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Notes
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Calculation is based on:
- Heat pump on offer is a package of 7KW air source heat pump with designed efficiency (SCOP) of 3.48, radiator upgrades, hot water tank and installation.
- Typical upfront price of £3,999 includes Green home grant discount of £5000, is for a property in the South of the UK with annual heat demand of 13,903 kWh consumption for heating and hot water, at least 150mm insulation and built between 1960-1980.
- Our expert installer will provide a more accurate assessment of heat pump cost & savings based on your individual needs and house type
- Boiler cost of £3,324 from recent govt study where we assume a non-combi boiler of 24KW and boiler efficiency of 84%
- It does not differentiate between bedroom sizes so its an average across all property types: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/913508/cost-of-installing-heating-measures-in-domestic-properties.pdf
- Heat pump lifetime is usually 15-20 years compared to boiler of 10 years
- Energy & carbon price assumptions from https://energysavingtrust.org.uk/about-us/our-calculations
- Car emission from UK Government GHG Conversion Factors for Company Reporting 2020, assuming 10,000 miles for an average size petrol car
- RHI subsidy of £7,068 (based on 10.1p/kWh)
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Heathrow to Madrid, Spain is 1243 km one way.
BEIS - UK Government GHG Conversion Factors for Company Reporting 2020 - Air Travel with RF factor included states 0.378394 tonnes of CO2 per economy passenger for a return flight.
The carbon difference between a heat pump and boiler is calculated as:
A - 13,903 kWh of energy demand for heating and hot water
B - 3.48 heat pump designed efficiency
C - new boiler efficiency of 84%
D - Gas fuel emissions of 208 gCO2/kWh
E - Electricity fuel emissions of 277 gCO2/kWhGas CO2 = (A/C*D) = 3.44 tonnes
Electricity CO2 = (A/B*E) = 1.11 tonnes1-(1.11)-(3.44) = 68%