Heat Pump Emmission Savings

Heat pumps offer significant CO2 emission savings compared to traditional heating methods. Air source and ground source heat pumps can achieve seasonal coefficients of performance (SCOP) around 300%, reducing emissions to 0.069 kg CO2 per kWh, compared to 0.208 kg CO2 per kWh from conventional UK heating sources, an average reduction of 67%. By replacing fossil fuels with heat pumps, homeowners can substantially cut their carbon footprint and contribute to environmental sustainability.

General Emmission Savings

SCOP = Seasonal Coefficient of Performance

Emmission Savings Based from UK Installations 2022-2023

The installation of heat pumps in the UK during 2022-2023 led to substantial CO2 emission savings. Air source heat pumps displaced mostly gas (49%) and oil (20%), resulting in weighted CO2 savings of 0.149 kg CO2e/kWh. Ground source heat pumps and shared ground loop systems also contributed to reductions, with weighted savings of 0.171 kg CO2e/kWh and 0.208 kg CO2e/kWh respectively. On average, households saved 0.176 kg CO2e per kWh used for heating, a reduction of 72%.

Source Boiler upgrade scheme Source RenSMART - Fuels KWH and CO2

Air Source Heat Pumps

Fuel type displaced	Installations replacing fuel type	Percentage replacing fuel type	Weighted kg CO2e / kWh
Gas	8,905	49%	0.09727987765
Oil	3,690	20%	0.05240332095
None	3,033	17%	0
Direct electric	1,709	9%	0.018
Liquefied Petroleum Gas (LPG)	576	3%	0.0069
Coal	210	1%	0.0037
Other	172	1%
Unknown	13	0%
Total	18,308
		82%	Replacing Known Fuel Source
		0.218	Weighted kg co2e / kWh
		0.149	Saving kg co2e / kWh

Ground Source Heat Pumps

Fuel type displaced	Installations replacing fuel type	Percentage replacing fuel type	Weighted kg CO2e / kWh
Gas	63	11%	0.02299270073
Oil	135	25%	0.06405109489
None	295	54%	0
Direct electric	33	6%	0.01204379562
Liquefied Petroleum Gas (LPG)	9	2%	0.003777372263
Coal	9	2%	0.006076642336
Other	4	1%
Unknown	0	0%
Total	548
		45%	Replacing Known Fuel Source
		0.240	Weighted kg co2e
		0.171	Saving kg co2e / kWh

Shared Ground Loop Ground Source Heat Pumps

Fuel type displaced	Installations replacing fuel type"	Percentage replacing fuel type	Weighted kg CO2e / kWh
Gas	2	13%	0.02666666667
Oil	2	13%	0.03466666667
None	9	60%	0
Direct electric	0	0%	0
Liquefied Petroleum Gas (LPG)	0	0%	0
Coal	2	13%	0.04933333333
Other	0	0%
Unknown	0	0%
Total	15
		40%	Replacing Known Fuel Source
		0.277	Weighted kg co2e
		0.208	Saving kg co2e / kWh

The average house that installed a heat pump in 2022-2023 saved 0.176 kg co2e per kWh they used for heating. A reduction of about 72%.

Weighted CO2e Savings Equation

The column "Weighted kg CO2e / kWh" indicates the average amount of carbon dioxide equivalent emissions saved per kilowatt-hour of energy used by heat pumps. This figure is weighted based on the specific proportions of different heating fuels (such as gas and oil) that heat pumps replace, providing a comprehensive measure of the overall emissions reduction achieved by switching to heat pumps.

The "Weighted kg CO2e / kWh" can be calculated using the following equation:

Weighted kg CO2e / kWh = ( Σ (proportion of fuel type × CO2e savings per kWh for that fuel type) ) / total energy replaced by heat pumps