability but It gives a nice indication. Note that in the

middle range of the scale of applicability the actual conditions in some areas might be

different. Further research is necessary to improve reliability and the maps

applicability.

- Climate classification (from Rubel et al., 2010)

Based on the climate classification of Europe, distinction is made between areas with

predominantly heating demand, cooling demand or more or less balanced heating

and cooling demand. Also for this data a better classification can be obtained by

taking into account different types of buildings.

- Urbanization (from EEA data products)

The urbanization data from the European Environment Agency (EEA) was used to

link potential to where the major demand for ATES technology is.

- Surface water bodies and courses (from EEA data products)

The surface water data is used to get insight in the potential for combining with heat

exchange with surfaces water. Surface can be used for dumping or extracting heat. In

this map only the larger water courses and bodies are represented.

Next to the suggested improvement above, we propose some case studies of several

archetypical cities, in which other geographical data can be combined: Local (smaller) water

bodies, drinking water and sewerage water infrastructure, soil contaminations etcetera.

4.2 Results

4.2.1 ATES Suitability

The charatersiation of the WHYMAP data is translated to ATES suitability according to the

relations in table 4.1. These relations are made based on expert judgement, knowledge

about ATES projects and suitability in specific areas and local/National suitability maps.


46

Table 4.1 Aquifer and water availability linked to ATES suitability

The whymap data says something about the presence of aquifers and water, when they are

both there applicability of ATES has highest change. It was tried to make as good as

possible matches between known suitable area’s and the whymap classification. The main

picture of the European map is a good representation of the suitability. Nevertheless, in

some local situations especially in the 3-7 range suitability may differ from what is indicated

in this map. The result is given in an European overview in figure 4.1.

Figure 4.1 ATES suitability Europe

4.2.2 Heating/cooling demand

Climate classification

Next to where the potential is for applying ATES it is also of importance to know where

potential demand for ATES is. ATES can supply in both heating and cooling. So area’s

where there is a moderate sea or land climate ATES is most suitable. In tropic and artic

conditions it is not suitable, in the areas in between suitability depands on local conditions

Whymap class. Subsurface Recharge ATES suitability

11 major groundwater basin < 2 mm/a recharge 3

12 major groundwater basin 2 - <20 mm/a recharge 5



15 major groundwater basin >= 300 mm/a recharge 10

22 area with complex hydrogeological structure < 20 mm/a recharge 2

23 area with complex hydrogeological structure 20 - <100 mm/a recharge 2

24 area with complex hydrogeological structure 100 - <300 mm/a recharge 4

25 area with complex hydrogeological structure >= 300 mm/a recharge 5

33 area with local and shallow aquifers < 100 mm/a recharge 2

34 area with local and shallow aquifers >= 100 mm/a recharge 3


47

and the type of building. Based on the climate classification according to Rubel/Koeppen-

Geiger, the classification for heating and cooling demand is determined as given in table 4.2.

As can be seen from figure 4.2 and 4.3 the climate conditions are suitable for ATES at a

limited surface space area of the world, while for Europe the conditions are suitable in about

half of the surface space.

Figure 4.2 Dominating demand for space heating and cooling, world


48

Figure 4.3 Dominating demand for space heating and cooling, Europe


49

Table 4.2 Climate classification linked to domination heating and cooling demand

Urban area’s

ATES can be used for energy saving for space heating and cooling, so most demand for

ATES systems is in urban areas. Urbanization data from the European Environment Agency

was used to get insight in how many surface space of European cities is in suitable area’s;

both climatic and ATES. In figure 4.4 the urban areas are shown together with the ATES

suitability.

GRIDCODE KG Desciption Dominating demand

11 Af Af Equatorial rainforest, fully humid Pmin ≥ 60 mm Cooling

12 Am Am Equatorial monsoon Pann ≥ 25(100−Pmin) Cooling

13 As As Equatorial savannah with dry summer Pmin < 60 mm in summer Cooling

14 Aw Aw Equatorial savannah with dry winter Pmin < 60 mm in winter Cooling

21 BWk Cooling

22 BWh Cooling

26 BSk Cooling

27 BSh Cooling

31 Cfa Heating and cooling

32 Cfb Heating and cooling

33 Cfc Heating and cooling

34 Csa Cooling

35 Csb Cooling

36 Csc Cooling

37 Cwa Heating and cooling

38 Cwb Heating and cooling

39 Cwc Heating and cooling

41 Dfa Heating

42 Dfb Heating

43 Dfc Heating

44 Dfd Heating

45 Dsa Heating

46 Dsb Heating

47 Dsc Heating

48 Dsd Heating

49 Dwa Heating

50 Dwb Heating

51 Dwc Heating

52 Dwd Heating

61 EF ET Tundra climate 0 ◦C ≤ Tmax < +10 ◦C Heating

62 ET EF Frost climate Tmax < 0 Heating

GROUP E: Polar and Alpine climates

BW Desert climate Pann ≤ 5 Pth

BS Steppe climate Pann > 5 Pth

GROUP A: Tropical/megathermal climates

GROUP B: Dry (arid and semiarid) climates

GROUP C: Temperate/mesothermal climates

GROUP D: Continental/microthermal climates

Cf Warm temperate climate, fully humid neither Cs nor Cw

Cs Warm temperate climate with dry summer Psmin < Pwmin,

Pwmax > 3 Psmin and Psmin < 40 mm

Cw Warm temperate climate with dry winter Pwmin < Psmin and

Psmax > 10 Pwmin

Dw Snow climate with dry winter Pwmin < Psmin and Psmax > 10

Pwmin

Ds Snow climate with dry summer Psmin < Pwmin, Pwmax > 3

Psmin and Psmin < 40 mm

Df Snow climate, fully humid neither Ds nor Dw


50

Figure 4.4 Urban areas in Europe

Surface water

Surface water can also be used to collect or dump heat. In figure 4.5 the surface water

bodies and courses are depicted together with the urban areas to give an impression of the

potential.

Figure 4.5 Surface water in Europe


51

4.3 Conclusion

From the maps created several figures can be derived/calculated. The analysis applied on

the data are the following;

- Percentage of Europe is urban area [Wikipedia]

- Percentage of Europe where there is both heating and cooling demand [calculated]

- Percentage of Europe in suitable ATES area [Estimated]

- Percentage of Europe in both suitable ATES area and Heating cooling demand area

[Estimated]

- Percentage of urban area is in suitable ATES area [Estimated]

- Percentage of urban area in both suitable ATES area and Heating cooling demand

area [Estimated]

The results are given in Table 4.3.

Table 4.3 Climate classification linked to domination heating and cooling demand

From this table can be concluded that there is potential for ATES in quite a substantial

percentage of European cities. Almost all the suitable ATES area is also has a suitable

climate.

4.4 References

Rubel, F., and M. Kottek, 2010: Observed and projected climate shifts 1901-2100

depicted by world maps of the Köppen-Geiger climate classification. Meteorol. Z., 19,

135-141. DOI: 10.1127/0941-2948/2010/0430.

BGR & UNESCO (2008) - Groundwater Resources of the World 1 : 25 000 000.

Hannover, Paris.

RICHTS A., STRUCKMEIER W.F. & ZAEPKE M. (2011) - WHYMAP and the

Groundwater Resources of the World 1:25,000,000. In: Jones J.A.A. (Ed.): Sustaining

Groundwater Resources: pp. 159-173.

EEA ; European Environment Agency, http://www.eea.europa.eu/data-and-maps.

Downloaded in November 2013.

Figure km2 percentage of land area

Land area Europe 10.180.000 100%

Total urban area in Europe 153.544 2%

Heating and cooling demand area 5.000.000 49%

Suitable ATES ares (>6) 2.500.000 25%

H&C demand in suitable ATES area 2.000.000 20%

Figure km2 percentage of urban area

Urban area in suitable ATES area 50.000 33%

Urban area H&C in suitable ATES area 45.000 29%

http://koeppen-geiger.vu-wien.ac.at/pdf/Paper_2010.pdf

http://koeppen-geiger.vu-wien.ac.at/pdf/Paper_2010.pdf

http://dx.doi.org/10.1127/0941-2948/2010/0430

http://www.eea.europa.eu/data-and-maps


52

5 GERMAN TEST SITE & PILOT DESIGN DESCRIPTION (D3-A)

5.1 Description of building construction site

The site PalaisQuartier is located in the Frankfurt city center and brings the commercial,

shopping and cultural area together, which attracts large numbers of tourists every day. To

achieve a more sustainable climate installation compared to traditional buildings, the aim was

to extract heat from the ground, for heating, or inject heat into the ground for cooling, the

heat pump is linked to the underground through the ground system. Generally these systems

can be classified as open system, closed system or combined systems. To choose the right

system for installation, the following factors have to be considered [source: Dr. Erich Mands,

Dr. Burkhard Sanner, Shallow Geothermal Energy, UBeG GbR, Wetzlar]:

Geology and hydrogeology of the underground (sufficient permeability is a must

for open systems),

Area and utilization on the surface (horizontal closed systems require a certain

area),

Existence of potential heat sources like mines,

The heating and cooling characteristics of the buildings.

Open system generally consists of one or more pairs of tube wells that extract and

simultaneously infiltrate groundwater to extract or store thermal energy in or from the

subsurface by changing ground and groundwater temperature. The thermodynamic transfer

and storage works here by advection and conduction. Although the system is more efficient

for heating and cooling compared to closed systems (especially cooling can work directly

with cold water from the underground), there are more problems and risks for the

employment: it puts more stress on the subsurface and could cause unwanted chemical and

microbiological reactions, especially if the water turns out to be polluted. Due to lack of

experience with such systems in Germany, the investors are more restrained towards such

investments.

To avoid these barriers, a closed system was realized in PalaisQuartier by using energy

piles with closed circuits of water tubes in the energy piles which extract or store thermal

energy in the subsurface through conduction. The thermal influence of closed systems is

limited and is causing less temperature change in the ground and in the neighboring

properties. In this case it was considered to be more “safe” within the dense urban

environment as it causes less potential conflict areas with the neighbours. However, the

stakeholders realized that this would lead to a reduced effectiveness of the aquifers use.

Effective use of the subsurface brings many benefits in the densely urbanized districts. In the

future more effective use of ATES technologies must be promoted to avoid that every

individual is going to build a separate installation which could cause unwanted interferences

between the systems. This will allow the development of larger, more efficient energy storage

systems. As a first step the performance of the current system needs to be evaluated with

respect to energy efficiency and the influence of energy storage on the subsoil.


53

The PalaisQuartier, formerly known as FrankfurtHochVier, is a building complex in the city

center of Frankfurt, Germany. It was built from 2004 to 2011 and consists of four buildings:

Palais Thurn und Taxis (Thurn-und-Taxis-Platz 1) which was originally built from

1731 to 1739 by Robert de Cotte. From 2004 to 2009 it has been reconstructed as

a part of the Palais Quartier development by KSP Jürgen Engel Architects.

A 136-meter high rise office building Nextower, which is located in Thurn-und-

Taxis-Platz 6 and was also designed by KSP Jürgen Engel Architects and

Massimiliano Fuksas Architects. The construction began in 2004 and was

completed until 2009.

A 99-meter high rise hotel building Jumeirah Frankfurt. This five star hotel is the

first hotel in Deutschland belonging to the international hotel chain Jumeirah

Group in Dubai, located in Thurn-und-Taxis-Platz 2 and completed by KSP Jürgen

Engel Architects in 2011.

A shopping mall MyZeil, completed by Massimiliano Fuksas Architects in 2009.

Main site characteristics are presented in this table:

Part of the building Area

Thurn and Taxis Palais

3 storeys, plus an underground level

11.000 m2 (of which 2000 m

2 underground)

Office tower NEXTOWER

135m high, 32 storeys, plus two technical

floors

48.000 m2 (Mietfläche 32.000 m

2)

Jumeirah tower (hotel)

96 m high, 25 storeys

22.000 m2

Shopping center MyZeil

8 levels

77.000 m2

(of which 7.500 m2 stand

unterground)

Car park

4 underground levels

1396 parking spaces (of which 900 are

public)

Together gross external area: 226.000 m2

Gross cubic content: 982.300 m

3

Source: www.palaisquartier.de

Site location is shown in figure 5.1, an aerial photograph is presented as figure 5.2.

http://www.palaisquartier.de/


54

Figure 5.1 Site location of “Skyscraper PalaisQuartier” Frankfurt, Germany

The site with approx. 17.400 m2 is located in the area between the streets Stiftstraße, Zeil

and the Große Eschenheimer Straße. The Frankfurt Rundschau is situated on the North-

West of this building complex, with Telekom to the North-East. Beneath the complex lies the

largest underground car park in Frankfurt city center with 1.396 parkings.

Project area


55

Figure 5.2 Aero view of current use of “Skyscraper PalaisQuartier”

For preservation of the historical relics Palais Thurn and Taxis, its old façade elements

constructed out of sandstone have been dismantled and protected. The current and also

future height of Palais Thurn und Taxis is approx. 17,8 meter. The subterranean garage can

be accessed with the direct entrance. (See below figure 5.3)

Figure 5.3 Palais Thurn und Taxis

Behind the reconstruction of Palais stands a 135-meter high new office building Nextower

which consists of 32 storeys, plus two technical floors. Units of office space are up to 1.200

m2 per floor. 1 (See below figure 5.4)

1 http://www.palaisquartier.com/en/office-tower-nex-tower


56

Figure 5.4 Nextower

Next to the Nextower is the hotel building Jumeirah Frankfurt. This 96-meter high luxurious

chain hotel consists of one ground floor and 24 upper floors with 218 rooms in total. With a

direct entrance to its subterranean garage 1,396 carports are placed. 2 (See below figure 5.5)

Figure 5.5 Hotel Jumeirah

The shopping mall MyZeil is located in the eastern part of the PalaisQuartier area, on the

Zeil-Street, Nr.106. The total 8 floors consist of 6 upper floors, one ground floor and one

underground floor for more than 100 shops.3 (See below figure 5.6)

2 http://www.palaisquartier.com/en/hotel-jumeirah 3 http://www.palaisquartier.com/en/shopping-centre-myzeil


57

Figure 5.6 The shopping mall MyZeil

5.2 Soil and groundwater properties of building ground

5.2.1 Soil properties

The area is located in the Mainzer basin which is at the northern edge of the macro tectonic

structure Rheintalgraben. Both the tertiary soils and the bedrock which lies below the ground

surface with a depth more than 100 m are exposed to tectonic stress. Directly beneath the

artificial backfilling the quaternary layer is found, the thickness of which strongly depends of

the geomorphological situation. A thickness of approx. between 5 m and 10 m of this

quaternary layer is subject to the influence of the Main river bed, i.e. the groundwater flow. In

the north / northeast of Frankfurt city center the thickness of the quaternary part decreases

with the underlying tertiary soil layer to a layer thickness of only a few decimeters. According

to the soil profiles it contains the following typical construction layers which are in agreement

with the constructional experience in Frankfurt city center areas:

The first construction layer: back filling (approx. a thickness from 0,7 m to 4,7

m)

The second construction layer: sand and gravel (quaternary layer with a

thickness approx. from 0,5 m to 5,0 m)

The third construction layer: Frankfurt clay (tertiary hydrobien layer with a

thickness approx. from 0,15 m to 5,3 m)

The fourth and fifth layer: Frankfurt limestone (tertiary Inflated- and Cerithium

layer which is a sandy limestone of Miocene and rich in Cerithium, with a

thickness approx. from 0,1 m to 1,3 m).

According to the underground survey it was found that all the soil layers exist cross each

other in the subsoil.

5.2.2 Groundwater characterization

Below the construction site, the groundwater flows in two aquifers that communicate

indirectly through a soil layer with low permeability (Frankfurt clay). The upper groundwater

table is a free level which lies in the soil layer of quaternary sands and gravels at a depth of

about 94,5 mNN ~ 95,0 mNN existing about 6,5 m ~ 7,0 m below the surface (the ground


58

level surface in the middle of measurement points is about 101,5 mNN). The lower aquifer is

located in the Frankfurt clay or Frankfurt limestone. The storing layer of hydrobien is of

moderate thickness and includes the fragmented lime- or dolomite stone benches that are

highly aquiferous sediments. In the individual aquifers the pressure horizons are different and

these pressure horizons are formed partly with confined groundwater or formation water.

5.2.3 Permeability

The water permeability of the building ground was reviewed by WD Tests (Wasser-Druck-

Versuch, engl.: Hydrostatic test) in the boreholes and also through a pumping trial on one of

the ground water monitoring well. The soil profile has indicated that the soil layers of the

underground are mainly heterogeneous. The groundwater flows into the bottom layer of the

quaternary sandy gravels, and furthermore groundwater continues flowing through the

tertiary sands and the clefts of limestone as well as the dolomite stone benches that are

aquiferous, also the encountered algae lime reefs are water-bearing. The clays, marls and

silts of the tertiary layer are very unfertile, and have a sealing effect, so that in certain areas

the hydrobien sands and limestone layers are strained. The individual aquifer of the

quaternary and tertiary layers are, however, mostly connect with each other indirectly.

Permeability of each soil layer in the construction ground:

Quaternary sand and gravel: k = 1 ~ 5 · 10-4 m/s

Tertiary sand: k = 1 ~ 5 · 10-5 m/s

Tertiary clays, marls and silts: k = 1 · 10-8 ~ 1 · 10-9 m/s

Limestone- und dolomite stone benches: k = 1 ~ 5 · 10-4 m/s

At the base of quaternary sand and gravel the values mentioned above can be increased up

to k = 1 - 5 x 10-3 m/s in certain areas.

5.3 Geothermal situation and potential

5.3.1 Temperature conditions of construction ground and groundwater

According to our experience, the temperature of groundwater in Frankfurt am Main is approx.

10°C higher than the average groundwater temperature outside of metropolitan areas. The

groundwater temperature over the depth is relatively constant between 15,8°C at 8m below

the ground surface, and 17,7°C at a depth of 36m below the ground surface.


59

Figure 5.7 Groundwater temperature profile over the depth, measured on 18.05.2004

4

5.3.2 Hydraulic and thermal parameters of soil layers as used in the thermal-

hydrological model

Layer I+II – Back filling, quaternary sand and gravel

Horizontal permeability kxx = kyy = 1 · 10-4 m/s

Vertical permeability kzz = 1 · 10-5 m/s

Thermal conductivity λ = 0,6 W/(m·K)

Thermal capacity c = 1,5 MJ/(m³·K)

Layer III – Frankfurt clay (tertiary hydrobon layers)





Layer IV – Frankfurt limestone (tertiary inflate layers)





5.3.3 Hydrogeological and water management situation and effects

The project area is approx. 3km away from the outer edge of the nearest drinking water

reserve of Praunheim. Therefore, it is unlikely that the project PalaisQuartier has any effect

on the drinking water protection areas.

4 Professor Dr.-Ing Katzenbach, Dr.-Ing. Matthias Volger, Dipl.-Ing. Thomas Waberseck, Dipl.-Ing. Ulrich Adamietz, „Erläuterungsbericht

zur Erdwärmenutzung“. Ingenieursozietät Professor Dr.-Ing. Katzenbach GmbH, 16.02.2007, page 14.

0

5

10

15

20

25

30

35

40

45

10,0 12,0 14,0 16,0 18,0 20,0

Grundwassertemperatur [°C]

Tie

fe u

nte

r G

elä

nd

eo

berf

läch

e [

m]

Groundwater temperature [°C]

Dep

th b

elo

w g

roun

d s

urf

ace

[m]


60

5.3.4 The proposed geothermal energy use

The extraction of heat from the subsoil and groundwater within the project areas takes place

by conduction by using energy piles. These energy piles are small heat exchanger tubes that

are fixed to reinforcement cages installed at the inside of the shoring and foundation piles.

These small heat exchanger tubes are embedded in concrete and have no direct contact

with groundwater. No groundwater extraction is needed to supply the energy.

Each energy pile is equipped with two pipe circuits, and each pipe circuit has eight loops,

which are assembled individually to the distributors and collectors. The circuits can be

regulated and turned on/off individually.

The building project PalaisQuartier has three power houses that are connected via energy

piles with each other. The energy extracted from the underground has been used for heating

purpose and recooling for the combined heat pumps/coolers. The heating and cooling

systems are connected with the energy piles via the distributor/collector, piping network and

heat exchanger. There are 262 of the 302 foundation piles and 130 of the 543 shoring piles

were implemented as energy piles. There are 392 pieces energy piles in total. The technical

data of energy piles see below:

Energy piles:

Number of occupied foundation piles: 302 pieces, of which 262 as

energy piles.

Number of occupied piles in the shoring walls: 543 pieces, of which 130

as energy piles.

Max. power of energy piles in total: ~ 913kW

Heat transfer medium: Water

Dimensioning temperature difference: 3 K

Involved volume of heat exchange: ca. 120m3

Distributor of energy pile (for foundation piles): 16 pieces

Distributor of shoring piles (for piles in the shoring wall): 9 pieces

Pipes (according to DIN 8074/75)

Quality: S 5 / PN 16 / SDR 11, PE 100

Dimension: 25 x 2,3 mm

Operation pressure: 16 bar

Leakage test of system: in line with DIN 4279-7

The heat extraction rate is illustrated as an annual hydrograph of the pile performance (see

fig. 5.8); 262 of the 302 foundation piles and 130 of 543 shoring piles are built as energy

piles that are used as seasonal heat storage with a maximum capacity of 913 kW. The

annual energy for heating adds up to approx. 2.350 MWh, for cooling to approx. 2.410 MWh.

The system is operated in the seasonal pendulum with approximate energy balance. The

maximum power of energy pile system is 913 kW in both heating and cooling case.


61

Figure 5.8 Energy balance of the energy pile system

5.3.5 Energy piles simulation

To analyze the thermal influence of the energy piles in the ground below the building, a three

dimensional FE-model was simulated with an edge size x = 305 m, y = 300 m and z = 60 m

(see figure 5.9).

Figure 5.9 Three-dimentional FE Modell

5

Thermal development was calculated for the first five years of operation. Figure 5.10

illustrates a simplified subsurface model. The main goal of this model was to understand the

temperature changes in the border areas, where the construction of the energy piles could

bring negative influence towards the neighboring plots inside the dense downtown district.



-1000

-900

-800

-700

-600

-500

-400

-300

-200

-100

0

100

200

300

400

500

600

700

800

900

1000

Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez

Leis

tun

g d

er

Grü

nd

un

gs-

un

d V

erb

au

pfä

hle

[ k

W ]

Per

form

ance

of

fou

nd

atio

n-

and

sh

ori

ng

pil

es[k

W]

month


62

Figure 5.10 Simplified schematic diagram of layer models

6

Two main vertical measuring sections were simulated in the FE-model, one is located at the

south and another the east border of the construction, that correspond with the direction of

the underground water flow (from the north – northwest corner of the building towards the

south – southeast corner, and eventually flows into Main River). The underground water flow

was the main cause of the widening of the thermal influenced field outside the project area.

Due to the higher permeability of the Frankfurt limestone in comparison to the Frankfurt clay,

the main spread of the temperature was found in the limestone layer. As expected, the

calculated FE-model has shown that the highest thermal influence of the ground appeared in

the area where energy piles were especially densely positioned. It is understandable that the

most thermally loaded was therefore the core area of the high-rise office tower Nextower.

Figure 1.11 Two main measuring cross sections (L); Position of measuring points (R)

7

According to the measured ground water levels in the project area and based on a large-

scale groundwater observation the groundwater condition was assumed to be stationary. Its


zur Erdwärmenutzung“. Ingenieursozietät Professor Dr.-Ing. Katzenbach GmbH, 16.02.2007, page 16. 7 Professor Dr.-Ing Katzenbach, Dr.-Ing. Matthias Volger, Dipl.-Ing. Thomas Waberseck, Dipl.-Ing. Ulrich Adamietz „Ergebnisse der FE-

Berechnung zur thermischen Beeinflussung des Untergrundes“. Ingenieursozietät Professor Dr.-Ing. Katzenbach GmbH, 16.02.2007, layout

Nr.2.1.

Project PalaisQuartier Back filling / Sand and gravels

Frankfurt clay

Frankfurt limestone


63

flow direction in the model area is from North-North-West to South-South-East into the Main

river, the hydraulic gradient dropped from about 6,5∙10-3 to 2,5∙10-3.

Figure 2.12 Uninfluenced groundwater levels in model area8

The overall results of the five years simulating period showed that the thermal characters of

the ground below the buildings were influenced by a slight increase of temperature during the

first five years of building operation. This temperature increase was evaluated by all means

only in the nearest proximity of the piles and near the building in the direction of the

underground water flow respectively (see figure 5.13~5.20).



0 50 100 150 200 250-50

0

50

100

150

200

250


64

Figure 5.13 Temperature distribution after the first cooling period ∙ Horizontal section

9

9 Professor Dr.-Ing Katzenbach, Dr.-Ing. Matthias Volger, Dipl.-Ing. Thomas Waberseck, Dipl.-Ing. Ulrich Adamietz, „Ergebnisse der FE-


Nr.2.2.


65

Figure 5.14 Temperature distribution after the first cooling period ∙ Vertical section

10



Nr.2.3.


66

Figure 5.15 Temperature distribution after the first heating period ∙ Horizontal section

11



Nr.2.4.


67

Figure 5.16 Temperature distribution after the first heating period ∙ Vertical section

12



Nr.2.5.


68

Figure 5.17 Temperature distribution after the fifth cooling period ∙ Horizontal section

13



Nr.2.6.


69

Figure 5.18 Temperature distribution after the fifth cooling period ∙ Vertical section

14



Nr.2.7.


70

Figure 5.19 Temperature distribution after the fifth heating period ∙ Horizontal section

15



Nr.2.8.


71

Figure 5.20 Temperature distribution after the fifth heating period ∙ Vertical section

16

Figure 5.21 Spread of the temperature outside the building after summer and winter building

operation.17

Figure 5.21 shows the spatial temperature change of the ground in the nearest proximity of

the building in directions east and south. In the southern direction the change is slightly



Nr.2.9. 17 Professor Dr.-Ing Katzenbach, Dr.-Ing. Matthias Volger, Dipl.-Ing. Thomas Waberseck, Dipl.-Ing. Ulrich Adamietz, „Ergebnisse der FE-

Berechnung zur thermischen Beeinflussung des Untergrundes“. Ingenieursozietät Professor Dr.-Ing. Katzenbach GmbH, 16.02.2007, page

20.

Temperature

[°C]

Temperature

[°C]

The east edge of project area The south edge of project area


72

higher: first at the distance of 12,0 m from the building the temperature change comes to a

value of Δt < 1,0 K, while at a distance of 23,0 m, in the layer of Frankfurter clay, the

temperature rises again with approximately 1,0 K. Temperature finally falls at the distance of

37,0 m to the value Δt < 0,5 K. In the eastern direction, the final fall of the temperature

appears at a distance of 24,0 m from the construction.

5.3.6 Heat and cold demand

The yearly temperature oscillations have a strong effect on the heat gain and transfer under

the ground. Fig. 5.22 shows the average temperature change in Frankfurt am Main during

the whole year. July and August have a great opportunity to store heat in underground.

Figure 5.22 Yearly average temperature (°C) graph for Frankfurt am Main

18

In addition, building’s energy demand (for heating and cooling) depends on in general on the

following parameters:

Thickness and quality of isolation

Appearance of cold bridges

Compactness of the building volume

Air-tightness of the building (e.g. construction material for building envelope, the

wall thickness etc.)

Heating / cooling elements (surface heating / cooling is the least energy-

consuming but demands the highest investment costs)

Solar gains through the façade (depends on the orientation of the facade)

Possibility of glass shading

Inner heat gains (computers, machines, lightings, amount of people etc.)

Vertically open floors (warm air moving upwards)

The skyscraper PalaisQuartier complex is in many ways a reasonable compromise between

architectural features and energy saving issues. While the office and hotel towers are fairly

rational both in general composition and façade material palette, even with some

18 http://www.worldweatheronline.com/Frankfurt-weather-averages/Hessen/DE.aspx

http://www.worldweatheronline.com/Frankfurt-weather-averages/Hessen/DE.aspx


73

contemporary effects like tilted exterior walls, the shopping mall gives a rather striking

impression with its avant-garde roof surface which “melts” into the hole of the main façade

towards the shopping street Zeil. This daring structure enables natural light even until the

underground passageway, but on the other hand increases the glass façade surface into

shady canyons, which presumably contributes to higher energy consumption especially in

the winter. However, it also gives an opportunity for natural ventilation for example in the

sunny spring and autumn days that might otherwise overload the glazed passage with solar

heat. For this particular location, tightly surrounded by older department stores and other

commercial buildings within the same block, there is a good argument for maximizing the

daylight inside the complex with the help of memorable architecture.

The heat and cold demands are in details analyzed for different parts of PalaisQuartier

separately.

Heat and cold demand in PalaisThurn and Taxis

As a building with historic origin, the palace has thick walls, which are storing heat and cold

in the short term and thus balancing the natural daily variation of temperatures. However,

since the current house has been completely rebuilt, the load-bearing inner construction

being modern reinforced concrete, the heating and cooling demand can be evaluated

according to similar criteria as with modern buildings. The newly built Palace has also a large

hall for events, which is located under the courtyard (Cour d’honneur). There is a possibility

for appearance of cold bridges in the foundations, ground plates, intersections of façade and

floor plates and window frames.

Figure 5.22 Exterior wall renovation – PalaisThurn and Taxis19

Heat and cold demand in Nextower and Hotel Jumeirah

The energy concept of the towers envisages that about 50% of the heating/cooling energy

requirement is covered by sustainable systems. About 20% of the figure is obtained through

geothermal resource with a combined heat-pump and cooling system. The highly efficient

central heat recovery plant relies on radiant heat from the shopping mall and the

underground car park. It provides about 30% of the total heating energy requirement. The

19 http://www.deutsches-architektur-forum.de/pics//schmittchen/822palais_tt.jpg

http://www.deutsches-architektur-forum.de/pics/schmittchen/822palais_tt.jpg


74

rented areas are cooled or heated by means of a heating control system for the respective

building section integrated into the concrete ceilings. For this reason, there is no need for

suspended ceilings in the sections containing office workstations.

Ambient temperature, lighting and solar protection blinds are all centrally controlled by

sensors, which can be individually set at any time. There are integrated inner sunshades (in

the case of double glass façade the sunshade is put between the glass surfaces). Besides,

also ventilation through the windows can be used.

1) Technical data about the towers:

The temperature can be controlled manually per room and floor – thanks to

intelligent building automation

Combined chilled and heated ceilings

Cooling water is regulated using heat pumps and chillers and there is an ice

thermal storage for peak times

Internal heat load: 27 W/m2

External load generated by solar radiation: up to 60 W/m2

Cooling load depending on position of the room: 40–90 W/m2

Fresh air exchange: 60 m3 per hour/person

2) Façade materials and characteristics:

Single façade: Glass and aluminium with solar protection on the inside

Double façade: Aluminium

Highly transparent, uncoated glass exterior

Solar protection in the cavity

Insulating glass for thermal protection

Heat and cold demand in shopping mall MyZeil

The predominantly glass-topped shopping mall is supposed to work as a heat collector for

the whole PalaisQuartier complex. In addition, rainwater is collected from the nearly 6000 m2

roof area, being cleaned and used as gray water for the building. Heat energy sources

include the sun through the glass, machines, computers, lighting, and visitor crowds of the

shops and the garage of nearly 1400 cars. The multi-storey shopping arcade does not have

additional sunshades. During the opening hours, there is a constant airflow between indoor

and outdoor areas due to the moving crowds, which causes some energy losses especially

in the coldest but probably also in the hottest season.


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5.4 Brief introduction of other possible systems

Except the open system and closed system that have been introduced at the beginning, a

combined system is also a research emphasis in the geothermal energy utilization aiming

to increase the sustainable energy supply. There are potentially many combinations of

different systems to increase the energy efficiency of urban block and district. Aquifer thermal

energy storage – either as an open or closed system – can be used together with other

natural renewable energy sources that may cover the energy need of heat pumps etc. and

thus make the buildings more self-sufficient in energy.

For instance, photovoltaic panels are a rather easy option if they can be placed in a suitable

way, catching the sun and being protected from public trespassing. However, in the case of

PalaisQuartier (and many other architecturally remarkable building complex), the possibility

of placing photovoltaic panels is largely limited because most of the façade and roof surfaces

have been occupied by other functions; not to forget about aesthetics.

Wind energy can also work together with ATES, especially tall buildings have some potential

advantages in this respect. The challenge is the integration of wind turbine devices and

architecture (also structural engineering if the device is big), especially when the wind device

is to be installed afterwards. Depending on the size and geometry of wind devices, they may

create noise and inconvenience for the downtown and danger for birds.

It is also technically possible to go deeper into the subsurface with ATES systems: this would

help to gain more efficient geothermal energy supply. However, it is impossible to extend the

subsurface system afterwards in the case of energy piles, at least with current technology.

The other obstacle – at least in Germany – is the Mining Law that restricts underground

constructions deeper than 100m from the ground level.


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5.5 Analysis and evaluation

5.5.1 Potential for ATES

ATES is supposed to achieve a significant reduction of CO2 emissions. It is able to give a

return on investments in about 5-8 years, therefore its application in the EU is promising.

Since the Frankfurt region lies in the area of usable aquifers, its subsurface is highly suitable

for energy storage. In the densely urbanized city, it is almost impossible to realize other

sustainable options such as wind energy and biomass. Energy storage in the ground is

therefore most suitable in this case; it is invisible, noiseless and odorless. Since the high-rise

complex of PalaisQuartier needed deep foundations, no additional construction material was

needed to manufacture energy piles and no additional pollution was emitted during the

construction period.

In Germany, Frankfurt is considered to be the city of skyscrapers. This is confirmed by the

city’s master plan from 2008, so called Hochhaus Rahmen Plan or “general high-rise plan”.

The plan consists of proposed locations for 22 new high-rise buildings, where the primary

energy requirements must not exceed 150 kWh per square meter of gross area per year.

This stresses the importance of low energy building planning also for large building

complexes.

The effective use of the subsurface brings many benefits in the densely urbanized districts.

In the future, more effective use of ATES technologies must be promoted to avoid that every

individual is going to build a separate installation which could cause unwanted interactions

between the systems. This will allow the development of larger, more efficient energy storage

systems. Different urban “heat producers” (glazed public buildings, office buildings, data

centers, residual heat from industry) could be connected to each other in order to store heat

into subsurface for heat demanding buildings like residential blocks, schools, universities and

others. Also cooling of “heat producing” buildings during summer is very efficient through

ATES energy piles. Master plans of such interconnected systems should be planned in the

future. These would not only reduce the CO2 emissions but also promote more collaboration

and seeking for common goals inside the city communities. Furthermore, the use of

sustainable technology in large downtown public buildings should also be of national interest

in order to show sustainable building systems to large amount of visitors.

5.5.2 Feasibility (barriers to overcome, boundary conditions)

Technical feasibility

The site area is situated in the Frankfurt city center and at about 101,0 mNN and 102,0 m NN

above sea level. The zero level of the building was set at ± 0,00m = 101,65 mNN.

Out of a total of 302 foundation piles, were 262 used as energy piles. The upper edges of

this piles were below 5 level underground premises between 79,0mNN and 80 mNN, The

lower edges of the piles were according to the static stability demands between 53,2 MNN

and 70,1mNN. Out of the 543 shoring wall-piles approximately each second was used as

energy pile, together 130 piles. These shoring wall-piles are enclosing the construction site.

The upper edge is situated between 94,1mNN and 99,6mNN, the bottom edge is between


77

59,8mNN and 73,4mNN. The pipes for the heat/cold exchange were placed below the upper

edge of the piles in ground layer III-Frankfurt clay(Tertiary hydrobon layers) and layer IV-

Frankfurt limestone (tertiary inflate layers).

Financial feasibility

PalaisQuariter is a building complex with relatively large cooling and heating capacities.

Therefore, the economical boundary conditions are favorable. Because chillers are

practically avoided due to the direct cooling from energy piles, the additional investments for

aquifer storage are small while there is considerable saving on energy consumption.

Furthermore, the program of the building complex that is partly public (shopping mall) and

connected to a luxury hotel, contributes to investment decisions, which have included also

environmental aspects that promote the premises.

The PalaisQuartier construction was a financial success story. The shopping center brought,

since the opening five years ago, annual growth rates of 10 to 15 per cent of visitors. The

customer density is evaluated to 300 visitors per m2. Investment costs of the building

complex were approx. 960 Million Euro. It was built as mutual development of MAB

Development Group B.V. (owned by Rabobank) and Meyer Bergman Ltd.

There are at the moment no subsidies that would target financial support of ATES installation

in Germany. However, there are some possibilities to get financial aid within a building

construction or renovation plan or through programs supporting renewable energy. KfW bank

is offering low interest loans for components of renewable heating or construction of such

systems. In addition, pilot and test sites can be funded by various programs of the German

Federal Ministries.

Legal feasibility

A general rule is that permission is needed whenever the intrusion into the underground

reaches the groundwater level. This is stated on the federal level in the Water Household Act

(WHG, status 2009).

ATES is not allowed to bring about groundwater contamination in the proximity to

groundwater protection area, so far. However, in the case that geothermal energy is only

used for own energy supply of the property, there is no need of an allowance for the

exploitation (allowance according to the Federal Mining act). A geothermal power station,

which does not go deeper than 100m, only requires an approval of the Water Household Act

(WHG). This was the case of the PalaisQuartier construction process. A geothermal power

station can have influence on the neighbor’s property when the distance between the power

stations is small and the operation of the power station on the neighboring property remains

possible at all times. According to the VDI 4640 part 1 the minimum distance to the

neighboring property should be chosen as large as possible. It is recommended to maintain a

minimum distance of 10m to borehole heat exchangers on the neighbor’s properties.

Exceptions are possible if there is an agreement between neighbors. These distances

between boreholes of heat exchangers are not regulated by a general law, every federal

state has its own guidelines (distances range between 5 and 10m). In PalaisQuartier energy

piles were put also in the shoring walls. This means that they are laying directly on the border

to the neighbor’s property.


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A geothermal station has influence on the temperature and on the physical characteristics of

the groundwater. According to § WHG § 9 the thermal influence on groundwater through the

use of a geothermal station counts in the use of inshore waters for which permission

according to § WHG §8 is necessary. Especially in the areas of high population density, the

interference of geothermal constructions has to be analyzed. As described in § 5.3.5

temperature changes of the ground is expected in the nearest proximity of the building

advancing in the east and south direction of the PalaisQuartier building block. The

continuous observation of these effects and precise analyze of the results is of great

importance. It is also important that the most problematic thermal change of PalaisQuariter

zone appears in the southern area, where a broad pedestrian street Zeil is positioned.

However, it does not affect future development of the neighboring blocks.

The VDI 4640 includes different recommendations for maximum temperature and

temperature difference for heating and cooling of the heat carrier for closed systems. They

range between ± 11K for the weekly mean load and ±17K for the peak load. For open

systems a temperature difference of 6 K and a maximum temperature of 20 °C are

recommended.

Environmental effects and benefits

According to the modelling a moderate increase of temperature in the thermal characters of

ground is expected.

During the construction period no notable additional pollution was caused (compared to the

similar building complex without ATES) since the system was built within the foundation

piles. After the first five years of operation, according the model calculations, a slight overall

temperature increase in the thermal characters of the ground was induced and the thermally

influenced area has expanded in the direction corresponding to the underground water flow.

It is known that thermal energy is left behind in the subsurface of ATES operated buildings.

ATES systems are generally designed to work during the lifetime of the building (~30 to 50

years). When such sites are abandoned, it can take from hundreds to thousand years before

the temperatures of warm and cold groundwater left behind can completely disperse and

diffuse. To ensure sustainable use of subsurface, future ATES system must be able to

benefit from the energy stored in the subsurface. From this point of view, facilitating direct or

indirect communication between many different systems would result in the development of a

network of ATES systems instead of systems operating independently next to each other. 20

About 20% of heating and cooling energy demand of PalaisQuartier can be covered by

ATES system. It is noiseless, odorless and invisible.

5.5.3 Goals

The combination of geothermal heat exchangers and PVT (PV and Thermal) must lead to an

improved overall efficiency of the energy system. An essential part of this overall energy

efficiency improvement is to optimize the operation of the heat pump with regard to the

electricity and heat production of the PVT panels. The heat pump uses both heat and

20 Bloemendal, M., et al., “How to achieve optimal and sustainable use of the subsurface for Aquifer Thermal Energy Storage”, Energy

Policy (2013), http://dx.doi.org/10.1016/j.enpol.2013.11.034

http://dx.doi.org/10.1016/j.enpol.2013.11.034


79

electricity to provide heating (and if required cooling). Heat can be stored and retrieved from

the subsurface with the geothermal heat exchanger.

Because the modelling of energy piles in project area is still in progress, right now it is hard

to judge which system is most suitable for improving the energy efficiency for the future. All

the involved boundary conditions and stakeholders’ benefits and restrictions must be

considered with the further modelling information synthetically.

5.6 Conclusion

Out of all types of sustainable energy, the energy storage technology has the most favorable

economic characteristics. It’s payback time is only a few years compared to conventional

fuels. However, most of these benefits are available only for large and heterogeneous

buildings. PalaisQuartier is such a heterogeneous combination of high-rise, glass hall

(shopping mall) and multi-storey underground which has complementary heat and cold

demand, resulting in balanced annual heat and cold production in the aquifer.

In the future, instead of single building projects more district heating/cooling systems with

ATES technology should be planned. In this way, conflict areas of heat and cold volumes in

the subsurface could be prevented.

5.7 References

Dr.-Ing. Matthias Volger, Dipl.-Ing. Ulrich Adamietz, „Erläuterungsbericht zum

Antrag auf Erlaubnis zur Gewässerbenutzung durch Erdwärme- bzw.

Erdkältepumpen gem. §3 Abs. 2 Nr. 2 Wasserhaushaltsgesetz für

Erdwärmesonden (indirekte Grundwasserbenutzungsanlagen) mit einer Leistung

größer 30 KW“, Annex 1.1 – Overview city map. Ingenieursozietät Professor Dr.-

Ing. Katzenbach GmbH, 07.06.2004.

Professor Dr.-Ing Katzenbach, Dr.-Ing. Matthias Volger, Dipl.-Ing. Thomas

Waberseck, Dipl.-Ing. Ulrich Adamietz, „Erläuterungsbericht zur

Erdwärmenutzung“. Ingenieursozietät Professor Dr.-Ing. Katzenbach GmbH,

16.02.2007.

Professor Dr.-Ing Katzenbach, Dr.-Ing. Matthias Volger, Dipl.-Ing. Thomas

Waberseck, Dipl.-Ing. Ulrich Adamietz „Ergebnisse der FE-Berechnung zur

thermischen Beeinflussung des Untergrundes“. Ingenieursozietät Professor Dr.-

Ing. Katzenbach GmbH, 16.02.2007, layout.

Bloemendal, M., et al., “How to achieve optimal and sustainable use of the

subsurface for Aquifer Thermal Energy Storage”, Energy Policy (2013),


www.palaisquartier.de

http://www.palaisquartier.com/en/office-tower-nex-tower

http://www.palaisquartier.com/en/hotel-jumeirah

http://www.palaisquartier.com/en/shopping-centre-myzeil


http://www.deutsches-architektur-forum.de/pics//schmittchen/822palais_tt.jpg


http://www.palaisquartier.de/

http://www.palaisquartier.com/en/office-tower-nex-tower

http://www.palaisquartier.com/en/hotel-jumeirah

http://www.palaisquartier.com/en/shopping-centre-myzeil


http://www.deutsches-architektur-forum.de/pics/schmittchen/822palais_tt.jpg


80


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6 ITALIAN TEST SITE & PILOT DESIGN DESCRIPTION (D3-B)

6.1 Site characterisation and development plan “ex-Mercato Bestiame”

The site “ex-Mercato Bestiame” is in the NE part of Modena, Emilia-Romagna, Italy. It is a

residential area in partial redevelopment on a former livestock market area. The location of

the site is shown in figure 6.1.

Figure 6.1 Location of site

Currently, the site is partly used as a residential area. Neighboring sites have residential and

commercial uses. In figure 6.2, a recent aerial photograph illustrates the current use of the

site and its planned design after redevelopment.

The site is part of a larger redevelopment plan for the Northern part of the city. The gross

surface area of the site, which is depicted by the red boundaries on the right hand side of

figure 6.2, is 13.500 m2.

According to the municipal plans of Modena, the site should accommodate 600 living spaces

(presumably appartments and family houses) after redevelopment. The size the living spaces

is not clear, only a maximum of floors is given (6 stories). An average living space in Italy

consists of 4 rooms with a total floor space 80 m2 and a floor height of 3 m. Based on these

assumptions, a total floor space of 48,000 m2 will be used in this report.


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Figure 6.2: Current and future use of site “ex-Mercato Bestiame”

The gross floor index ratio, which is an

indication of urban density, will then be 3.5.

This indicates an intense use of the area for

buildings. Higher numbers generally favour

the design of more centralized heat (and cold)

production and distribution systems as the

costs of the distribution network will relatively

be low (less length per living space), see

figure 6.3.

Figure 6.3 Schematics of district heating system

6.2 Potential for ATES

The feasibility for an ATES system depends on one side on the demand side (the exergy,

energy and power of heat and cold) and on the other side on the supply side (physical

availability of aquifers and legislative boundary conditions to use groundwater).

6.2.1 Subsurface suitability

The area is situated in the Modena plain, at an average altitude of 33 m above sea level

(asl). The area is characterized by slow surface runoff and low energy depositional

mechanisms, as the main surface lithology is silty-clayey. The surface has a very modest

steepness (1-2‰). The area is located in within the central-southern portion of the Padan

basin, directly influenced by the Po river and its right bank tributaries. The total thickness of

the alluvial Pleistocenic and Holocenic depositional sequence is about 200-300 m (Fig. 6.4).

This complex, mostly a result of the river Secchia sedimentation, consists of a sequence of


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fine grained sediments with coarser levels hosting aquifers with significant thickness, and

with a decreasing thickness in Northwards direction (about 40 to 20%).

More detailed soil profile data are not available yet.

Figure 6.4: Simplified geological profile (WE).

From a hydrogeological point of view it is a multilevel aquifer, originating from the continuous

migration of the main river. At a regional scale the connected depositional lenses of coarse

material, which are hosting confined aquifers, form one single aquifer system. Considering

the predominant fine grainsize sediments, the first aquifer layer is confined, with a

groundwater table located between 3÷ 4 m bgl.

Until about -8/10 m clay and silts are present, subsequently a sequence of clay and silty-

sands, covering the first continuous coarse (gravel) layer, located between -17 and -30 m bgl

with a thickness between 7 and 13 m, consisting of gravels (ø max=10 cm) in a clayey/sandy

matrix. Below this layer, a mostly clayey level of about 20 m thickness covers the second

coarse layer.

In the shallowest levels small perched groundwater bodies not connected to the main aquifer

are present with limited circulation due to their geometry. The seasonal trends of these

surface aquifer bodies are connected to precipitation events, as rainwater is the main

recharge source. At the western side, sealed, runs a drainage channel NNE-SSW.

The groundwater temperature is expected to be about 14 °C.

For the application of ATES, these generic properties seem to be good or even very good.

The capacity of the aquifer is high as well as the expected infiltration and extraction rates.

6.2.2 Legislative suitability

From a legislative point of view, the use of the subsurface by ATES systems is limitedly

regulated. By law the delta T which can be used is 5°C. Main critical points in the Province of

Modena Water Protection Plan deal with surface water quality, the alteration of natural flow

regimes, the reduction of surface and groundwater quantities, and nitrate contamination in


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groundwater. Nitrates originate from fertilizers and from the use/treatment of manure, and

from the leakages of the wastewater treatment networks. It is not clear to what depth the

increased nitrate concentrations are found.

Main goals of the plan are the improvement of polluted water bodies, especially those with

defined uses, of which the drinking water use has priority, as well as the maintenance of

good quality habitats in wet areas (Provincia di Modena, Piano di Tutela delle Acque). Main

implemented activities have aimed at reducing the pollution sources.

At the site, in the past the large amount of groundwater withdrawals (70 ies – 90ies) for

drinking water uses has accelerated subsidence, but now these withdrawals have stopped,

subsidence is not an issue anymore. At present there are no wells used for drinking water in

the area. Other uses of groundwater are possible, provided they do not alter groundwater

flow significantly (Verifica di Assoggettabilità, Comune di Modena).

From legislative perspective there seems to be no major problems related to the installation

of ATES systems.

6.2.3 ATES opportunities

Based on available data, two main possibilities exist for ATES application in the site of

Modena:

Energy storage in combination with a heat pump

The site ex-mercato bestiame would be an interesting case to demonstrate the added value

of thermal energy storage in combination with a heat pump within a district heating network.

HERA (the utility company responsible to supply heat to the buildings) indicated that they

have some flexibility with the installation of innovative systems as longs as they can supply

sufficient heat at a temperature of 90 °C to the connected buildings. The ATES will perform

as heat source and possibly as heat storage. In order to obtain maximum reduction of CO2

emissions and minimizing the input of primary energy the design of the heat production

system needs careful consideration.

Energy storage and improvement of groundwater quality in combination with a heat

pump

Although there is no direct need to improve groundwater quality –especially looking at

nitrate- on the site itself, a groundwater quality improvement by the operation of the ATES

system would be very attractive to stimulate the further application of ATES systems in the

region. The hypothesized process that could (potentially) remove nitrate from groundwater is

the mobilization of organic carbon that might act as electron donor and carbon source to

allow denitrification in case that denitrifying bacteria are present. To make use of this

process, the infiltration/extraction wells of the ATES system needs to be located at the same

depth as the nitrate contamination.

6.2.3 Barriers for ATES

In this case there are two barriers which have to be overcome:


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Experience: the partners have limited experience in the design and operation of

ATES systems. The goal is to share experiences in order to design an effective

energy system that has lower GHG emissions at lower costs for the consumers.

Legislation: the aquifers in Modena are locally contaminated by nitrate. Although it is

not a real (legal) barrier, the ambition of the municipality is to improve the quality of

the aquifer. They look at non-conventional ways to improve the quality without too

much costs.

6.3 Energy demand and supply

Modena as municipality has defined ambitions in terms of energy and environment by

agreeing to the Covenant of Majors and thus sharing the EU 2020 targets (20% reduced

energy consumption, 20% share of renewable energy, 20% cut on CO2 emissions). Modena

has to comply also with the regional Energy Plan of Emilia-Romagna (approved in 2007)

which sets the goal of 55.000 TOE (tons of oil equivalent) of energy saved by 2015.

The city’s strategy to reach these objectives are described in the Sustainable Energy Action

Plan (SEAP) prepared in 2009. Modena’s CO2 emissions amounted to more than 1x106 ton

of CO2 for the entire city, and to 5.76 ton CO2 per citizen per year. The aim is to reduce the

overall emissions by 220.400 ton CO2. The strategy includes actions in the fields of energy

production (decentralized energy production and solar energy), energy efficiency, transport,

and education.

The development of an area for residential use will in most cases lead to an increase of the

cities energy use and thus to an increase of CO2 emission. Only when zero energy houses

are built the net increase of CO2 emission will not change.

6.3.1 Heat & cold demand

Heat and cold demand for temperature conditioning of buildings depend on local climate

conditions, the preferred indoor temperature, and on the buildings physical design, including

the level of insulation (thermal resistance) and the use of passive solar heat. Heat demand

for hot tap water depends on the average use of hot tap water, which is mostly related to the

number of inhabitants per living space, and the presence of showers, bath, and hot fill

equipment. Temperature of hot tap water is generally > 60°C to prevent Legionella

contamination.

Local climate conditions are depicted in figure 6.5. Based on the average monthly

temperatures it can be deduced that in summer time some cooling is appreciated to regulate

indoor temperature. In winter time heating is required.


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Figure 6.5: Average high and low temperature in Modena (source: worldweatheronline.com)

Currently, the buildings physical properties are not known. Based on expert judgement

(Dutch situation), a proper insulated, modern house requires limited heating power (appx 25

W / m2). For 600 living spaces with an average floor space of 80 m2 the total (gross) power

demand will be 1.2 MWthermal. Hot tap water however, requires a considerably higher heating

power of about 20 kW/living space. For 600 living spaces this adds up to 12 MWthermal. The

total power demand, including space heating and hot tap water, will thus be 13.2 MW thermal.

A major advantage (energetically) for any centralized heat production facility is a reduced

chance that all customers require the full heating power simultaneously. Installed power can

therefore be reduced. In this case Hera estimated a simultaneous factor of 70% is applicable,

leading to a (maximum, total) power demand of 9.2 MW thermal. A disadvantage however are

heat losses during the transport of heat from the boiler room to the consumers. An estimated

heat loss of 12% leads to increased power demand of 10.3 MWthermal to be produced in the

boiler room.

The required power for cold supply is not estimated. Comparing these estimates with the

data provided by Hera is not yet feasible as the number of existing living areas is unknown.

In order to better value the possible advantages of the ATES system however, a rough

estimation of energy requirement for cooling is provided. For Italy, an average cooling

demand was reported to be 50 kWh/m2/year (final report Work Package 2 Ecoheatcold

project, 2006) leading to a cold demand of 2400 MWhcold. Assuming 500 cooling load hours,

the power demand for cooling will be 4.8 MWcold.

6.3.1 Heat & cold supply

To provide sufficient power for heating the buildings and to provide hot tap water, while

minimizing the installation costs, power losses in the distribution network and the

simultaneous heat demand needs to be estimated. To estimate the possibly existing

advantages of ATES to supply heat and cold 4 scenarios are explored that differ between

organization (centralized vs semi-centralized) and technology (low, medium, and high

temperature distribution and individual or distributed cold supply). The scenario with

centralized, high temperature supply is used as reference scenario. The 3 alternative

scenarios will be compared to this reference scenario in terms of primary energy

consumption, CO2 emission, and energy costs.


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Centralized high-temperature-heat supply (reference)

In this scenario, water (as carrier for heat) is heated in the boiler room to 90 °C (see 1 in

figure 6.6). In the boiler room a suite of technologies can be located with the sole function to

heat up the water. The efficiency of the boiler room depends both on the chosen technology

and the required temperature (actually power). In the proposal of Hera, the following

technologies are put forward to produce hot water.

Table 6.1 heat generation in the boiler room

Technology Proposed power full load hours / year fuel efficiency

Existing gas-fired boilers 1.5 MWthermal 3000 (estimation) ηth = 75%

New power/heat cogeneration

0.8 MWthermal 3000 ηth = 50%, ηel = 35%

Compressed natural gas boiler 1

2.5 MWthermal 1600 ηth = 85%

Compressed natural gas boiler 2

4.0 MWthermal 1000 ηth = 85%

Heat pump 0.6 MWthermal 3000 COPheat = 2.11

Thermal solar 0.1 MWthermal 2000 COP = NA

Total 9.5 MWthermal 1800 (average)

1 assuming Thigh = 100°C, Tlow = 12°C and Carnot efficiency = 0.5

The proposed power in table 6.1 is lower than the maximum power calculated in § 6.2.1. but

it should be noted that the calculated power was based on generic, not site-specific,

information.

http://www.google.nl/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=FX8Km3eKEAx5YM&tbnid=KVfGkrxWyMqaWM:&ved=0CAUQjRw&url=http://en.smartheatgroup.com/solution/Districtheating/index.html&ei=lPH0UrjbHMmH0AWIooDoDQ&bvm=bv.60799247,d.d2k&psig=AFQjCNFZwnsFvsAheQ0ErSpaN5gKEQmfmQ&ust=1391870723762731


88

Figure 6.6 Schematic of scenario with centralized, high temperature supply of heat (taken form

http://en.smartheatgroup.com)

From the boiler room, hot water (90 °C) is transported to the heat consumers (see 2 in figure

6.6). Heat losses depend on the travelled distance and the insulation level of the heat

distribution network. According to the information provided by Hera, heat losses are expected

to be 12%. A continuous flow of hot water is needed to supply hot water to the apartments at

a reasonable delay. The energy use for pumping (electricity) is not known but is generally

assumed to be about 1% of the energy that is delivered. The number of connected

apartments (and perhaps other heat consumers) influences the chance that all consumers

require maximum heating capacity, especially regarding hot tap water. The more consumers

connected to the distribution network, the lower the chance that all consumers demand heat.

This is reflected by the simultaneous factor which is estimated to be 70% by Hera.

At the apartment level, a heat exchanger is installed to separate the water flows of the main

heat distribution network and the heat distribution system within the apartment (see 4 in

figure 6.6). Although the temperature level of the heat distribution network is targeted to be

90 °C, the temperature of the apartment heat systems can be lower. The optimal

temperature depends on the insulation level of the apartment (heat power losses due to

conductivity through walls, floor, roof, and windows) and the way of ventilation (see

paragraph 6.2.1). The advantage of constructing well insulated apartments and installing low

temperature heating systems is the flexibility to change the district heating system into a

lower temperature system without reconstructing the apartments.

Based on the data shown in table 6.1, the primary energy consumption for heating will be

21.1 GWh of which 0.9 GWh is electricity. The heat that will be delivered to the apartments

totals 14,900 MWh after subtracting the heat losses. The CO2 emission is calculated to be

4.45 kton, using an emission factor of 201.6 kg CO2/MWh gas and 435 kg CO2/MWh

electricity. Based on energy prices (€ 0.042 per kWh gas and € 0.168 per kWh electricity;

data from Eurostat 2013 category industry) the energy costs are k€ 993 per year.

For the supply of cooling it is assumed that an air-conditioning unit (energy efficiency ratio of

3.23 (topten.eu room air conditioners, 2012)) will be installed in each apartment. To supply

2400 MWhcold cooling energy, an electricity consumption of 740 MWh is expected. CO2

emission will be 322 tons and costs are estimated to be k€ 170 per year (€ 0.229 per kWh

electricity; data Eurostat 2013 category households).

The performance of the heat pump in combination with aquifer energy storage is not optimal.

Using the estimated Coefficient of performance of 2.1 it can be shown that a production of

0.6 MWthermal requires an electric power input of 0.29 MWe. For 3000 full load hours,

electricity consumption will be 857 MWh and CO2 emission equals 373 tons. The costs of

electricity (€ 0.168 per kWh electricity) will be 144 k€ per year. A modern gas-fired boiler

(thermal efficiency 85%) will consume about 238,000 m3 natural gas per year which leads to

427 tons of CO2 emitted yearly. The costs of gas (€ 0.042 per kWh gas) will be 89 k€ per

year. Furthermore, the produced cold (940 MWh) will not be used.

Groundwater flow to provide ambient heat to the heat pump needs to deliver 0.31 MW thermal.

Assuming a maximum temperature difference of 5°C (max. legal difference), a water flow of

~50 m3/h is needed to provide sufficient power.

http://en.smartheatgroup.com/


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The results for this scenario are summarized in table 6.2.

Table 6.2 Reference scenario

Heating:

primary energy consumption 21.1 GWh / year

CO2 emission 4.45 kton CO2 / year

costs of energy 993 k€ / year

Cooling:




Total:



Semi-Centralized medium-temperature-heat supply

In this scenario, water (as carrier for heat) is heated in the boiler room to 65 °C by a central

heat pump. In contrast to the previous scenario, the boiler room will only serve the

apartments on ex-mercato bestiame.

Distribution losses will be reduced compared to the high temperature distribution (assuming

8% energy losses) while the simultaneous factor remains 70%. For the rest, a similar

configuration is assumed as in the reference scenario.

The fuel efficiency of the heat pump (COPheat) will increase from 2.1 to 3.3 as the hot

reservoir will be 65°C and the carnot efficiency can increase to 0.55. For a total power output

(heat) of 9.1 MWthermal (including lower distribution losses and excluding 0.1 MW thermal

solar production) and assuming 1800 full load hours per year (same as the reference

scenario) the primary energy demand will be 5 GWh electricity. The heat that will be

delivered to the apartments totals 15 GWh after subtracting the heat losses. The CO2

emission is calculated to be 2.16 kton, using an emission factor of 435 kg CO2/MWh

electricity. Based on energy prices (€ 0.168 per kWh electricity; data from Eurostat 2013

category industry) the energy costs are k€ 833 per year.

For cooling the reference scenario remains unchanged.

A modern gas-fired boiler (thermal efficiency 88%) will consume about 2.1 Mm3 natural gas

per year which leads to 3.75 ktons of CO2 emitted yearly. The costs of gas (€ 0.042 per kWh

gas) will be 781 k€ per year. Furthermore, the produced cold (11400 MWh) will not be used.




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~1100 m3/h is needed to provide sufficient heating power. As no hydrological properties are

available, no estimation can be made regarding the dimensioning of infiltration and extraction

wells.


Table 6.3 Semi-Centralized medium-temperature-heat supply

Heating:




Cooling:




Total:



Semi-Centralized medium-temperature-heat and cold supply

In addition to the semi-centralized medium-temperature-heat supply, also cold is distributed

to the apartments. In order to distribute cold, an additional network is required leading to a

total of 4 distribution pipes between boiler room and consumers. Furthermore at the

apartment level, an installation to subtract heat from the apartment needs to be available,

such as floor or wall cooling. This installation can in principle also be used to deliver heat at

lower temperatures.

For heating, the previous scenario Semi-Centralized medium-temperature-heat supply

remains unchanged.

For cooling it is assumed that natural cooling can be applied using the reduced water

temperature of the cold aquifer storage without the installation of heat pumps as cooling

machines. The available cold (11.4 GWh, see paragraph 2.2.2.) is more than sufficient to

supply the cold demand. Advantage of using (part of) the stored cold groundwater is a

regeneration of the warm well. Besides the energy to extract and reinfiltrate the groundwater

in the ATES system and the distribution of cold water between boiler room and apartments,

no energy for cooling is needed.



~1100 m3/h is needed to provide sufficient heating power. As no hydrological properties are


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available, no estimation can be made regarding the dimensioning of infiltration and extraction

wells.


Table 6.4 Semi-Centralized medium-temperature-heat and cold supply

Heating:




Cooling:

primary energy consumption - GWh / year

CO2 emission - kton CO2 / year

costs of energy - k€ / year

Total:



Decentralized low-temperature-heat and cold supply

In contrast to the previous scenarios, this scenario will not have a central boiler room. Low

temperature water (~ 14 °C) and cold water (~ 8 °C) will be distributed between the heat

exchanger that exchanges heat or cold from the ATES system towards the distribution

network and the apartments with a 4 piped network. At apartment or block level a heat pump

will be installed to provide domestic hot tap water (65°C) and heat for space heating (35°C).

Several configurations are possible, to produce these flows with different temperatures

including a combination of a heat pump and an electric or gas boiler or solar thermal

collection. For simplicity 2 heat pumps will be used to either deliver heat for space heating

(heating power of 2 kWthermal having a COPthermal of 6.0 with 2000 full load hours) or heat for

domestic hot tapwater (heating power of 20 kWthermal having a COPthermal of 3.3 with 200 full

load hours). As only a limited amount of users are connected to the heat pump, no

simultaneous factor can be applied.

The primary energy consumption (electricity) for the heat pumps of 600 apartments will be

1.1 GWh per year leading to a CO2 emission of 0.5 kton CO2 per year. The electricity costs

will be k€ 258 per year (€ 0.229 per kWh electricity; data Eurostat 2013 category

households).

Groundwater flow can use the simultaneous factor of 70% as all 600 living spaces are

supplied. To provide sufficient ambient heat to the heat pump groundwater flow needs to


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deliver 6.6 MWthermal. Assuming a maximum temperature difference of 5°C (max. legal

difference), a water flow of ~1150 m3/h is needed to provide sufficient heating power. As no

hydrological properties are available, no estimation can be made regarding the dimensioning

of infiltration and extraction wells.


Table 6.5 Decentralized low-temperature-heat and cold supply

Heating:




Cooling:

primary energy consumption - GWh / year

CO2 emission - kton CO2 / year

costs of energy - k€ / year

Total:



6.4 ATES scenario evaluation

From the subsurface part, no problems are expected that hamper the use of ATES at the site

“ex-Mercato Bestiame”. Depending on the presence of nitrate in the aquifers, a combination

where energy storage might be combined with the removal of nitrate might be interesting.

Several technologies exist that can remove nitrates (if needed) from the aqueous phase,

such as ion exchange, reversed osmoses, biological denitrification, etc. The challenge would

be to select a technology that removes the nitrate while preventing large changes in redox

chemistry that might lead to well-clogging or increased corrosion.

However, from the demand side the integration of ATES (combined with heat pumps) is less

obvious. The connection between the new living spaces on the site with the existing heat

distribution system limits the environmental benefits due to the high temperature that is

required for the existing buildings. Only when lower distribution temperatures are allowed, for

example by uncoupling the distribution systems, to distribute heat the use of heat pumps is

advisable. An alternative might be the storage and distribution of cold that may be produced

in winter time. This would require additional infrastructure. Benefits are the avoidance of

(standard, not efficient) air conditioners and a reduction of electricity consumption (at high

powers) in summer time.

It is clear that the reference scenario is not the best scenario en terms of primary energy

demand, CO2 emission and energy costs. Especially the heat pump is underperforming due


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to the high temperature level that should be reached. Besides, without infrastructure to

distribute (and sell) the cold, the continuous extraction of heat from the aquifer will even lead

to lower efficiencies. Distributing cold will also have a positive impact on the CO2 emission

(which is reduced considerably) and energy costs, especially as no active cooling is needed.

Reducing the distribution temperature will largely increase the efficiency of the heat pump.

However this requires an uncoupling of the (new) heat distribution network with the existing

one.

In contrast to the improved energy efficiencies and reduced energy costs of the 3rd and 4th

scenario, it can be expected that investment costs will strongly increase as more expensive

heat production units (the heat pumps) will be needed and because a second distribution

network to distribute cold is required. Without proper estimation of investment costs it can

currently not be demonstrated what the overall economic advantage of the ATES system in

combination with heat pumps will be.

Furthermore, the role of Hera as supplier of heat will change considerably in the 4th scenario

as individual heat pumps and probably alternative heating units will be installed.

Organisationally, several concepts can be thought of, related to the ownership of the

individual heat pumps, the management/service of them, etc.

Utility company HERA indicates that they have some flexibility with the installation of

innovative systems as longs as they can supply sufficient heat at a temperature of 90 °C to

the connected buildings. Furthermore, HERA states that the distribution of cold does not fit

their business ambitions yet. As a consequence, the ATES will perform as heat source and

possibly as heat storage.

In order to obtain maximum reduction of CO2 emissions and minimizing the input of primary

energy the design of the heat production system needs careful consideration. In that context,

the best scenario is to the heat pump/ATES to preheat return flows to the gas boilers with

ATES and to combine the power/heat cogeneration system with the electricity needs of the

heat pump.

In this scenario, water (as carrier for heat) is preheated by the heat pump (using heat from

the aquifer) to 80 °C and further heated in the boiler room to 90 °C. This improves the heat

pumps efficiency to a COP of 2.7 compared to 2.1 in the reference scenario; see table 6.6.

Table 6.6 Energy costs for Scenario with preheating

Heating:

Primary energy consumption 20.9 GWh / year


Costs of energy 960 k€ / year

6.5 Conclusion

The new residential area that will emerge on the location “ex-Mercato Bestiame” has a high

potential for the use of ATES. The expected housing density and the total number of living


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spaces are sufficiently high to support a semi-centralised system that uses an open ATES

system in combination with a centrally operated or individual heat pumps.

The subsurface, both from a physical and a legislative point of view, seems to be well suited

to install an open ATES system. Depending on the presence of nitrate in the aquifer that

ideally will be used for energy storage and the ambition of the municipality or region to

remediate the contamination, a combination of ATES and remediation is interesting.

The use of aquifer thermal energy storage in combination with a heat pump delivers a

(maximum) yearly saving of 100k€ for energy costs beared by HERA. This impacts on

energy costs for HERA to provide the required heat to the buildings in the ex-Mercato

Bestiame area.

In addition to financial gain, the model of “retrofitting” of existing district heating networks by

means of ATES system could be applied to other areas in Emilia-Romagna. The improved

environmental sustainability of the neighbourhood can as well increase the value of the

urban area.


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7 SPANISH TEST SITE & PILOT DESIGN DESCRIPTION (D3-C)

7.1 Introduction

7.1.1 Location and facilities

The Spanish case situation is located in Almazora Village. Almazora is a little town placed 3

km at the south of Plana de la Castellón in the Valencia Region, see figure 7.1. In Almazora

there is a municipal pool. This pool, including a sports center, is a facility for more than

25,000 people using different services:

1. a 12.5 x 25m, Indoor pool.

2. a Learning pool 8 x12,5m.

3. Welness: Jacuzzi, Sauna, Steam room.

4. Gym.

5. Locker rooms.

6. Administration area, Service facility area’s, etc.

The facilities takes up 2.576 m2 that must be conditioned for the different activities mentioned

above.

Figure 7.1. Situation of Almazora.

7.1.2 Barriers to overcome and goals

In this case there are two barriers which have to be overcome:

- Quality / chain of delivery. There are many different patterns of heating and cooling

demand in one building. It is the challenge to make an integrated design, with all

parties involved to assure optimal operation after installation. An extra challenge that

a new type of geothermal well is used, so it\ behavior and dynamics are not yet well

known/understood. This makes an extra challenge to deal with.

- Legislation. It is allowed to make ATES-systems in Spain, but groundwater that is

pumped to surface level is regarded as waste water according to Spanish Law. So

getting permission to re-inject water is hardly possible and discharging used water in

a sewer also comes with additional conditions.


96

7.1.3 The Spanish partners

For the Spanish pilot, a consortium is already established:

- AIDICO, as member of the Valencia RIC and RTD and partner of E-USE (aq) project;

- ITECON, as SME who set up a new system to superficial Aquifer Thermal Energy

Storage (ATES);

- Almazora City Hall, who give the pool to implement the system.

7.2 Site description

7.2.1 Plan of the surroundings

The “Plana de Castellón” is a natural geographic region that covers a 464 km2 coastal strip

between Benicassim and Almenara, figure 7.2. The topography is a plain with small

elevations and surface level varies between sea level and +130 m.s.l.

Figure 7.2 Plana de Castellon, Almazora is the red dot

Almazora is located at the banks of the Mijares river, a few kilometers upstream of the river

mouth; see figure 7.3. The altitude of Almazora is +31 m.s.l. The area identified to implement

the system is located in the middle of the town, in an urbanized area. The economy of

Almazora is mainly based on agriculture and industry of ceramic pavement and floor tiles.

There are no soil contaminations recognized in that area.


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Figure 7.3 Surroundings of Almazora

7.2.2 Geology and hydrogeological conditions

Geology

The general geology can be described in four main formations, as shown in figure 7.4.

The Plio-Quaternary sediments are:

- Alluvial mantles crusted: from level +100 m.s.l. to +30 à +40 m.a.s.l. Conglomerate by

rounded stones of limestone and sandstone in clay matrix. This is the Quaternary

base;

- Piedmont deposits: is a heterometric gap and ‘polimicrítica’ with a size of the rounded

stones between 5-15 cm inside a clay or red sands matrix, surrounding the

preexisting reliefs;

- Mantles gully: are laminar deposits over alluvial mantles. The composition is red clay

with rounded stones.

Figure 7.4 Geological Scheme of Almazora area

Around the Mijares river:

A study in this area has helped to define different levels of subsurface composition:

- Level 1: composed by gravels and conglomerates

- Level 2: by gravels in clay matrix

Citrus Crops

River Mijares

River Mouth


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- Level 3: saturated level, where there are 2 sublevels, the upper with gravels and the

lower with gravels and sands.

The substrate is composed of Miocene clays

Hydrogeology

The area is supported by the Aquifer of La Plana de Castellón. This is a typical multilayer

aquifer. The main aquifer is constituted by Plio-Quaternary sediments, with packs of gravels,

sand and conglomerate immersed in a silt-clay matrix. This aquifer is laid over Mesozoic

materials (this is another aquifer) in some places in other cases over Tertiary materials

(figure 7.5).

The Aquifer thickness varies between 50-200m; the largest thickness is found around the

Mijares River, close to 200 m. The hydraulic head in the aquifer is between +10 m.s.l. and

sea level. The groundwater flow has a direction WNW-ESE (from interior to sea). The aquifer

has to deal with seawater intrusion in the part close to the coastal line. The main use of the

fresh groundwater in the interior of the area is for urban and agricultural use.

Figure 7.5. Aquifer of the Plana de Castellón


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7.2.3 Energy installations

Current energy facilities

Almazora swimming pool has installed the following facilities to supply for heating and

cooling:

- 2 gas boilers 186 kW each, fifteen year old, with a performance of 0.74,

- 1 dehumidifier system, currently out of order,

- Several split equipment to cooling rooms and other facilities.

These type of facilities use a fossil fuel to produce the thermal energy required. The

combination of the pool’s water temperature standard, needed air conditions, other specific

functions in the building and the poor performance of these facilities make that there is a

large potential for saving energy. Already the dehumidifier system is not used due to the

high running cost. This is leading to a significant deterioration of the buildings construction.

Next to that it is also considered to restrict the use of the other facilities during particular

periods.

The public owner of the facility is looking for some spare parts of splits and boilers to keep

them running. But since these machines are out of date they are planning to replace the gas

boilers by new but similar equipment.

See figures 7.6 and 7.6 for yearly development of energy demand on the site

Figure 7.6 Energy demand (Kwh) of heating and cooling in 2012 (blue = heating demand, red =

cooling demand)


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Figure 7.7 Cumulative energy demand (Kwh) heating and cooling in 2012

7.3 Feasibility check

7.3.1 Technical feasibility

The energy demand of the facility will not change significantly. With a new energy system it is

expected/required to reduce over 60% primary energy use and therefore CO2 emissions. The

proposed solution consists of a geothermal heat pump that takes advantage of the possibility

to simultaneously deliver both heating and cooling. Heating for the pool and sanitary water,

and cooling to the air handling unit, the gym and common areas, figure 7.8.

Figure 7.8 Configuration of new installation with Geothermal Heat Pumps

HOT SANITARY WATER NEW DCL

GEOEXCHANGER

NEW

GEOTHERMAL

HEAT PUMP

GYM CONDITIONING

DEHUMIDIFIER

POOL HEATING 28ºC


101

Energy and power demand

The total energy demand is depicted in the sankey diagram in figure 7.9. The total energy

demand for heating and cooling is respectively 565 and 240 MWh.

Figure 7.9 Shankey heating and cooling demand

Design and functional description of geoexchanger

The working principle of the geoexchanger is depicted in figure 7.10. A closed loop heat

exchanger is installed in a bigger tube in such a way tan water can flow along freely. With a

little pump groundwater is redirected to the installation in order to improve heat transfer. The

water pump of each geoexchanger will be situated some three meters under the low end of

the exchanger. It sends the water inside the main pipe up to the upper end.

The water is prevented from coming back to the bottom of the well by putting a thoroidal

elastomeric piece that closes the way down. As the well sheath has holes on it, water can get

through these holes and be absorbed by the surrounding soil, then infiltrating downwards to

the water table. This way, the heat exchange tridimensional volume is boosted, further than

the theorical slim cylinder of conventional systems, like a wide cone shape over the water

table.

The required power for heating from the subsurface is 88kW. With an expected specific heat

exchange capacity of 360 W/m, 290m of Geoexchanger must be installed to meet this

heating power. The effective length of one Geoexchanger is approximately 30 m.


102

Figure 7.10 Principle of geoexchanger

7.3.2 Financial feasibility

Costs of the innovative installation were compared to the current facilities, as specified over

the year in tables 7.1 and 7.2. All information, assumptions and calculations are provided by

project partner Itecon.


103

Table 7.1 Current natural gas usage

MONTH KW·h TOTAL €

1 97,027 5.422,21

2 123,055 6.991,35

3 60,938 3.512,10

4 78,419 4.620,25

5 55,872 2,872.15

6 18,650 1,205.24

7 10,057 704.61

8 9,057 645.34

9 19,382 1,295.39

10 53,041 3,351.24

11 64,461 4.047.24

12 65,578 4,115.54

YEARLY 655,537 38,782.66

Table 7.2 Current electricity usage

MONTH TOTAL KW·H TOTAL F €

1 33,163 5,051.72

2 34,900 5,384.71

3 31,775 4,896.06

4 33,558 4,354.51

5 32,478 4,324.12

6 30,692 5,444.15

7 40,008 6,320.25

8 39,092 6,341.66

9 25,388 4,326.15

10 30,652 5,301.97

11 30,619 6,130.34

12 32,290 5,945.11

YEARLY 394,615 63,820.75

It is expected that the geothermal system can replace around 40% of the current electric

energy use and 100% of the natural gas demand, resulting in avoided cost of:

€ 38,782.66 + 0.4 x € 63,820.75 = € 64,310,96


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For the installation of the new system, estimated costs are:

Machinery, heat pumpas and valves € 37,265

Piping: € 31,869

Wells, geotechnical tests and pump € 7,870

Electrical system & control € 3,924

Technical projects and supervision € 6,450

This results in total estimated investment costs of € 87,378.-

For the new installation, a conservative coefficient of performance (COP) of 5.96 is assumed.

For each kWh of heat and cold combined a consumption of 0.167 kWh in the thermal plant is

considered. This includes power consumption of pumps and ventilation. Based on this, an

overall COP of 5.4 (90% of the above) is assumed, in order to exclude periods without

simultaneous heating and cooling demands. Based on this COP, expected additional annual

energy costs were calculated for the new situation.

Table 7.3 Calculated additional energy use in new situation with geothermal installation

kWh

COP Combinated

kW·h ELEC Energy price

Expenses

JANUARY 77.621,60 5,4 14.374,37 0,139 1.991,59 €

FEBRUARY 98.444,00 5,4 18.230,37 0,139 2.525,84 €

MARCH 48.750,40 5,4 9.027,85 0,139 1.250,82 €

APRIL 62.735,20 5,4 11.617,63 0,139 1.609,64 €

MAY 44.697,60 5,4 8.277,33 0,139 1.146,83 €

JUNE 17.189,20 5,4 3.183,19 0,139 441,03 €

JULY 22.404,48 5,4 4.148,98 0,139 574,85 €

AUGUST 21.891,52 5,4 4.053,99 0,139 561,68 €

SEPTEMBER 15.505,60 5,4 2.871,41 0,139 397,84 €

OCTOBER 42.432,80 5,4 7.857,93 0,139 1.088,72 €

NOVEMBER 51.568,80 5,4 9.549,78 0,139 1.323,13 €

DECEMBER 52.462,40 5,4 9.715,26 0,139 1.346,06 €

TOTAL 555.703,60

102.908,07

14.258,03 €

To this, fixed power cost are added and more consumption of the system due to transport as

well as maintenance, respectively:

€ 14,258.03 + € 740.- + € 2.309 + € 1,200= € 18,507.03

Resulting in the total expected additional maintenance costs per year.

So the net avoided costs are € 64,310,96 - € 18,507.03 = € 45,803.93

Therefore, the investment will already be returned in less than two years:

€ 87,378.- / € 45,803.93 = 1,91


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Of course this does not include the development of the innovative technology.

7.3.3 Legal feasibility

Since no groundwater is extracted from the subsurface no permit is required for the

installation and exploitation this type of geothermal energy infrastructure. Consortium

partners already received affirmative answers from local and national environmental

administrations.

7.4 Conclusion

For overcoming the legal barrier in Spain that restricts the re-infiltration of water, an

innovative technical solution is found: the geoexchanger. This device uses separate loops

and groundwater stays in the soil. The difference with conventional closed loop systems is

that groundwater is pumped up actively above the ground water table, thus increasing the

efficiency of energy transfer considerably.


106

8 BELGIAN TEST SITE & PILOT DESIGN DESCRIPTION (D3-D)

8.1 Introduction

The case is about a distribution facility which is located between the cities of Antwerp and

Hasselt, figure 8.1. The facility processes sports goods from overseas to local customers or

shops and is partly manned and partly fully automatic.

Figure 8.1 Site location

8.1.1 Location and facilities

The distribution facility is in Flanders close to the city of Tessenderlo, located between high

way A13 and the Albert Channel. The facility is a distribution center which is partly manned

(low bay) and partly fully automatic (high bay), figure 8.2. The manned area has a large

heating demand, while the unmanned area has high internal heat production. There is also a

small utility building with restaurant, changing rooms etc. As a result from this design the

whole facility has a very small cooling demand relative to the heating demand, making the

applicability of an ATES system less optimal.

Figure 8.2 Site map


107

8.1.2 Barriers to overcome and goals

The economic/financial barrier is that it is not profitable to store a lot of the available heat in

summer without having the economic benefit of cooling as well. In Belgium it is not required

to have an energy balance in ATES systems. So to overcome the financial barrier it is

required to make a design for an ATES system that can sustainably deal with a cooling

capacity surplus without jeopardizing the ATES-systems long term performance.

This can be done in two ways:

1. Dumping heat in the aquifer without disturbing the longterm performance of the ATES

system

2. Collecting heat during surplus periods and temporarily storing this energy in the

aquifer.

8.1.3 The partners in Belgium Case

Also for the Belgium site, a consortium was erected:

- Consultant company Arcadis Belgium;

- Contributor of specific innovation Naked Energy;

- Site owner Nike.

8.2 Detailed site description

8.2.1 Geohydrological conditions

The geological composition in at the location consists mostly of fine sands sometimes

containing clay (Diest/Eigenbilzen formations). At about 100 m below surface level begins a

thick clay layer (Boom formation). The soil composition is schematized in table 8.1.

Table 8.1 Schematic overview of soil composition

[bore logs: kb25-BTH147, kb25-BTH142, kb25-BKE14]

depth Material

0-1 Humus, anthropogenic influenced material

1-5 Fine sand and solid clay

5-65 Medium - fine sand, with sandstone layers, clay

65-100 Fine sand, with sandstone layers, clay

100-140 Clay

Pumping tests have shown that the horizontal conductivity factor in the Diest/Egenbilzen

formation is about 12 m/d. The groundwater is fresh and the flow direction is West-South-

West. The slope of the groundwater head is hard to determine because the facility is at the

edge of a stagnant zone where the flow direction changes, as can be seen in figure 8.3. The

slope is around 2*10-3. For the location of the facility this results in a groundwater flow of

around 35 m/year. Because of this medium groundwater flow, both the recirculation and the

storage and recovery should be possible.

It is estimated that in the aquifer above the Boom formation it is possible to find at least 25 m

of suitable aquifer to install a filter screen and in best case 50m.


108

Figure 8.3 Areal groundwater isohyps pattern

8.2.2 Energy demand of the facility

The high bay (unmanned area) will be heated until 12°C in winter and cooled with natural

ventilation, because of the minimal climatic requirements, there is hardly any energy

demand.

In the low bay area people will be working, so climatic requirements are higher. This part of

the facility has mainly a heating demand.

The required power and energy for heating and cooling are given in table 8.2.

Table 8.2 Yearly power and energy demand from subsurface.

8.3 Feasibility check

8.3.1 Technical feasibility

Making an ATES system that can sustainably deal with a cooling capacity surplus without

jeopardizing the ATES-systems long term performance can be done in two ways:

Heating demand Cooling demand

430 kW Power 430 kW

690 MWh Energy 382 MWh


109

1. With a special type of ATES and using the natural groundwater flow, a so called

recirculation system, figure 8.4

2. A traditional ATES system with an additional facility to harvest heat in summer and

store it in the subsurface

a. Normal solar panels, only collecting heat

b. PVT solar panels collecting heat and producing electricity

Both will be elaborated in this study.

Figure 8.4 Recirculation system

Alternative 1 Recirculation system

With a recirculation-system, groundwater with natural temperature is used for both heating

and cooling. Short-circuit flow between infiltration and extraction wells must be prevented.

This can be achieved by placing the infiltration wells downstream and far enough away from

the extraction wells with respect to groundwater flow velocity and direction and yearly energy

demand. The required groundwater volumes and discharges resulting from the energy and

power demand and design concept are shown in table 8.3.

Table 8.3 Required discharge and groundwater volumes for a recirculation system


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An X-number of wells infiltrate a total of about 210.000 m3 groundwater per year, this amount

of groundwater will mainly be infiltrated in the winter period during heating season. Since the

groundwater flow is expected to be around 35 m/year it is required that the thermal radius of

the infiltrated water around each well is also in that order of magnitude otherwise, the

infiltrated thermal energy will reach the extraction wells, sooner or later. The required

situation is schematized in figure 8.5.

Figure 8.5. Desired situation thermal infuence with respect to groundwater flow

For the required thermal radius of 35 m, a total filter length of 50 m is required. In

combination with the conductivity factor of the aquifer of 12 m/d and a generally applied

borehole diameter of 0,6 m, the maximum capacity of a single well can be determined.

Based on the design rules of the Dutch thermal energy branch organization [NVOE, 2006]

the maximum capacity of a single well is 40 m3/hour for 25 m filter and 80 m3/hour for 50 m of

filter (see table 8.4). So, 1 or 2 well pairs are needed to operate a recirculation system. For

both (one and 2 well pairs) situations the total cost has been elaborated. For the operational

cost we included the energy use of the heat pump and the groundwater pump. For the

energy use of the heat pump we assumed an average COP of 3 (because temperature level

from extraction well of recirculation system is not optimal).

Table 8.4 Required discharge and groundwater volumes for a recirculation system

Heating demand Cooling demand

430 kW Power 430 kW

690 MWh Energy 382 MWh

12,00 C T_extraction 12,00 C

7,50 C T_infiltration 16,50 C

4,50 C T_difference 4,50 C

1.605 hours Equivalent hours 888 hours

132.184 m3 volume/y 73.180 m3

82,4 m3/hour discharge 82,4 m3/hour


111

Alternative 2: ATES, ATES with solar heat (a) and ATES with PVT (b)

With a traditional ATES system, heat needed in winter must be stored during summer, since

cooling demand is minimal, the required heating must be obtained from another source. The

facility plans to install PV-solar panel on the roof. A special type of PV-panel can combine

mining of electricity and thermal energy, improving the efficiency of the PV-cells

simultaneously. In 1 hour of sunny weather the PVT panels of Naked Energy can produce

1kW of heat. At the facility location there are approximately 1250 hours per year at which 1

kW can be obtained from the PVT-panels.

The required groundwater volumes and discharges resulting from the energy and power

demand and design concept are shown in table 8.5.

Table 8.5 Required discharge and groundwater volumes for a traditional ATES with solar heat

In combination with the conductivity factor of the aquifer of 12 m/d and a generally applied

borehole diameter of 0,6 m, the maximum capacity of a single well can be determined.

Based on the design rules of the Dutch thermal energy branch organization [NVOE, 2006]

the maximum capacity of a single well is 56 m3/hour for a filter screen length of about 30 m.

So, probably one well pair is needed for this system.

The cost of the PVT panels, including installation is € 800,- /m2.This is € 25,-/m2 more than

normal Thermal solar collectors (http://www.zonnecollectoren-zonnepanelen.nl). Since we

Description Unit Prize Units Cost Units Cost

Exploratory drilling 200,00€ 100 20.000,00€ 100 20.000,00€

Facility area 10.000,00€ 1 10.000,00€ 1 10.000,00€

Horizontal piping 100,00€ 300 30.000,00€ 300 30.000,00€

Drilling 600,00€ 200 120.000,00€ 400 240.000,00€

Pumps, freq. convert., inj. valves 15.000,00€ 1 15.000,00€ 2 30.000,00€

Heat exchanger 10.000,00€ 1 10.000,00€ 1 10.000,00€

Well housing 7.000,00€ 2 14.000,00€ 4 28.000,00€

Engineering and licencing 10% 1 21.900,00€ 1 36.800,00€

Total

Maintenance cost / year 5% 12.045,00€ 20.240,00€

Operational cost / year 0,22€ 257981 56.755,79€ 257981 56.755,79€

Recirculation 1 well pair

240.900,00€

Recirculation 2 well pairs

404.800,00€

Heating demand Cooling demand Solar heat

430 kW Power 430 250 kW

690 MWh Energy 382 308 MWh

16,50 C T_extraction 10,00 10,00 C

7,50 C T_infiltration 16,50 25,00 C

9,00 C T_difference 6,50 15,00 C

1.159 hours Equivalent hours 888 1.232 hours

66.092 m3 volume/y 50.663 17.701 m3

41,2 m3/hour discharge 57,0 14,4 m3/hour


112

need around 375 m2 of surface area of solar panels (both PVT and only solar) the installation

costs can be calculated.

For 3 situations the total costs have been elaborated. For the operational cost we included

the energy use of the heat pump and the groundwater pump. For the energy use of the heat

pump we assumed an annual average COP of 4 for normal ATES and 4,5 for ATES with

P(V)T (because temperature level for ATES is better than recirculation and sharing warm

well with solar panels increases temperature even more, resulting in better COP's).

The PVT-panels produce as much electricity as about 25% of the heat production, the

produced electricity is used for operating the heat pump, reducing the operational costs.

Implementation at facility site

The site roughly has the following dimensions: 800 m x 500 m (phase 1 and 2) or 500 m x

500 m (phase1). From figure 2 and 3 can be seen that the orientation is optimal for the

recirculation system, the infiltration wells should be placed in the most Western of the site.

There is enough space to place infiltration and extraction wells apart from each other.

for the traditional ATES system, implementation at the site is also no problem,

8.3.2 Financial feasibility

The cost of installing both systems is roughly estimated based on drilling costs, additional

materials and equipment (pump, housing etc) and horizontal piping in previous paragraphs.

As can be seen from these tables the 1 well pair recirculation option is the cheapest, but this

alternative comes with the risk that an extra well-pair is needed because of uncertainty in

aquifer performance.

The normal ATES system is only a little bit more expensive and gives already much lower

operational costs. Adding normal solar panels to the system, costs more than twice as much

but only reduces operational costs with 10 %. The PVT panels cost about as much as the

normal solar panels, but cause a significant reduction in operational cost (50%).

Compared to the recirculation 1 well pair option the return on investment and the yearly cost

saving, show that ATES is a very good alternative for the recirculation system, especially

because of the risk for the possible additional well pair. ATES in combination with PVT really

drops the operational cost (70% compared to the recirculation alternative), because of the

required investment its ROI is about 8 years..

Description Unit Prize Units Cost Units Cost Units Cost

Exploratory drilling 200,00€ 100 20.000,00€ 100 20.000,00€ 100 20.000,00€

Facility area 10.000,00€ 1 10.000,00€ 1 10.000,00€ 1 10.000,00€

Horizontal piping 100,00€ 300 30.000,00€ 300 30.000,00€ 300 30.000,00€

Drilling 600,00€ 200 120.000,00€ 200 120.000,00€ 200 120.000,00€

Pumps, freq. convert., inj. valves 15.000,00€ 2 30.000,00€ 2 30.000,00€ 2 30.000,00€

Heat exchanger 10.000,00€ 2 20.000,00€ 2 20.000,00€ 2 20.000,00€

Well housing 7.000,00€ 2 14.000,00€ 2 14.000,00€ 2 14.000,00€

Engineering and licencing 10% 1 24.400,00€ 1 0,10€ 1 0,10€

Cost PT 775,00€ 0 375 290.625,00€ 0 -€

Cost PVT 800,00€ 0 -€ 0 -€ 375 300.000,00€

Total

Maintenance cost / year 5% 13.420,00€ 26.731,26€ 27.200,01€

Operational cost / year 0,22€ 175705 38.655,10€ 157026 34.545,65€ 82271 18.099,61€

comparison to recirculation 1 well pair

ROI 2 13 8

Yearly saving during exploitation 18.100,69€ 22.210,14€ 38.656,18€

ATES

268.400,00€ 534.625,10€ 544.000,10€

ATES PT ATES PVT


113

8.3.3 Legal feasibility

An environmental permit is required, this permit must be requested at the local authority.

Since there are also other ATES systems in the area and the system has no negative

impacts on other interests it is expected that a permit will be issued without problems.

8.4 Conclusion

Both type of systems are possible. In the case of a suitable subsurface the recirculation

system is the most economic option. When it is not possible to install more than 20 m of filter

screen in one well, the PVT & ATES system is better.


114

9 SWATEX GENERAL DESIGN DESCRIPTION (D3-E)

9.1 Introduction

In none of the cases addressed in this research, surface water thermal energy extraction

(swatex) is a possible option. Therefore this concept is briefly addressed in this part of the

report.

9.2 Description of technology

In this paragraph a brief description about different type of surface water systems and typical

application possibilities is given. Figure 9.1 illustrates the various heat fluxes in and out a

stagnant surface water body, obviously in a flowing water body some extra terms are needed

to describe the balance. Solar radiation, evaporation and interaction with atmosphere and

subsurface are the main driving forces.

Figure 9.1 Heat balance surface water [Aparicio, 2008]

9.2.1 Shallow stagnant surface waters

Temperature of shallow stagnant surface waters follow air temperature quite strongly. So

during winter heat can be stored in the surface water and during summer heat can be

extracted from the surface water. With relatively small ponds quite a lot of energy can be

saved. Typical application for this type of surface water is heating purposes. During summer

heat from the pond can be used directly or being stored in an ATES or BTES system.

In the Netherlands there are several residential buildings and blocks with individual houses

which extract thermal energy from shallow surface water (e.g. Den Bosch, Heerhugowaard).

A typical set-up for heat exchange in shallow surface water is illustrated in figure 9.2.


115

Figure 9.2 a typical set-up for a shallow surface water heat exchange [Aparicio, 2008]

9.2.2 Flowing surface water

The temperature of flowing water is less dependent on seasonal climate conditions,

compared to shallow stagnant water. Rivers, streams and tidal areas have fluctuating water

temperatures over the seasons, but less strongly, compared to stagnant waters.

This makes this type of shallow suitable for various applications, dependent on local

conditions. In the Netherlands rivers on have a relatively low temperature, which make them

suitable for cooling purposes. Office buildings can be cooled directly from the surface water.

In some conditions storage of cold water in aquifers during winter is used to facilitate extra

cooling in summer time. For instance in Rotterdam, where several office buildings have an

ATES-system combined with a surface water heat exchange in the river Meuse.

But also heating can be done with flowing water, like some houseboats do in Amsterdam.

A typical set-up for heat exchange in flowing water is illustrated in figure 9.3.

Figure 9.3 Typical set-up for heat exchange in flowing surface water [NVOE, 2011]

9.2.3 Deep surface waters

The top layer of deep surface water follows seasonal air temperature, like shallow waters do.

But the deeper parts have a constant temperature, approximately similar to the surrounding

subsurface temperature, in the Netherlands ~12-15 °C. This makes the water in the deeper

parts of lake or pits a constant source for cooling water. In the Netherlands several lakes are

used to cool buildings with surfaces water from deep lakes (Amsterdam). In the city of

Enschede there is an artificial pit of 10 m deep constructed, with the sole purpose to cool

office buildings.

A typical set-up for heat exchange in deep surface water is illustrated in figure 9.4.


116

Figure 9.4 typical set-up for heat exchange in deep surface water [NVOE, 2011]

9.3 Benefits & Bottlenecks

9.3.1 Compensation for UHI

Any surface water in cities is a cool place and helps to compensate for the urban heat-island

effect (UHI). So applying more water in urban areas and even using the heat capacity of the

water helps to mitigate the effect of UHI. Surface waters can be placed at strategic places, so

called UHI hot spots.

9.3.2 Adaptation for Climate change

Changing climate triggered the transition to sustainable energy systems. Using surface water

for heating and cooling purposes is a sustainable fulfillment of space heating and cooling.

Since climate will keep on changing, it is important to be able to meet energy demand with

robust/resilient systems. For that it is needed to combine different sources of sustainable

energy. A surface water system will fit perfectly in a climate system with other sustainable

systems like ATES, heat pump, solar collectors etc.

9.3.3 Legislation Water temperature / quality (WFD)

Changing waters temperature affects water quality, since many chemical equilibriums are

temperature dependent. So exchanging thermal energy can only be done when regulations

are met accordingly to European and local laws.

Extracting heat is generally not a problem, since cooling of water is considered to improve

water quality. When raising surface water temperature, it is best to get informed about the

regulations applying on the water body under consideration.

9.3.4 Clogging and bio fouling

A lot of suspended and dissolved particles can be found in surface water. Next to that,

surface water contains a lot of biological and bacterial matter. This may cause clogging of the

heat exchanger or intake point or damage to pumps. Typical problems are mechanical

clogging by suspended particles and bio fouling, also causing clogging and loss of heat-

exchange efficiency.

Both processes must be managed to sustain the surface water heat-exchange system. When

the surface water contains a lot of suspended particles a seeve or similar device can do the

trick. When there is a lot of biological or bacterial activity, chemical additions or a strict

cleaning schedule will prevent clogging and loss of efficiency.


117

9.4 Literature

Slingerland, Mitigation of the Urban Heat Island effect by using water and vegetation,

2012

Aparicio, Urban Surface Water as Energy Source & Collector, 2008

NVOE, ENERGIE UIT OPPERVLAKTEWATER, 2011


118

10 BUSINESS DEVELOPMENT (D4)

10.1 Introduction

In order to assess the economic performance of ATES systems a number of ATES systems

is evaluated on their technical and economic performance. To this end a number of

operational data are collected, both from literature as from case studies that contributed to

this project.

10.2 Typical technical design for ATES systems

A typical ATES system consists of one or several pairs of hot and cold wells. During the

cooling cycle water from the cold well is used to cool the building by taking up the heat

through a heat exchanger. The transfer of heat can be enhanced by a heat-pump. The

heated water is then stored in the hot well for use during heating operation. During the

heating cycle warm water is pumped from the hot well and used to (pre)heat air and/or

radiators used for heating the inside of buildings, often in combination with a heat-pump. The

use of a heat pump affects the overall efficiency (Seasonal Performance Factor or SPF) of

the ATES system.

10.3 Literature review

From the reviewed literature different data was collected. Literature reviewed described

ATES systems in Sweden (Andersson, Bjelm), Belgium (Vanhoudt, Hoes), Turkey (Paksoy)

and Germany (Sanner, Schmidt).From the literature it was concluded that not all systems

have the same performance, and final profitability depends for an important part on the

equilibrium between demand for cooling and heating, the Seasonal Performance Factor

(SPF) and avoided investments and used energy efficiency of the ‘traditional’ system. Typical

performance indicators for the ATES are listed in Table 10.1. Some indicators are the result

of operational measurements from the ATES systems, other are design estimates.

Table 10.1 Typical performance indicators for ATES systems

Performance indicator

Min Max Suggested “average”

COP Cool (ATES) 5.0

SPF Cool (ATES) 16 58 26

COP Heat (ATES) 4.1 5.6

SPF Heat (ATES) 5.5 7.1 5.9

10.4 Business case ATES system

The business case for the ATES system based on literature review is based on the case

from Vanhoudt (2011) and describes an ATES system for a hospital in Belgium. The

business case is based on the system description from the publication in which cost for

operation and maintenance are added based on cost estimated for O&M contracts from a

service provider amounting to roughly 3,5 % of investment costs per year.

The characteristics of the ATES system are listed in Table 10.2.


119

Table 10.2 Characteristics of the ATES system as described in Vanhoudt (2011)

Parameter Value

Maximum flow per well 100 m3/h

Maximum cooling power 1.2 MW

Diameter drilling 0.8 m

Depth wells 65 m

Length filters 36 – 40 m

Thickness aquifer 30 – 40 m

Number of cold wells 1

Number of warm wells 1

Distance between cold and warm well 100 m

Undisturbed groundwater temperature 11.7° C

Injection temperature warm well 18° C

Injection temperature cold well 8° C

SPF cooling ATES 26

SPF heating ATES 5.9

Over on a three year period data was collected for design, construction and operation as

presented in Table 10.3. Operational data is averaged over the monitoring period of three

years. For comparison the reference situation, consisting of gas-fired boilers for heating and

cooling machines are included in the table.

Table 10.3 Business Case ATES system as described in Vanhoudt (2011)

Description ATES

(‘000 €)

Reference situation (‘000 €)

Investment Costs Underground installation (k€) Overground installation (k€) Total Installation costs (k€) Extra study and engineering ATES (k€) Total Subsidies Total, incl. subsidies

299 266 565 130

695 244 451

241 241

241

241

Operational data and cost

21

Cooling supply (MWh) Elec. Consumption cooling (MWh) Total cooling costs (k€) Heating supply (MWh) Gas consumption for heating (MWh) Gas cost for heating (k€) Elec. Consumption for heating (MWh) Electricity costs (k€) Total heating costs (k€) O&M costs (k€) Total operational costs (k€)

872 33 3.7

1335 - -

227 25

28.7 24 53

872 249 27.4

1335 1571

55 - -

55 6

88

Simple payback time Subsidies included (years) Subsidies excluded (years)

5.9 12.8

IRR22

Subsidies included Subsidies excluded

14 % 4 %

21

Based on an elec. price 110 k€/MWh and gas 35 k€/MWh 22

Based on 30 years lifespan of the ATES system with a reinvestment of 300 k€ in year 15


120

Another business case was made for the case study of an apartment complex in Modena,

Italy. For this case the investment capacity was calculated based on the potential savings

that can be obtained when an ATES system is used instead of a traditional city heating

system with individual cooling for each apartment. Based on the specific characteristics of

the individual apartments and design criteria as specified in Table 10.4, a business case was

made in order to determine investment capacity for the ATES system. Based on the business

case in Table 10.5 a total of 1.8 M€ can be invested in the ATES system, and an eventual

PVT system to compensate an eventual imbalance between heating and cooling demand, in

order to arrive at a payback period of 10 years.

Table 10.4 Characteristics of the ATES system for apartment complex in Modena, Italy

Heating demand 45 KWh/m2

Cooling demand 50 KWh/m2

Hot water demand 2,5 MWh/apartment

No. apartments 600 apartments

Surface apartment 80 m2 /app

COP cooling (ATES) 30,0 COP heating (ATES) 5,0 COP trad cooling 3,6

Eff. gas heating 85%

Electricity (private) 229 €/MWh

Electricity (corporate) 169 €/MWh

Gas 42 €/MWh

Air conditioner 600 €/# excl. Installation

Table 10.5 Business Case ATES system for apartment complex in Modena, Italy

Reference: 90c centralised boiler and indv. aircon

ATES system

(€) (€)

Investment Costs 360.000 1.800.000

Maintenance Costs 7.200 63.000

Energy Costs Heating 180.847 122.976

Energy Costs Cooling 152.667 13.440

Total Yearly Cost 340.714 199.416

Yearly savings

141.298

Payback period

10

10.5 Economic stimuli

ATES is already quite attractive as source of sustainable energy, which is shown by the fast

growth in number of installations in the Netherlands. Considering the results of the inventory


121

performed in this project, there is no reason that this would be different for the other regions

in Europe with suitable aquifers. Therefore the subject of possible incentives is only touched

briefly, here.

Economic stimuli are already inherently present when ATES is especially necessary for

cooling, because of its (cost-) efficiency in relation to conventional air-conditioning. When

both cold and heat are needed, the payback period is also quite acceptable. Only when

considerably more heat than cold is required, fossil energy is still more attractive financially,

although the innovative combinations studied in this project, make ATES also for those

situations gradually more economically viable. To support this development in ATES

efficiency in the years to come, authorities could use financial instruments like subsidies and

tax deductions temporarily. ATES installations should be considered as green investments.

The necessary funds can be created by increasing taxes on fossil energy source

Governments could also help by bridging the gap between the site or building owner, who

has to do the investments, and the site user or tenant, who usually profits from lower energy

bills. With tax deductions on the investments, paid for again by increases on fossil energy

taxes, installation of ATES becomes evidently attractive for both parties. Such a tax

arrangement would definitely stimulate the construction of more systems. But it is not

necessarily the government that has to take action; also market parties could encourage

business with soil energy. For instance, banks can create comparable incentives by initiating

agreements that are profitable for all parties.

10.6 Conclusion

The described business cases illustrate the economic feasibility of ATES systems, providing

there is equilibrium in demand for heating and cooling. The calculated payback period,

between 5 and 10 years, is promising, considering the relative inexperience with the

technique. Energy savings are especially high for cooling demand which is delivered much

more efficient by an ATES system than a traditional system, with COP of 3.5 for traditional

systems and around 25 for ATES systems. ATES systems can be supported by photovoltaic

or solar thermal systems, especially when heating demand is larger than cooling demand.

An added advantage of ATES systems can be the lowering of peak demands for cooling,

which in turn will lower peak demands for electricity, which could lead to lower electricity bills

(in case peak tariffs are in place) and possibly lead to life extension of electricity grids, due to

lower peak demands.

Furthermore, ATES systems have significant savings in greenhouse gas emissions, which in

turn can support sustainability and climate change goals. These last two reasons could open

discussions on subsidies or combined financing of ATES systems as an activity in support of

policy goals on reduction of climate change or savings for the operator of the electricity grid.

Financing arrangements between different stakeholders should be investigated to make the

implementation of ATES systems easier for individual home owners and owners of office

buildings.


122

10.7 Literature

Andersson, O., Ekkestubbe J. and Ekdahl, A., UTES (Underground Thermal Energy

Storage)—Applications and Market Development in Sweden, 2013

Bjelm, L., Alm P., and Andersson, O., Country Update for Sweden, 2010

Hoes, H., Robeyn, N., Eindrapport KWO bij KLINA te Brasschaat. ANRE

Demonstratieprojecten, VITO report (2005) (report in Dutch).

Paksoy, H.O., et. al., Heating and cooling of a hospital using solar energy coupled

with seasonal thermal energy storage in an aquifer, Renewable Energy 19 (2000)

117-122

Sanner, B., et. al., Underground Thermal Energy Storage for the German Parliament

in Berlin, System Concept and Operational Experiences, Proceedings World

Geothermal Congress 2005

Schmidt, T., Müller-Steinhagen, H., The central heating plant with Aquifer Thermal

Energy Storage in Rostock – Results after four years of operation, 2004

Vanhoudt, D. et. al., An aquifer thermal storage system in a Belgium hospital: Long-

term experimental evaluation of energy and cost savings, 2011, Energy and Buildings

43 p 3657-3665


123

11 PUBLICATIONS & MEETINGS (D5)

Project partners kept in touch frequently by mail and telephone. Also telephone and video

conferences were organized. Local consortium partners had meetings regularly. Several

partners from different countries met physically in Utrecht, Antwerp and Bologna.

Activities related to soil energy aimed at parties outside the project are listed in tables 11.1

and 11.2.

Table 11.1 Publicity through meetings, workshops and conferences

Type of meeting Occasion Date Objective

Workshop Climate KIC E-

use (aq) Modena

consortium

Workshop site Modena,

Bologna.

Participation Climate KIC

E-use (aq) Modena

consortium (Deltares,

Aster, HERA, UNIBO,

Wageningen UR, Arcadis)

May 21-22, 2014 Define feasibility of aquifer thermal energy

storage (ATES) on the redevelopment site ex-

Mercato Bestiame in Modena (Italy) and

definition of (future) process steps for

application

Workshop Climate KIC E-

use (aq) Nike Belgium

Workshop site Nike

Belgium

Participation Climate KIC

E-use (aq) Nike

consortium (Deltares,

Nike, Wageningen UR,

Arcadis)

February 20th,

2014

Brainstorm on the possibilities for ATES at the

NIKE site, what combination of Photovoltaic

cells, well lay out and subsurface concept is

suitable for the new development of an

energy neutral office and warehouse

Workshop, for Dutch public

authorities

Workshop Utrecht, The

Netherlands

Participation of

approximately 40 different

municipalities, provinces,

and semi-governmental

organisations

March 11th, 2014 How to handle groundwater plumes in

aquifers. When are remedial interventions

necessary, to what extent and discussion

about the differences in interpretation and

implementation of the Dutch Soil Protection

Law. Part of the workshop was to outline the

possibilities of ATES as an instrument to

contain plumes and to give an impulse to

biological degradation of contaminants

Assembly of Acknowledge

Soil Professionals Belgium

Presentation during the

Annual Members Meeting

in Leuven

March 18th , 2014 Upon developments in groundwater

management in the Netherlands,

Groundwater use and groundwater quality.

Barriers and possibilities

Presentation Climate KIC RIC partner

meetings

December 2013

and March 2014

During the Climate KIC RIC Partners meeting

in December 2013 and March 2014, the

EUSE project was presented to the regional

C-KIC partners

Tutor groundwater

management

Module soil and

groundwater, University of

Agriculture

(HAS Den Bosch)

Participation of


(mainly) governmental

organisations

May 15th, 2014 Part 1: ATES and remediation

Part 2: Advantages of arrangement of

activities in the subsurface, and available

methods


124

R2B Research to Business International exhibition on

industrial research and

innovation in Bolgona Italy

June 4-5, 2014 On the occasion of a workshop within the

ninth edition of the international exhibition on

industrial research and innovation, the

Climate-KIC was presented by ASTER.

Amongst the Innovation Pillar activities, the E-

Use project was illustrated. With 5.700 visitors

from the research, policy and business

sectors, the exhibition is the reference event

in Emilia-Romagna for innovation.

Workshop Workshop Regione

Emilia-Romagna “LA

GEOTERMIA A BASSA

ENTALPIA: SITUAZIONE

ATTUALE E

PROSPETTIVE”

June 10th, 2014 ASTER participated to the workshop

organized by the Emilia-Romagna Regional

Energy Service in the framework of the EU

project LEGEND as networking activity to

disseminate the results of the E-USE project.

(http://energia.regione.emilia-

romagna.it/documenti/documenti-

2014/Programma_def.pdf)

Infosheet An infosheet about E-USE

has been issued to the

survey of the RES-HC

Project (http://www.res-hc-

spread.eu/)

2014 Best practice example for RES-HC Project,

surveying best practices in the field of thermal

energy. The IEE-project RES H/C intends to

develop renewable heating and cooling plans

for six European Pilot Regions (in Spain, Italy,

Austria, Latvia, Greece and Bulgaria).

Conference In Situ Remediation

Conference 2014, London

September 2nd

-4th,

2014

Presentation about sustainable use of the

subsurface in The Netherlands, and the

surplus value of ATES for sustainable energy

and the potential of improvement of water

quality in contaminated aquifers

Conference Sustainable Remediation

2014, Ferrara Italy

September 17-18-

19 2014

Case study presentation about subsurface

use and groundwater quality for an

international audience, and workshop

discussions on sustainability appraisals for

the subsurface

International exhibition REMTECH, Remediation

Technologies, Ferrara

Italy

20th September

2014

Participation to the international exhibition on

remediation technologies

Workshop, for industrial

companies in the

Netherlands

Workshop Lelystad, The

Netherlands

Participation of


industrial companies, both

Dutch as international

conglomerates

September 18th,

2014

How to handle groundwater plumes in

aquifers. Triggers for remedial activities out of

public and private perspective. Part of the

workshop was to outline the possibilities of

ATES as an instrument to contain plumes and

to give an impulse to biological degradation of

contaminants

Network of Industrially

contaminated land In

Europe

Presentation at workshop

meeting in Namur,

Belgium

November 15th ,

2013

Liability issues, subsurface use (ATES) and

groundwater quality. How can groundwater

management remove barriers for groundwater

use and effective quality management

Conference Oral presentation at the

workshop “Low enthalpy

geothermal energy:

drivers for the market

uptake and an effective

supply chain”, Bologna

Italy

14th November

2014

Workshop with 50 professionals about

strategies to promote low enthalpy

geothermal energy in Emilia-Romagna. The

presentation included a presentation on E-

USE and on the concept of ATES in general.

http://www.ervet.it/ervet/wp-

content/uploads/2014/10/Legend_flyer_v2.pdf

Traineeship Internship Deltares 2014 Internship Clothilde Pineaud, Hydrological

efficiency of HT-ATES combined with

geothermal plant

Conference Preserving the flow of life

conference in Lyon

October 2014 Project presentation on water & energy

conference

http://energia.regione.emilia-romagna.it/documenti/documenti-2014/Programma_def.pdf



http://www.res-hc-spread.eu/

http://www.res-hc-spread.eu/

http://www.ervet.it/ervet/wp-content/uploads/2014/10/Legend_flyer_v2.pdf

http://www.ervet.it/ervet/wp-content/uploads/2014/10/Legend_flyer_v2.pdf


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Table 11.2 Publicity through articles and other publishing

Type of publication Medium Publication date Principal theme

Publication International Waterworld

“Groundwater Energy and

Remediation: Realising the

Synergy in The Netherlands”

www.waterworld.com

May 2013 Role of ATES in sustainable groundwater

management, and an illustration of the surplus

value by several cases

Paper Technology Innovation News

Survey

“Combining shallow geothermal

energy and groundwater

remediation”

www.clu-in.org

March 2014 Scientific reflexion on combination of ATES and

remediation, primarily based on results of Dutch

research programme “Meer Met Bodemenergie”,

which aims on increase potential of ATES

systems

Popular press article Magazine Bodem, volume April April 2014 Tomassetta C., Griffioen J., van Ree, D.,

Toepassing van Life Cycle Analysis op WKO

Web publication Website AIDICO

July 2014 AIDICO has published on their website the E-

USE Project: http://www.aidico.es/aidico-

participar-en-el-impulso-de-empleo-de-la-

energia--sostenible-de-los-acuiferos-a-escala-

europea--a-traves-del-proyecto-euse-aq-com-

74-50-95-1656/

Flyer Flyer E-use (aq) European-

wide-use of Sustainable Energy

from aquifers

Distribution from AIDICO office,

et cetera

Juny 2014

Chapter in book (to

be published)

Remediation techs and apps

“Managing contaminated

groundwater: Novel strategies

and solutions in the

Netherlands”

n/a An overview of the policy shift during the last

decades regarding groundwater contamination,

and the possibilities that this shift created for

sustainable use of the subsurface. Both ATES

and area wide groundwater management are

instruments that can contribute to an

improvement of groundwater quality

Thesis MSc Thesis October 2014 MSc Thesis UU, Roy Veugen, Environmental

Impacts of subsurface buildings

Thesis MSc Thesis, Utrecht University October 2014 Moulopoulos, A., Life Cycle Assessment of an

Aquifer Thermal Energy Storage system,

Exploring the environmental performance of

shallow subsurface space development

Publication Journal of Contaminant

Hydrology 162, p 208-218

2014 Ni, Z et al. (2014) Effectiveness of Stimulating

PCE Reductive Dechlorination: A Step-wise

Approach

Popular press article Cobouw (Dutch) 2014 Popular Press Article in Cobouw over het

gehonoreerde project in TKI-EnergGO:

Glasvezel meet gedrag van WKO

Popular press article Delta Life 1 2014, Deltares

(bi-lingual English and Dutch)

2014 W. Sommer, Maximising the returns from ATES

systems (Maximaal rendement uit WKO

systeem)

Journal paper Applied Energy 137, p 322-337 2015 Sommer, W. et al. (2015) Optimization and

spatial pattern of large-scale aquifer thermal

energy storage

http://dx.doi.org/10.1016/j.apenergy.2014.10.019

http://www.waterworld.com/

http://www.clu-in.org/

http://www.aidico.es/aidico-participar-en-el-impulso-de-empleo-de-la-energia--sostenible-de-los-acuiferos-a-escala-europea--a-traves-del-proyecto-euse-aq-com-74-50-95-1656/





http://dx.doi.org/10.1016/j.apenergy.2014.10.019


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Book chapter Engineering Geology for

Society and Territory - Volume

5, DOI:

http://dx.doi.org/10.1007/978-3-

319-09048-1_232

© Springer International

Publishing Switzerland 2015

2014 C Tomasetta, CCD.F. Van Ree, and J. Griffioen,

Life Cycle Analysis of Underground Thermal

Energy Storage, in G. Lollino et al. (eds.)

Chapter in Book

“Soil remediation –

Applications and

new technologies,

CRC press, editor:

prof. T. Albergaria

We have written a chapter on

“Novel strategies in

groundwater management”

To be edited and

published

A lengthy chapter on new groundwater use and

management, interaction of ATES with other

soil functions

Thesis Thesis MSc Mark Bruggeling,

conducted at Wageningen UR

and Arcadis

“Effect of additional remediation

on Volatile Organochlorine

Solvents (VCH) contaminated

sites in combination with Aquifer

Thermal Energy Storage

systems”

March 2015 Potential of combining additional remediation

techniques with an ATES system at a

contaminated site in the Netherlands. As

research method a RT3D-groundwater model is

used

Article Newspaper / magazine

Germany

n/a To be realized within Innovation project

Article Newspaper / magazine Italy n/a To be realized within Innovation project

Article Newspaper / magazine Spain n/a To be realized within Innovation project

Article Newspaper / magazine Belgium n/a To be realized within Innovation project

Article Newspaper / magazine UK n/a To be realized within Innovation project

Article Internet publication in English n/a To be realized within Innovation project

http://dx.doi.org/10.1007/978-3-319-09048-1_232

http://dx.doi.org/10.1007/978-3-319-09048-1_232


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12 OVERALL CONCLUSIONS

Main lessons learnt from the project

Socio-economic, legislative and some technological barriers prevent widespread application

of soil energy in Europe so far. But these can be overcome. Prove of attractiveness of ATES

applications, because of its cost-effectiveness and its huge potential impact on reduction of

fossil fuel consumption and greenhouse gas production, will promote the use of this type of

renewable energy. Therefore, we advise to run pilots of innovative ATES-solutions in several

European countries, showing how to overcome barriers. This will enable large-scale

deployments of ATES in Europe.

State-of-the-art in Europe

Currently, for the Netherlands it is estimated that approximately 2500 open ATES systems have been installed at a pace of about 450 systems per year with an average thermal output of 130 kW per system. In the rest of Europe, open ATES system can hardly be found, due to the barriers which are mentioned above and elaborated upon below.

Barriers addressed and removed

For all countries:

1. disappointing quality levels and hampering robustness of the installations;

2. knowledge and skills divided between consulting and contracting companies and

maintenance staff;

3. unpredictability’s because of unfamiliarity with the underground and its

characteristics.

For countries with an immature market:

4. lack of knowledge and experience;

5. lack of adequate regulations;

6. presumed relatively large initial investments with unclear savings during operation.

For countries with a more mature and grown market:

7. interference between ATES systems;

8. interference with polluted groundwater;

9. shifting opinions considering presumed negative impact on groundwater quality.

Proposed follow-up

With demonstration projects, it can be illustrated how these barriers can be removed. The

efforts of the Pathfinder resulted in pinpointing the following example sites and pilots:

• Netherlands (example sites): Performance of sophisticated monitoring in Delft,

Eindhoven and Utrecht. Existing innovative ATES system in combination with

enhancing natural degradation of contaminants. Creation of innovative Bio

Washing Machine already in progress aided by numerous state-of-the-art ATES,

which are operative for several years, some even for tens of years (barriers 1, 3,

7, 8 and 9). Lessons learned from these sites will immediately be used for the

pilots, but also made available for commercial ATES projects in the involved

regions that start before the end of the Innovation project.


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• Italy (pilot 1): Modena urban area (ex-Mercato Bestiame) under redevelopment

with groundwater contamination from nitrates (tackling barriers 2, 3, 4, 5, 6 and 8);

design and realization of ATES with water denitrification process plant and

innovative ATES integration within a new cogeneration power plant.

• Spain (pilot 2): Public swimming pool and sport centre; innovative solution for

circumventing opposing regulations regarding re-infiltration of groundwater use

(barriers 4 and 5) and at the same time dealing with local water scarcity. The

water is kept underground and used for simultaneous delivery of both heat and

cold.

• Belgium (pilot 3): Nike distribution centre in Ham; smart design and increased

economic feasibility through innovative combination of solar heat and ATES

(barrier 3 and 6). Performance of both solar as well as soil energy will be

increased by using PVT-cells (combination of photovoltaic and thermal energy)

and storage of solar heat in the aquifer.

• Germany (pilot 4): Frankfurt shopping centre, hotel and office building (barriers 3,

4, 5 and 7); innovative design, based on groundwater model to be validated, with

restricted groundwater flow. German mining law legislation is seen as major

obstacle because a thorough groundwater plan, proving “no influence” outside the

premises, is required to install an ATES system. Also, existing licensed “claims”

might require bilateral negotiations with license holder. Including PVT technology.

• Additional pilot(s) in Sweden, France and / or Eastern Europe. If possible with

surface water thermal energy extraction (SWATEX). Yet to be found.

Involvement of business partners

The following project and business partners are involved in sites and pilots mentioned above:

Example sites Netherlands - Deltares, Arcadis, TU-Delft, Wageningen University

Pilot 1 - ASTER, Wageningen University, Arcadis, HERA and University of Bologna

Pilot 2 - Aidico, TU-Delft, Itecon, Council of Almazora

Pilot 3 - Arcadis, TU-Delft, Naked Energy, Nike

Pilot 4 - TU-Darmstadt, Wageningen University & Naked Energy

Additional pilot(s) - Possibly with SWATEX, developed by TU-Delft. First contact with

EDF.

Main competitors in Europe

Because of the barriers listed above, competition is hardly present in Europe, at the moment.

However, present project partners would even welcome more parties using the technology,

since it will generate much more business when they can also contribute to parallel projects

with their expertise.

Market segments

Potential end-users are parties like property developers, owners of building complexes and

housing corporations. Possible business partners are consultants, contracting and

construction companies and investors.

Business model

ATES is especially attractive when necessary for cooling, because of its (cost-) efficiency in

relation to conventional air-conditioning. When both cold and heat are needed, the payback


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period is also quite acceptable. Only when considerably more heat than cold is required,

fossil energy is still more attractive financially, although the innovative combinations studied

in this project, make ATES also for those situations gradually more economically viable.

Operational value chain with business partners

Because of the inherent economic attractiveness of ATES it is specifically important to

demonstrate the applicability of the technology for potential end-users and possible business

partners in their own region. There-after it is expected that he technology will sell itself.

However, for the first demonstrations, innovative adapted designs, meeting local conditions,

are needed, as well as elaborate monitoring, in order to prove the effectiveness of the

technology and the possibilities to overcome barriers, and extensive publicity. Customers are

not willing to pay for those costs connected to first regional applications. For this reason an

Innovation project, that will launch the technology in different parts of Europe, thus creating

regional flywheels, is very important.

Potential for scalability and replicability

As a result of successful pilots, showing compatibility with local conditions, more ATES

installations will be started in the regarding regions. Initiating these, is the ultimate goal of the

E-USE(aq) Innovation project. It is likely that already after the pilots start showing their

promising results, local partners are able to identify new opportunities.The flywheel effect to

be initiated locally and regionally, will lead to national adoption in several countries and

subsequently to Europe-wide use of the technology.

e-use(aq) pathfinder project...whilst ates could offer an opportunity for the effective use and...

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