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Heat Network
(Metering and Billing)
Regulations 2014
Guidance for Estimating Heat Capacity/
Generated/ Supplied
January 2016
Introduction
The aim of this guidance is to assist heat suppliers in providing information under Regulation 3 of the Heat Network (Metering and Billing) Regulations 2014, Duty to notify. Specifically, Regulations 3-(1)(b)( i), (ii) and (iii). Templates have been made to aid with these notifications; this guidance refers to questions 17, 18 and 19 in the single notifications template or questions 18, 19 and 20 in the multiple notifications template.
An associated spreadsheet, the Heat Estimator, has been created with this guidance to further aid with calculations. Each worksheet in the Heat Estimator corresponds to the numbered methods described in this document. The Data worksheet is left visible so users can understand which values are being used.
This guidance has been created in order to support the broadest range of heat suppliers possible, it does not have to be used in order to comply with the legislation. A more thorough evaluation can be made but this guide shows an acceptable standard. Regulatory Delivery may ask a heat supplier to explain how values have been determined.
Page | 2Shower Project July 2012
Guidance for Estimating Heat Capacity/ Generated/ Supplied
1. Estimated total installed heating/ hot water capacity (kW)
Heat Capacity is the maximum instantaneous output of a heat generator; it is a specification of the generator. Heat capacity is a measure of power and is measured in kilowatts (kW). Heat generated/ supplied over a time period is a measure of energy and is measured in kilowatt-hours (kWh). For example if a 20kW capacity boiler ran at maximum capacity for 2 hours then it would generate 40kWh of thermal energy.
Small domestic gas powered boilers range from about 4kW to 20kW, larger domestic boilers may have capacities up to 70kW. For commercial or industrial use, it is usual to run multiple boilers. If you have multiple heat generators, the total capacity is the sum of the individual capacities.
Some older boilers will state British Thermal Units per hour (BTU/hour) instead of kW.
1BTU ≈0.00029 kWh(Energy )1BTU /hour ≈0.00029kW (Power)
Heat Network (Metering and Billing) Regulations 2014 Page 3 of 9
The Heat Capacity (sometimes called “Maximum Power Output”) is normally printed on the boiler directly but if not, it will be available in the technical specifications or manual. Alternatively, a database of heat generator specifications is available here:
http://www.ncm-pcdb.org.uk/sap/searchpod.jsp?id=17,
Note: If your network is shared with another heat supplier, Regulatory Delivery advises that an arrangement is made for the primary heat supplier to submit a notification for the network which encompasses both of the heat suppliers’ information (i.e. total number of final customers).
If this is not possible, then both parties must make their own notification. In this case, if you are not the primary heat supplier please enter ‘0’ for the Estimated Total Installed Heat/Hot Water/Cooling Capacity and leave a covering note including your primary heat supplier’s name and postcode.
Guidance for Estimating Heat Capacity/ Generated/ Supplied
2. Estimated total heat/ hot water generated per calendar year (kWh)
Heat Generated is the heat input into the network over 12 months (not the amount of fuel being used).
Please use the table below to determine the appropriate method to estimate heat/ hot water generated.
Meter fitted on output of Heat Generator?
Use method:
2.1 2.2
As an alternative to using the Heat Estimator to estimate Heat Generated per calendar year, the calculation can be done manually using the appropriate method below. All energy contents and densities are based on the Higher Heating Value (HHV) also known as the the Gross Calorific Value (Gross CV).
2.2.1. Natural gas
The Heat Generated by a boiler utilising natural gas will be equal to:
Energy content of gasused (kWh)×boiler efficiency (%)
Normally the amount of gas used is measured as energy (kWh) but if only the volume is measured (m3) then the calorific value of the gas will have to be included:
Volumeof gasused (m3 )×GrossCV ( kWhm3 )×boiler efficiency (%)
Heat Network (Metering and Billing) Regulations 2014 Page 4 of 9
Method:2.1. This would be measured by a heat meter placed on the output of the heat generator.
2.2. If there is no appropriate meter fitted, the heat generated per calendar year can be estimated through energy put into the heat generator over a year, multiplied by the heat generator efficiency. This can be done using the Heat Estimator .
Note: If you are not the primary heat supplier and are submitting your own notification, please enter ‘0’ for the Estimated Total Heat/Hot Water/Cooling Generated and leave a covering note including your primary heat supplier’s name and postcode.
Guidance for Estimating Heat Capacity/ Generated/ Supplied
2.2.1. Natural gas (cont.)
The volume of gas used will be measured by a gas meter on the system or taken from an accurate bill.
The gross calorific value of the natural gas depends on its methane content, typically around 97%i, this would equate to about 10.91kWh/m3 ii or 0.3089kWh/ft3
The boiler efficiency should be found on the technical specifications of the boiler, it would be expected to be around 85% iii for a modern condensing boiler.
2.2.2. Oil
The Heat Generated by a boiler utilising heating oil will be equal to:
Volumeof oil used ( l)×GrossCV ( kWhl )×boiler efficiency (% )
The gross CV of oil will be about 10.88kWh/litre iv v An oil burning boiler efficiency should be found on the technical specifications of the boiler.
Older boilers will have efficiencies of around 70% and new condensing oil fired boilers have efficiencies of about 92% vi
2.2.3. Solid Fuel including Biomass and LPG
The Heat Generated by a boiler utilising solid fuel will be equal to:
Mass of fuel used (kg )×GrossCV ( kWhkg )×boiler efficiency (%)
The gross CV of the biomass will depend on what fuel is being used. Common solid fuels and their associated specific energies are detailed in the table below. vii
Fuel Gross CVkWh/kg
Domestic wood 4.14
Wood pellets 4.64
House coal 8.36
Anthracite 9.53
LPG 13.72
A solid fuel boiler efficiency is expected to be around 80% viii
Heat Network (Metering and Billing) Regulations 2014 Page 5 of 9
Guidance for Estimating Heat Capacity/ Generated/ Supplied
2.2.4. Biogas
The Heat Generated by a boiler utilising biogas will be equal to:
Volumeof gasused (m3 )×GrossCV ( kWhm3 )×boiler efficiency (%)
The gross CV of the biogas depends on its methane content, typically around 60 and 68% for household waste and agrifood respectively. This would equate to about 6.42kWh/m 3
(0.1818kWh/ft3) for biogas from household waste and 7.28kWh/m3 (0.2061kWh/ft3) for biogas from agrifood.
Biogas boilers are expected to about 75-90% efficient. ix
2.2.5. Electricity
The Heat Generated by an electric boiler will be equal to:
Electrical energyused ( kWh)×boiler efficiency (% )
Electrical energy used will be measured by an electricity meter on the system. The boiler efficiency should be found on the technical specifications of the boiler, it would
be expected to be around 90-100% x
Heat Network (Metering and Billing) Regulations 2014 Page 6 of 9
Guidance for Estimating Heat Capacity/ Generated/ Supplied
3. Estimated total heat/ hot water supplied per calendar year (kWh)
Heat Supplied is the total amount of heat used by the customers of the system per calendar year. It should be lower than the Heat Generated due to the heat losses between the generator and the final customers.
Please use the table below to determine the appropriate method to estimate heat/hot water supplied per calendar year.
Individual meters fitted for each final customer?
Good knowledge about network efficiency?
Good knowledge about customer consumption?
Use method:
3.1 3.2 3.3 3.4
Heat Network (Metering and Billing) Regulations 2014 Page 7 of 9
Method:
3.1. This would be the sum of the metered consumption of each final customer for the year. A table is available in the Heat Estimator to facilitate this.
3.2. If no appropriate meters are fitted but you have good information about the expected efficiency of your network, the Heat Supplied per calendar year would be approximately:
Heat Generated per year (kWh )× ExpectedNetwork Efficiency (%)This can be done using the Heat Estimator. The expected network efficiency should include heat and head losses in pipes to the buildings and throughout the buildings; this will vary
depending on the size of the network, size/location of pipes, insulation, ambient conditions, maintenance etc.
3.3. If you do not have good information about the expected network efficiency, the expected annual consumption of each property on the network should be summed. A table is available in the Heat Estimator to facilitate this.
3.4. If you do not have good information regarding the efficiency of your network or the consumption of the properties on the network, use the energy demand benchmarks laid out in Assessing the cost effectiveness of individual metering: Energy Demand benchmarks. This can be done using the Heat Estimator.
Guidance for Estimating Heat Capacity/ Generated/ Supplied
As an alternative to using the Heat Estimator to estimate Heat Supplied per calendar year, the calculation can be done manually using the method below.
The energy demand benchmarks are laid out in Assessing the cost effectiveness of individual metering: Energy Demand benchmarks . Benchmarks are based on space heating and hot water demand; it is assumed that 21% of overall heating demand is attributed to hot waterxi.
The estimated Heat Supplied for a domestic property is the sum of the annual domestic energy demand of each property on the network from Table 1. The consumption for each domestic property is categorised by age and type, this is then adjusted by regional weather correction factors from Table 3.
Example: A block of 6 flats built in 1965 in North East England (+11%)
8 ,653 kWh×6 flats× (1.0+0.11 )=57,629 kWh
The consumption for each non-domestic property type is categorised by use and floor space on Table 2, then adjusted for regional weather correction (this should be applied to only the proportion of the benchmark related to degree days).
Example: A general office (fossil-thermal prorated to degree days= 55%) in East Anglia (+4%) with a floor space of 90m2
120 kWhm2×90m2× (1.0+(0.55×0.04 ) )=11,038 kWh
Heat Network (Metering and Billing) Regulations 2014 Page 8 of 9
Note: Energy Demand Benchmarks will not be appropriate for all networks, if method 3.4 produces a higher heat supplied value than heat generated, please revert to using method 3.2.
Guidance for Estimating Heat Capacity/ Generated/ Supplied
Heat Network (Metering and Billing) Regulations 2014 Page 9 of 9
i http://www.biogas-renewable-energy.info/biogas_composition.html 24/02/2015iihttps://www.gov.uk/government/uploads/system/uploads/attachment_data/file/447648/DUKES_2015_Annex_A.pdf 18/08/2015iiihttps://www.gov.uk/government/uploads/system/uploads/attachment_data/file/424254/heat_networks.pdf 26/03/2015iv http://physics.info/energy-chemical/ 03/06/2015v http://www.engineeringtoolbox.com/fuels-higher-calorific-values-d_169.html 18/08/2015vi http://www.which.co.uk/home-and-garden/heating-water-and-electricity/guides/how-to-buy-the-best-boiler/oil-boilers/ 03/06/2015viihttps://www.gov.uk/government/uploads/system/uploads/attachment_data/file/447648/ DUKES_2015_Annex_A.pdf 18/08/2015viii http://www.energysavingtrust.org.uk/domestic/content/our-calculations 24/02/2015ix Peter Frost and Stephen Gilkinson, 27 MONTHS PERFORMANCE SUMMARY FOR ANAEROBIC DIGESTION OF DAIRY COW SLURRY AT AFBI HILLSBOROUGH, June 2011x
xi
Contact Details
Enforcement AuthorityRegulatory Delivery Stanton AvenueTeddingtonLondonTW11 0JZ
Enquiry Telephone: 020 8943 7227
Website: www.gov.uk/heat-networks
Email: [email protected]
Enquiry System: www.rohs.bis.gov.uk/enquiry.aspx
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