Heat pumps have a “critical role” to play in London reaching net zero according to a new report from The Carbon Trust.

The report, which was commissioned by the Mayor of London, is designed to help guide local authorities, social housing providers and others considering a heat pump retrofit.

Retrofitting will be of significant importance for London as at least 80% of its buildings are expected to still be standing in 2050, with a need to improve energy efficiency in buildings in order to deploy heat pumps at scale.

The report also stressed the importance of good practice system design, which it said will be “essential” for effective heat pump deployment.

Heat pumps are, however, the “primary technology choice for decarbonising heat in existing buildings” due to their efficiency, with The Carbon Trust stating that this, combined with the ongoing rapid decarbonisation of the grid, means the technology has the potential to deliver CO2 savings of 60-70% compared to conventional electric heating and 55-65% compared to an A-rated gas boiler.

Air conditioners (Image: Todd Morris/Flickr)

Air conditioners (Image: Todd Morris/Flickr)

They will also reduce fuel bills compared to conventional electric heating, but they could increase fuel bills compared to gas unless paired with energy efficiency, best practice system design and flexible use of heat.

This is despite the high upfront cost of heat pumps, although the report did continue to say that many building types will require additional up-front financial support.

However, the lifetime financial case for heat pump retrofit is already strong in some building types, according the report, citing examples of electrically heated buildings, buildings with a high cooling demand and buildings that already require major renovations, which are all building types that should be prioritised for heat pump retrofit.

Due to these findings, The Carbon Trust has created an action plan for heat pumps, including the recommendation to re-balance gas and electricity energy taxation to incentivise low carbon heating.

“As always, heat pumps are not a silver bullet solution, which is why we have provided a suite of policy recommendations, including investment in energy efficiency in buildings and flexibility in the energy system,” Tom Delay, chief executive of the Carbon Trust, said.

Read more: Current