case studies for chp 370

7/27/2019 Case studies for CHP 370

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GOOD PRACTICE CASE STUDY 370

The use of combined heat and powerin community heating schemes

Four ca se s tud ies

s Econo mic b enefitsfor local authoritiesand tenants

s Combined hea t a ndpower units installedwi th ca p ita l cos t srecouped in three tofive years

s Improved co mfortlevels for tenants

s Signif icantreduct ions in carbondioxide emissions


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INTRODUCTION

COMBINED HEAT AND POWER IN COMM UNITY HEATING SCHEMES

Modern community heating systems are a reliable,easy to maintain and efficient way of heatingblocks of flats, social housing and groups of buildings. The advantages (when compared tousing individual boilers) are that communityheating:s provides low-cost heating and hot water for

tenantss uses fuel more efficientlys reduces carbon dioxide (CO 2) emissions.

Community heating systems are highly efficient inthe use of fuel. By using combined heat and power(CHP) in a community heating system itsefficiency can be increased still further, with thefollowing benefits:s cheap electricitys income for landlords from the sale of

electricitys even lower CO 2 emissions.

Community heating supplied by a CHP system istherefore an excellent way to:s control and reduce costss improve standards of comfort for tenantss reduce environmental impact and energy use.

This document is intended for local authorityhousing and housing association managers whoare considering installing, refurbishing orincreasing the efficiency of a community heatingsystem. It describes the advantages of using CHP toprovide community heating and discusses how itcan be installed and financed. The case studiesprofile four local authorities use of communityheating with CHP to provide heat and power in avariety of circumstances.

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WHAT IS COMMUNITY HEATING?

COMBINED HEAT AND POWER IN COM MUNITY HEATING SCHEMES

A community heating system uses a central boiler toheat a number of buildings or dwellings. It canserve both domestic and business sectors. Schemescan range in size from those serving a single blockof flats to those serving whole neighbourhoods.

The boiler plant generates hot water and is usuallyfuelled by gas, but it can also use oil, coal, waste,or a combination of these. The hot water iscirculated through pipes to buildings on thescheme. In some systems the hot water then passesthrough the radiators in the dwelling, in othersheat exchangers take heat from the mains for usein each dwelling. Apart from the absence of aboiler, there is no difference for the occupantsbetween a building using community heating andone with conventional central heating.

Community heating is one of the most cost-effective and environmentally friendly ways of providing heat. Its greater fuel efficiency meansthat emissions of CO 2 can be vastly reduced, thushelping local authorities meet their commitmentsunder Local Agenda 21 (LA21) and the Home

Energy Conservation Act (HECA). Fuel costs can beup to 40% lower than for other heating systems.There are two reasons for this: the boiler can workat optimum efficiency for more of the time; and,because the boiler has a large load, fuel can bepurchased more competitively.

Cheaper fuel means that tenants can afford to keeptheir dwellings warm and, because buildings areheated properly, the risk of damage fromcondensation and mould is reduced. Tenants aregenerally very satisfied, thereby reducingcomplaints, voids and management costs.

Maintenance costs are also lower than forconventional heating schemes because there is

only one boiler to maintain, rather than a largenumber of boilers situated in many properties.

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BENEFITS OF COMMUNITY HEATING

For landlords:s lower maintenance costss lower fuel costss lower CO 2 emissionss happier tenantss fewer voidss competitive fuel purchasings the opportunity to use CHP.

For tenants:s cheaper heat and hot waters reduced condensation and moulds improved levels of comfort.

For the environment:s reductions in CO 2 emissionss reduced usage of fossil fuels.

At Giles Close, Birmingham, average internaltemperatures increased by 5C, improvingoccupant comfort. Annual fuel savings were134 for each dwelling, and CO 2 emissionswere cut by the equivalent of over 27 tonnesof carbon each year (see page 9).


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WHAT IS COMBINED HEAT AND POWER?


CHP systems produce both heat and electricity froma single plant. This makes them far more efficientthan most power stations, which are not designedto make use of the surplus heat they produce whengenerating electricity. Instead, this heat is exhaustedinto the environment. CHP systems use the wasteheat they produce to provide hot water for centralheating systems and other purposes, as well asproducing electricity for local use. Power stations aregenerally about 35% efficient, while a CHP systemis, on average, 85% efficient.

The high efficiency of CHP systems also results inmajor environmental benefits, including significantreductions in the use of fossil fuels, thereby helpingto conserve the worlds finite energy resources.There are also reductions in CO 2 emissions, acontribution to climate change, factors of whichare the greenhouse effect and global warming.

In addition to the environmental benefits of CHP,local authorities also benefit from the opportunityto obtain cheaper electricity, which can be sold totenants, used to service the common parts of buildings, or exported through the grid, thusproducing income for the local authority. There isincreased security of power supply as the CHP cansupply power should the grid fail (and vice versa).

CHP can be installed with no capital costs to thelocal authority, through third-party energy supplyagreements.

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Leicester City Council has saved 48 000annually following the installation of CHP atSt Andrews. At the same time, CO 2 emissionshave been cut by the equivalent of over55 tonnes of carbon each year (see page 8).

BENEFITS OF COMBINED HEAT AND POWERFor landlords:s lower fuel usages it can be installed without capital costs electricity to use or sells a secure power supply.

For tenants:s cheap heat, hot water and power.

For the environment:s reductions in CO 2 emissionss even greater reductions in the use of fossil

fuels than with community heating alone.


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WHEN TO USE COMBINED HEAT AND POWER FOR COMMUNITY HEATING


CHP should always be considered when:s a community heating scheme is planneds refurbishment of existing community heating

is undertakens installing new boiler plants replacing or refurbishing existing plants reviewing electricity supply or standby

electrical generation capacity or plants considering energy efficiency strategy in

general.

Community heating should be considered whenrefurbishing heating systems in blocks of flats orsheltered housing. The refurbishment of old-fashionedcommunity heating schemes can often be more cost-effective than replacing them with individual systems.

When considering CHP the key criteria are thedemands for heat and power. To be economicallyviable the CHP system normally needs to run for atleast 4000 hours per year. Points to consider are:s the base loads for the system, such as heating,

domestic hot water (DHW) and power forcommon areas, lifts and heating pumps

s whether there are other local heat or powerloads that could be connected to thecommunity heating scheme to use the outputduring the day when the demand fromhousing is low.

Funds for community heating and CHP can comefrom three sources.s The local authoritys own funds.s Equipment supplier finance (ESF) most

equipment suppliers will provide finance forthe purchase of CHP, allowing the payments tobe phased over several years, and so financedfrom the savings.

s Discounted energy purchase the CHPsupplier installs and operates the plant andsells the heat and power produced to theauthority at an agreed price per unit. With thispurchase method there are no capital costs.This is the scheme used by Birmingham CityCouncil at Giles Close Flats.

Grant scheme initiatives may be availablefor suitable projects. Current information ongrants may be obtained from the CombinedHeat and Power Association (CHPA) (see FurtherInformation on page 10).

PRIVATE FINANCE INITIATIVE

CHP schemes can be financed under the Private

Finance Initiative (PFI). Assistance, support andadvice on setting up a PFI scheme can be obtainedfrom The Public/Private Partnerships Programme,35 Great Smith Street, Westminster, London SW1P3BJ. Tel 0171 664 3145. Fax 0171 664 3030.

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When the London Borough of Newhamrefurbished College Point it considereddecentralisation, but the feasibility studyshowed that community heating with CHPwas more cost-effective (see page 6).

One reason the scheme at Cruddas Park is sosuccessful is because the high daytime loadof the shopping centre complements thehousing demand in the early mornings andevenings (see page 7).


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CASE STUDY 1 COLLEGE POINT, LONDON BOROUGH OF NEWHAM


BACKGROUND

College Point is a 1960s high-rise buildingcontaining 123 flats. In the early 1990s, it was duefor major refurbishment and the heating systemwas a priority area. The flats were heated by theoriginal community heating system andmaintenance was expensive, the boiler was oil-firedand situated on the roof, and the heating providedto tenants was partial and switched on seasonally.

The London Borough of Newham was attracted bythe financial and environmental benefits of CHPused with community heating, but it alsoconsidered installing individual gas-fired centralheating in each flat. Before making a decision, itcommissioned a feasibility study on using CHP forCollege Point. The feasibility study showed thatusing community heating with a CHP plant was the

best option; that the plant would have financial andenvironmental benefits; and that it would have apredicted payback period under five years.

IMPLEMENTATION

The scheme was funded jointly by the Council andthe Governments Green House Programme (nolonger running). The CHP plant was installedtogether with two new boilers in a purpose-builtboiler house situated close to College Point. It isused to preheat water before it passes back to themain boiler plant. The CHP plant provides heatingvia radiators and serves DHW cylinders in each flat.

The CHP plant provides the landlord withelectricity for lighting in communal areas, for liftsand for the boiler house. Surplus electricity is soldto the regional electricity company (REC),London Electricity.

RESULTS

The scheme has been very successful.s Tenants have full central heating and hot

water available whenever they require it.

s The CHP plant provides power for the landlordto use and sell.

s Income is generated from selling surpluselectricity to the REC.

s Energy savings of 3.2 GJ and reductions in CO 2emissions equivalent to 90 tonnes of carbonper year have been achieved.

s The payback period will be less than five years.

Capital cost 50 160Annual maintenance costs 2364Annual fuel saving 5808Annual electricity sales 7200Net annual savings 10 644Payback 4.7 yearsCarbon saving per year 90 tonnes

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DATA TABLE


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CASE STUDY 2 CRUDDAS PARK, NEWCASTLE UPON TYNE


BACKGROUND

The Cruddas Park complex comprises a 196720-storey high-rise block with 159 flats, a shoppingmall with an underground car park, a socialservices care home and a housing departmentoffice. The original heating system was inefficientand the boilers were oversized.

In 1993, the block of flats was due for majorrefurbishment. Newcastle City Council was interestedin incorporating a CHP plant into the central boilerfacility during this refurbishment because it believedthe financial benefits could be passed on to thetenants as affordable warmth. A feasibility studyindicated that it would be of greater benefit toprovide heat and electricity to other buildings in thecomplex, as this would enable the CHP system to runat full potential for longer periods.

IMPLEMENTATION

The scheme was financed under the GovernmentsGreen House Programme (no longer running).

The CHP plant was installed in series with the

three existing boilers. These were fired by refuse-derived fuel (RDF), coal and oil respectively,although normally only the RDF boiler operates.

The CHP plant provides heating and hot waterservices to all the flats, the shops and thecommunal laundry. It provides electricity forlighting and lifts in the communal areas of thehigh-rise block of flats, for the shopping mall andthe basement car park, and for the plant room.No electricity is exported.

RESULTS

The Cruddas Park community heating and CHPscheme is successful, largely because it is used toprovide heat and electricity for two types of building, each with high demands at differenttimes of the day. The shopping mall has a highdemand during the working day, whereas the flatsrequire most heat and electricity at either side of this period. This means that the system runs to itsfull potential for longer periods, therebymaximising its efficiency.

The use of the citys waste as fuel has theadditional benefits of reducing the need for landfillsites, the costs associated with landfilling andcutting the use of fossil fuels.

Overall, the scheme has:s reduced the cost of providing heat and hot

water for Council tenants. This saves theCouncil money as all tenants in the city pay aflat rate for heat

s provided cheap power for communal areas of the flats and for the shopping mall, the car

park and the laundrys reduced the need for landfill sitess reduced the use of fossil fuelss reduced CO 2 emissions, equivalent to

100 tonnes of carbon each year.

The investment in the CHP scheme is expected tobe recovered in just over five years.

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Capital cost 86 000

Annual maintenance costs 4295Calculated annual fuel saving 21 266Calculated net annual savings 16 971Payback 5.1 yearsEstimated carbon saving per year 100 tonnes

DATA TABLE


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CASE STUDY 3 ST ANDREWS, LEICESTER


BACKGROUND

St Andrews is made up of several four-storey blocksof flats and maisonettes in the centre of Leicester.It consists of 240 dwellings and a care home.

In 1991, Leicester City Council replaced StAndrews 20-year-old coal-fired boiler plant andconverted to natural gas-fired plant. At the sametime the council asked Lincoln Green Energy toundertake a feasibility study to ascertain whetherCHP was a viable option.

Following the study, the Council decided to goahead with the installation of CHP, and the workwas completed in 1994.

IMPLEMENTATION

The scheme was partly funded under the EnergySaving Trusts (ESTs) residential CHP pilotprogramme.

The CHP plant was installed in series with a newgas-fired boiler. It preheats a quantity of the returnwater before passing it back to the main boiler

plant. The central boiler plant provides heatingthrough the winter via the buildings original

radiators, and serves DHW cylinders in all of the flats throughout the year.

The CHP plant provides the landlord withelectricity at St Andrews for lighting in communalareas, lifts and the plant room pumps. Electricity isalso exported across the grid to two local authorityleisure centres. The Council now plans also to sellthe electricity to tenants.

RESULTS

This scheme is very successful. By integrating thecommunity heating scheme with the supply of electricity to the two leisure centres, longerrunning hours have been achieved for the CHPplant. This has helped to increase savings andreduce the payback period.

It has saved nearly 48 000 per year for theCouncil. The system achieved a payback period of just over three years.

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Capital cost 128 290Annual maintenance costs 10 053Annual fuel saving 47 986

Net annual savings 37 933Payback 3.4 yearsEstimated carbon saving per year 55 tonnes

DATA TABLE


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CASE STUDY 4 GILES CLOSE FLATS, BIRMINGHAM


BACKGROUND

Giles Close Flats, three blocks of 48 flats built inthe 1960s, were refurbished in the early 1990s.The original heating for the flats was an off-peakelectric under-floor system and the flats were cold,expensive to heat and suffered from condensationand mould. Birmingham City Council chose toreplace this system with community heating, whichutilised CHP.

The Council already used CHP at a leisure centrenear to Giles Close. The plant provided heat andpower to the centre and the Council was verypleased with the way it functioned. AssociatedHeat Services (AHS) (now Dalkia Utilities Servicesplc), a private contractor, owned and operated theplant and this reduced the Councils maintenancecosts. Moreover, AHS provided heat and electricityat very competitive prices. The Council thereforedecided to install community heating at Giles Closeand to extend the CHP plant to serve the flats.

IMPLEMENTATION

Because the Council would buy more heat from

them, AHS paid for the extension of the pipeworkfrom the leisure centre CHP plant to the flats, and foran additional boiler house to provide top-up heat.

The Council installed distribution pipework in theflats, radiators, heat meters and token paymentsystems, and a heat exchanger in each tower block.The Governments Green House Programme (nolonger running) funded part of this work.

RESULTS

The use of community heating with the leisurecentre CHP has been very successful. The benefitsinclude the following.s Tenants can now heat their flats to a

comfortable level and always have hot wateravailable. The average temperature in the flatshas increased from 13C to 18C.

s Heating costs have been cut, saving tenants46 per year.

s There are fewer voids and transfer applications.s Maintenance costs have been reduced.s The local authority gains income of 88 per

dwelling annually from the charges for fuel.This contributes to the refurbishment andmaintenance costs of the dwellings.

s The environment has benefited from anannual reduction in CO 2 emissions, equivalentto 30 tonnes of carbon.

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CHP capital cost NilCHP maintenance costs NilHeating system installation cost 602 000

Tenants total annual fuel saving 6624Councils annual incomefrom fuel sales 12 672Payback Not applicableCarbon saving per year 30 tonnes

DATA TABLE


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FURTHER INFORMATION


CONTACTS FOR RELATED INFORMATION OR

SERVICES

Combined Heat and Power Association

Grosvenor Gardens House, 35-37 GrosvenorGardens, London SW1W 0BS.Tel 0171 828 4077. Fax 0171 828 0310

Energy Saving Trus t

21 Dartmouth Street, London SW1H 9BP.Tel 0171 222 0101. Fax 0171 654 2444

The following Best Practice programme publicationsare available from BRECSU Enquiries Bureau.Contact details are given on the back cover.

General Information Reports

23 District heating and cooling: an IEAimplementing agreement

50 Unlocking the potential financing energyefficiency in private housing

51 Taking stock private financing of energy

efficiency in social housing

Good Practice Case Studies

80 Rejuvenation of community heating pipework refurbishment in Manchester

81 Community heating in Sheffield82 Consumer connection to community heating

in Sheffield121 Energy efficient refurbishment of high rise

large panel system housing five case studies312 Community heating in Nottingham: an

overview of a rejuvenated system313 Community heating in Nottingham: domestic

refurbishment314 Community heating in Nottingham: pipework

refurbishment

Good Practice Guides

176 Small-scale combined heat and power forbuildings

182 Heating system option appraisal a managers guide

187 Heating system option appraisal an engineers guide for existing buildings

234 Guide to community heating and CHP.Commercial, public and domestic applications

240 Community heating a guide for housingprofessionals (to be published by BRECSU)

267 Combined heat and power in hospitals (to be

published by BRECSU)

New Practice Final Profile

39 Combined heat and power for communityheating

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DETR ENERGY EFFICIENCY BESTPRACTICE PROGRAMME PUBLICATIONS


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Energy Co nsumption Guides : compare energy use inspec ific proces ses , operations, plant and building types.

Go od P ractice: promotes proven energy efficient techniquesthrough Guides and Cas e Studies.

New P rac tice: monitors first commercial applications of new energy efficiency mea sures.

Future P rac tice: reports on joint R&D ventures into new

energy efficiency mea sures.Ge neral Information: describes concepts and approachesyet to be fully established as good practice.

Fuel Efficiency B oo klets: give deta iled information onspecific technologies and techniques.

Introduction to Energy Efficiency: helps new energy manag ersunderstand the use a nd co sts o f heating, lighting etc.

Industrial projects conta ct:Energy Efficiency Enquiries Bureau

ETS UHarw ell, Oxfo rdshireOX11 0RATel 01235 436747Fax 01235 433066E-mail [email protected]

Buildings-related projects conta ct:Enquiries Bureau

BRECSUB REGarston, Watford WD25 9XXTel 01923 664258Fax 01923 664787E-mail [email protected]

Internet BR ECS U http://ww w bre co uk/brecsu/

The Department of the Environment, Transport and the Regions Energy EfficiencyBest Practice p rogramme provides impartial, a uthoritative information on energy e fficiencytechniques and techno log ies in industry a nd b uildings . This information is d iss eminatedthrough publica tions, videos and softwa re, tog ether with seminars, workshops a nd otherevents. P ublica tions w ithin the Be st P ractice programme a re show n oppos ite.

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