Low carbon heat technology installed under the voucher segment of the Green Homes Grant is resulting in an annual bill saving of £641,000.
Additionally, the estimated annual energy saving of these installations is 40GWh. For heat pumps specifically, the estimated annual bill saving is £461,9000.
In total, all measures installed under the scheme - which includes insulation and double glazing among other measures - are estimated to save £3.9 million in bills a year.
Energy bills are expected to rise once the next energy price cap comes into effect in April, with research from charity Resolution Foundation estimating that 6.3 million households could experience fuel stress.
Installations of energy saving technologies under the Green Homes Grant have slowed, with delivery in December 2021 83% lower than in November 2021. However, the Department for Business, Energy and Industrial Strategy (BEIS) said this was due to the small number of remaining cases, with the scheme having closed to new applications in March 2021.
In December, there were 430 measures installed, of which 71% were for low-income households. Of these, 123 were low carbon heat installations, with 45 air source heat pumps, one ground source heat pump, nine hybrid heat pumps and 68 solar thermal installations.
In total for 2021/22, there have been 12,432 low carbon heat installations, 4,950 of which were heat pumps and 7,482 of which were solar thermal. Of the heat pump installations, 3,956 were air source, 31 were ground source and 963 were hybrid heat pumps.
Meanwhile, under the Local Authority Delivery of the scheme, there have been 893 low carbon heat installations as of the end of November 2021, 677 of which were air source heat pumps, while there have been no ground source heat pump installations, 19 hybrid heat pumps, 74 solar thermal and 123 electric storage heating installations.
For Phase One of the Local Authority Delivery to the end of November 2021, estimated annual bill savings from heat pump installations totals £220,000, while solar PV is estimated at £190,000.
Earlier this month, British Gas launched a new air source heat pump offering, aiming to hit 20,000 annual installations by 2025.
Meanwhile, the use of heat pumps for flexibility is being trialled by several distribution network operators, including one trial run by Western Power Distribution with project partners SP Energy Networks (SPEN), Passiv Systems, Octopus Energy, SERO Homes, West Midlands Combined Authority, Guidehouse and the Welsh government.
A separate trial is also being run by SPEN and Scottish and Southern Electricity Networks Distribution looking at how operators can react to high electricity demand caused by decarbonised heating systems, using the flexibility of heat pumps and storage to benefit the network.