5_determination of energy savings

8/13/2019 5_determination of Energy Savings

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DETERMINATION OF ENERGY

SAVINGS

Prepared by

Duan Gvozdenac and Miroslav Kljaji

Project: Regional training on planning and monitoring

energy efficiency measures in the constructing sector

Podgorica, Tiran, Sarajevo i Banja Luka, October December, 2013.


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Determination of Energy Savings

Energy is paid in money but it is measured in energy units

(kWh, kJ). There is direct dependence between the price paid

for energy and its consumption and it is stated in the unit priceof energy. This price is mostly determined by external factors

and the owner of a factory, a house or an apartment cannot

affect it. He/she can choose the type of energy carrier which

will be used for his/her needs and thus affect overall energy

costs. The efficient use of purchased energy is under his/her

full control and he/she can do a lot in that respect. How?

You cant manage what you dont measure


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Determination of Energy Savings

Measuring parameters of energy flows provides conditionsfor their control.

If criteria of this control are established (for example,

minimum energy consumption or minimum pollution of theenvironment or maximum security of energy supply or

achieving maximum preset comfort in an air conditioned

room, etc.), it is possible, then, to achieve optimum control

of the system with preset conditions.


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0

200

400

600

800

1000

1200

1400

1600

Jan -01 Feb-01 Mar -01 Apr-01 May-01 Jun-01 Jul-01 Aug-01 Sep-01 Oct -01 Nov-01 Dec-01

Month

Electricity

Heat Energy

Energ

yConsumption[MWh/m]

Child

Water

Energy

Example of Energy Consumption during a Year


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MonthlyElectricity

Consumption[MWh/m]

Time [h]

New Load

Duration Curve

Current Load

Duration Curve

0 1000 2000 3000 4000 5000 6000 7000

0

200

400

6000

800

1000

1200

1400

16001800

Load Duration Curve Electricity


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Energy efficiency projects are in their core offering the

increase of the degree of effectiveness of some energy

transformation.

This is achieved by changing procedures of managing theenergy plant, by replacing the part or the whole technology,

etc.

No matter what is in question and what kind of change is

made, it is necessary to provide continuous monitoring of

energy flows in the energy plant.

Monitoring Energy Flows


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The achieved effects are determined by comparing measuredvalues of energy consumption before and after the application

of one or more measures to increase energy efficiency. The

activities under the M&V procedures are:

Installation, calibration and maintenance of measuring

devices,

Collection, processing and analysis of data,

Development of a calculation method and establishment of

reliable assessments, Calculations with measured data, and

Reporting to all relevant stakeholders and verification of

reports by a third party, if there is a need for that.



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Measurements that are carried out within the M&V should be

differed from the measurements related to the process

management or measurements that are occasionally done

during preliminary and detail energy audits. The main purpose

of the M&V is as follows:

To reduce energy consumption. It is well known that it is

not possible to manage something that is not measured.

Measurement of energy consumption provides building

managers not only with valid information about theappropriateness of energy systems but also about the

effects of possibly undertaken measures to increase energy

efficiency.



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To stimulate financing of projects for energy efficiency

increase. A good M&V PLAN increases transparency andcredibility of reports on achieved effects. The existence of

the M&V Plan can also raise thrust of investors and potential

donors in energy efficiency projects.

To improve design solution, plant and maintenance.

Good M&V helps managers to disclose and lessen problems

related to maintenance and plant running and provides

feedback information for planning future investments.

To manage energy balance. Even in cases whenenergy

consumption is not planned, the M&V techniques enablemanagers to manage energy use in a much better way. The

M&V techniques provide opportunities to notice and explain

possible deviations from the balance and to introduce

corrections resulting from changed operating conditions.



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To increase the value of the project by collecting credits

for reduced emissions. The calculation of reduced GHGemissions adds value to the project if the project is

implemented under the mechanisms of the Kyoto Protocol.

The use of the M&V Plan for determining energy effects also

contributes in the growth of credibility of reports on reducedemissions.

To improve understanding of energy management as an

instrument of national energy policy. The M&V techniques

are a powerful tool for the promotion of social awareness on

energy efficiency and reduction of GHG emissions. Good M&V

practice emphasizes social benefits offered by proper energy

management such as the improvement of public health and the

protection of the environment.



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M&V Plan and Report on Achieved Effects

The process of developing the M&V Plan should be carried outsimultaneously with the preparation of the project for the

implementation of a measure or measures to increase energy

efficiency. The measurement processes and verifications should

include the following steps:

Analysis of needs of users of planned reports.If the priority

to the user is to control total costs, the best method is the one

that involves the entire building. If the result of a specific

measure to increase energy efficiency is important to the user,it is necessary to select measurements that enable

determination of some specific energy indicators. Such cases

arise when it is necessary to check some technology in order

to repeat similar projects in the factory.


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M&V

0

20

40

60

80

100

120

Jan-10

Mar-10

May-10

Jul-10

Sep-10

Nov-10

Jan-11

Mar-11

May-11

Jul-11

Sep-11

Nov-11

Jan-12

Mar-12

May-12

Time

Energ

y

Reporting PeriodBasic Period

Increased

Production

EEM

Implementaion

Saving or

Avoided

Energy Use

Calculated ConsumptionCorresponding to Conditions

without EEM Implementation

Example of Energy Consumption Diagram


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Preparation of the plan for reading measured

values

Modern technology provides opportunities for automatic

reading of measured values. However, this does not mean that

it is also compulsory. Therefore, it is necessary to select anoptimum plan for reading which can also be manual. The goal

is to obtain reliable measurement values.


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Data processing and reporting

The whole M&V procedure is carried out to obtain reliable data

about achieved savings in energy and water consumption. Dataprocessing is done according to previously verified procedure

and it can be manual or automatic. The report on achieved

results should be forwarded to several addresses and therefore,

it should be prepared with that in mind.

For example, if it is sent to the top management, it should be,

then, very simple and contain only data related to the final

financial effect of the measure for energy efficiency increase. If

the repot is intended for technical management of the facility in

which the plant is located, the report should contain technical

indicators enabling evaluation of not only achieved savings but

also of the quality of operations of the whole plant and

monitoring of parameters affecting functionality


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Verification Plan

When planned savings in energy consumption are determined

and possibly proved, it is necessary to establish the procedure in asystematic way for constant verification of measurement data and

calculations and to plan necessary actions when it comes to

deviations. By all mean, it is necessary to envisage some sort of

tolerance within which measured values are still satisfactory and

it is considered that the effects of implemented EEM are

acceptable.

However, if deviations are not within planned limits, the reason

for that should be immediately sought and measures undertaken

to return observed parameter within acceptable limits. The

following Figure shows an example of measurement results and

their verification.


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Energy

Time

Allowed

Deviation

Planned Energy

Consumption after EEM

Implementation

Unexpected

ConsumptionTrend. Immediate

Action to Remove

Defect

Expected

Saving

Baseline Energy

Consumption

Baseline Period Period after EEM Implementation

Examples of Monitoring and Verification


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Analysis of financial effects in the lifecycle of

applied EEM

The M&V is a permanent process which is conducted in the

whole period of the project lifecycle. In addition to physical

decrease of energy consumption, it is important to determine

financial flows.

Namely, energy prices are changing during time unfortunately

almost always up and not always in the proportion. Thus, it is

possible that the effect of physical reduction of energy

consumption does not need to correspond always to adequate

effect financially.


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The following Figure shows the basic measurement points

and the values to be measured in the case of a steam boiler.

The boxes in gray background represent values that are not

necessary to be measured.

For example, the temperature of steam (M2) should bemeasured only in case of superheated steam. Or, if the steam

flow is measured with sufficient accuracy, it is not necessary

to measure the flow of feed water although this value is

often measured.

Boilers M&V.


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Boundary of System

M2

mS[t/h] =pS[bar] =

tS[oC] =

Steam

M1

tFW[oC] =

mFW[m3/h] =

ConFW[S/cm] =

Feed Water

M3

M4

mG[kg/h] =

GCV [MJ/kg] =

Fuel

tA[oC] =

Air

tPS[oC] =

CO [ppm] =

O2(vol) [%] =

Flue Gasses

M5

CondBW[S/cm] =

Boiler Water

M7

M6

mBD[t/h] =

Blowdown

M8

tsurface[oC] =

Radiation Losses

Typical Measuring Points for Boilers

Frequency and Scope


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MONITORING

PARAMETERPURPOSE

Frequency and Scope

< 20 t/h of steam20 100 t/h of

steam

Liquid Fuels

Calorific value Calculation of heat input.No checking. Valuesgiven by the supplier

can be used.

Density and sulfurportion for each

delivery.

Fuel composition

(Fuel distributioncompanys certificate )

Possible negative effects

on heat transfer surfaces

and emissions ofcombustion products.

No checking. Values

given by the supplier

can be used.

Annual control.

Consumption Calculation of heat input.Daily measurement

and control.

Continuous

measurement and

control

Viscosity Regulation of burner. From time to time.For each fuel

delivery.

Combustion

product

temperature

Calculation of energy

efficiency of heat losses

with combustionproducts.

Continuous

measurement and

control.

Continuous

measurement and

control. Automaticregulation

MONITORING Frequency and Scope


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MONITORING

PARAMETERPURPOSE

Frequency and Scope

< 20 t/h of steam 20 100 t/h of st.

Gaseous Fuels

Calorific value Calculation of heat input.

No checking. Values

given by the suppliercan be used.

Density and sulfur

portion for eachdelivery.

Fuel contents

Possible negative effects

on heat transfer surfaces

and emissions of

combustion products.

No checking. Values

given by the supplier

can be used.

Annual control.

Consumption Calculation of heat input.Daily measurement

and control.

Continuous

measurement and

control.

Combustion

producttemperature


efficiency of energy withcombustion products.

Continuous

measurement andcontrol.

Continuous

measurement and

control. Automaticregulation

Combustion

products analysis

Calculation of efficiency

(by using portion of O2;

and due to incomplete

combustion by usingportion of CO).

Daily analysis.

Automatic regulation

is desirable

Continuous

measurement and

control. Automatic

regulation


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Frequency and Scope


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MONITORING

PARAMETERPURPOSE

Frequency and Scope


steam

WATER

Supply wateranalysis

Blowdown Measurements pershifts.

Continuous


Supply water

temperature


efficiency.

Continuous

measurement and

control.

Continuous

measurement and

control.

Supply water flowCalculation of steamproduction if flow is not

measured.

Continuousmeasurement and

control.


control.

Fresh water

analysisBlowdown Daily measurements.

Continuous

measurement and

control.

Boiler water

analysisBlowdown.

Measurements per

shifts.

Continuous

measurement and

control.

Temperature of

return condensate

Calculation of supply

water temperature.

Measurements per

shifts.

Continuous


F d S


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MONITORING

PARAMETERPURPOSE

Frequency and Scope


steam

STEAM

Steam flowCalculation of efficiency

and heat energy.


recording or supply

water flow

measurement.

Continuous

measurement

and control.

Steam pressureCalculation of thermal

effect.

Continuous

measurement and

control.

Continuous

measurement

and control.


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Options of M&V Procedures

M&V OptionManner of Calculating

EffectsTypical Application

A.

Measurement of key

parameters

Savings are determined by

measuring key parameters

which define energy

consumption of the system in

which the measure for energy

efficiency increase has been

applied.

The frequency of

measurements is adapted to

expected variations ofmeasured parameters.

Less important parameters

are estimated on the basis

specifications provided by

equipment manufactures or

on the basis of experience.

On the basis of

engineering calculations

of energy consumption ofthe baseline period and

after EEM application.

It is compulsory to

determine CORRECTION

on the basis of operating

conditions of theequipment or plant in

both periods.

Lighting in whichcapacity is the key

parameter. The other key

factor is the number of

operating hours of

individual parts of the

lighting system.


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Effects

Typical Application

B.

Measurement of all

parameters

Savings are determined by

measuring energy

consumption of systemaffected by the EEM

implementation.

Frequency of

measurements is in the

range from short term to

continuous depending onexpected variations of

measured parameters and

on the duration of the

reporting period.

Short term or continuous

energy measurements in

baseline and reporting

periods and/or engineering

calculations by means of

indirect measurement of

energy consumption.

Routine and non-routineadjustments are done

according to the needs.

When using frequency

regulators for the purpose

of pump flow control. Watt

meters measure electricity

every minute.



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C.

Supervision pf the whole

facility

Savings are determined

by measuring energyconsumption of the whole

facility or part thereof.

Continuous measurement

of energy consumption in

the whole facility is used

during the whole reportingperiod.

Annalisa of data by

metering devices inbaseline and EEM

application periods.

Routine and non-routine

corrections are made

according to the needs.

Implementation of the

energy management

program affecting systems

within the building (plant).Monthly measurement of

energy consumption by

meters for electricity and

gas in the course of twelve

consecutive months and

over the whole service lifeof the project.



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D.

Simulation of consumption

measurement

In this case, savings are

determined by simulation

of energy consumption of

the whole facility or partthereof.

This type of M&V is the

only one in new buildings

when there are no baseline

measured values.

Simulation routines areused for adequate

modeling of actual energy

efficiency of systems in the

building (plant).

Simulation of energy

consumption with hourly

or monthly data from

bills (measurement of

final energy consumption

can be used for

redefining input data).

Multi purpose program formanaging energy

consumption in the building

has several systems and does

not have data for the baseline

period.

After the installation of ameasuring device,

measurements are used to

calibrate simulations.

Energy consumption in the

baseline period is determined

by means of calibratedsimulation and it is compared

with the simulation of energy

consumption in the period

after EEM has been

implemented.



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Example 1. Improvement of Boiler Efficiency

Starting points. The contractor hasreplaced the existing boilerin a commercial building with a new more efficient one. In the

offer, annual savings of fuel oil of at least 35,000 is guaranteed

provided the boiler load is the same as in the baseline period

which included the whole heating season. The employer is

obliged to pay for annual savings to the contractor after the

contractor presents the report on savings. The M&V Plan for the

whole period is done together by the contractor and the

employer (Type B).


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As it was already mentioned a company which provides energy

services by proposing EEMs through contracts with guaranteed

energy savings is called an Energy Service Company(ESCO).

The primary purpose of the M&V for contracts with guaranteed

effects often quickly shows the results of energy efficiency

projects. After such analysis and verification of effects, theemployer can undertake running the plant and does not need

permanent relations with the ESCO. The M&V Plan becomes the

part of the contract on guaranteed savings and defines

measurements for determining mutual payments.


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Factors affecting M&V concept.

The hot water boiler isthe only energy device that

uses fuel oil as a fuel. The price of fuel oil according to

which savings will be calculated is 1.10 /l. The

agreement between the contractor and the employerseems to specify the contractors responsibility only

relevant to the improvement of boiler energy

efficiency and not for the load under which the boiler

is used.


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M&V Plan. The control boundary of the system is the hot water

boiler itself. Measurements include measurement of fuel oil

consumption and net delivered heat to the building. Since the

boilers consumption of electricity in relation to the consumption ofchemical energy of the fuel is minimum, electricity consumption is

not included in the energy balance.

Such a plan is an option A in the Table 2.

The buildings owner ordered 241,300 liters of fuel oil for firing the

boiler in that heating season. At the end of the heating season there

were 2,100 liters left in the tanks out of the ordered quantity. The

consumption of fuel oil in the baseline year is 239,200 liters. Theboiler load is determined according to above data after determining

energy efficiency of the existing boiler. This quantity of fuel oil is

considered as accurate as it is determined by measuring the level in

the tanks and confirmed by bills of the fuel oil supplier.


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Energy efficiency or the degree of the boilers effectiveness is

carried out during winter period before the removal of the old

boiler. Winter conditions are needed to ensure sufficient boilerload and thereby obtain reliable figures for the boilers efficiency.

To measure the flow of fuel oil, a turbine flow meter is installed

with the accuracy class of 2%. For measuring delivered heat

energy, a calorimeter is installed of the same accuracy class.

Baseline data are obtained on the basis of independent

measurements in the duration of three weeks at the time when

the average daily temperature was -5 to +5 oC. The same kind of

measurements is also planned after the installation of a newboiler by means of the same measuring devices. This also implies

that the outside temperature is within the same range as in the

case of measuring the efficiency of the old boiler.


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Measurements for the old and later for the new boiler are carried

out by boiler operators on a daily basis during planned three

weeks. Readings of the meter and calorimeter are recorded in a

prepared form available for inspection at any time.The outside temperature is measured automatically and it is

recorded in an independent device. The contractor and the

employer determined together the level of satisfaction of the

external conditions for the execution of tests.

Delivery, installation, putting into operation of the calorimeter

and flow meter for fuel oil, calculations and writing a report on

achieved savings during two months is agreed in a separate

contract worth 5,100. The contractor offered an additional

contract worth 3,000 for the supervision of measurements over

the entire heating season. This additional contract was not

accepted by the employer.


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0.652Reduction of Fuel Oil Consumption 239.200 1 45,700 [l / year]

0.806

Fuel OilSaving 1.10 45,700 50,270 [/ year]

Since the annual consumption of fuel oil is known (239,100 liters),

the expected annual saving is as follows:

The expected financial effect is:

The contractor guaranteed the saving of at least 35,000 and

obviously did not achieve that.


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Example 2. Efficiency of a Lighting System

Starting point. In one school, efficient lighting is installed

instead of old and inefficient lighting. The degree of illuminationremains the same as it is determined that the old lighting

system meets modern standards in terms of illumination.

The School Board has entered into negotiations with a qualified

contractor taking into account a number of programs withmeasures to increase energy efficiency. It is proposed that

payments are based on measured savings according to the price

of electricity at the time of contract signing. The M&V plan

defines, among other things, the manner of calculating savings.

Since users control the lighting system in the school, it is agreed

to implement Option A and to measure key parameters. Key

parameters are the capacity of the lighting system and the

number of operating hours. Details are worked out in the M&V

plan.


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Factors affecting M&V concept.When preparing theM&V Plan, the following facts have been taken into

considerations:

The whole lighting system is supplied by a standard low voltage electricity

grid (220 V) which is used only for the supply of the lighting system. This

fact simplifies the measurement of electricity consumption.

Since the old system of lighting (incandescent light bulbs) affects heat

energy requirements, it is necessary to consider and assess mutual effectsof two energy systems.

The existing lighting system affects also the cooling system. However,

during the hottest months, the school is not used. Therefore, the interaction

between these two systems can be neglected.

The School Board did not accept the contractors proposal to determine the

number of hours of lighting systems operations arbitrarily. Therefore, it is

agreed to monitor operations of the lighting system in the school. This test

should determine the reliable number of hours of the systems operations

during the baseline period and later during the calculation of savings.

M&V Plan The boundaries of the lighting system are determined


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M&V Plan. The boundaries of the lighting system are determined

in such a way to include all light bulbs which are connected to the

grid.

Interactive effect on heating is determined by technical

calculations. It is determined that heat energy required for the

heating system will be increased by 3% after the replacement

of incandescent light bulbs with highly efficient lights. This

refers to the whole heating period. The efficiency degree of the

boiler is 79% and it is determined by an independent test instandard winter conditions.

Other factors, which are used for the preparation of the M&V

Plan include description, location, level of illumination and the

number of operational and burned out light bulbs. The level of illumination is determined arbitrarily by setting up

30 luxmeters (data logger) in classrooms, corridors, dressing

room, etc. The test lasted for two months. The Table 3 gives

some data obtained during the test.


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Location

Portion of

Lighting

Subsystem

in Total

Capacity

[%]

Average Number of

Hours in a Week

[h/week]Assessment of

Annual

Operating Hours

[h/year]Business

Day

Holidaysand

Weekend

s

DressingRooms 5 106 22 4,424

Offices 5 83 21 3,514

Classroom

s61 48 + 6 5 2,172

Amphitheaters

10 31 11 1,354

Halls 10 32 25 1,578

Corridors 9 168 168 8,770


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Result. After the implementation of EEM, measurements are

repeated in all electric circuits as during the test to determine

baseline power. Maximum power is 162 kW with all new lights

turned on. There are no burned out lights. With the samepercentage of 1% for burned out lights, as in baseline period,

peak load is 160 kW (= 162 0.99).

Power reduction relevant for calculations is:

P 288 160 128 kW

Expected electricity saving is:

E 128 2,792 357,376 kW /a


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Saving of power input is 128 kW during ten months and 50% of

that during two summer months. This is totally 1,408 kW for the

whole year.

Thus, total financial effects of electricity consumption for this

EEM is:

N (357,376 0.0510) (1,408 8.79) 30,602 / a

Because of the above change of lights, the boiler for heat energy

production should deliver around 3% more energy during heating

season. It can be estimated that during a typical winter months

electricity consumption for lighting is equal to:

mon

357,376EE 35,738 / a

10


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If it is determined that the consumption of heat energy is

increased (5 months) after the implementation of the EEM by

some 3%, the equivalent of primary energy of natural gas is

equal to:

0.03 35,738 5NG 6,786 kWh / a

0.79

The calorific value of natural gas is 10.5 kWh/nm3 so that

additional quantity of natural gas required for heating purposes

is equal to 646 nm3/year. The monetary value of this amount of

gas is 133.5.

Now, the total net savings is equal to: 30,602 133.5 = 30,468.5

/year.

5_determination of energy savings

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