Nesta and WWF Scotland commissioned analysis from Cambridge Architectural Research (CAR), building on a study that CAR had carried out for WWF Scotland.

In this previous work, CAR explored the lowest-cost way to decarbonise heating in typical Scottish homes, modelling a series of 12 home archetypes (and a further set of sub-archetypes with constraints like limited space or heritage designation) which together represent the diversity of the Scottish housing stock. Energy use, carbon emissions and upfront and running costs of different heat pump and energy efficiency measures (for many of the archetypes this is simply draft proofing) were identified that would provide the most cost-effective route to decarbonisation.

For this latest analysis, we carried over those same heat pump and energy efficiency combinations and explored what the running costs and total costs of ownership for a heat pump could be in 2028. In particular, the analysis allows us to look at results across the modelled Scottish housing stock, giving a clearer idea of how many and which homes would see a benefit from switching to heat pumps.

A key factor affecting heat pump running costs is the price of electricity relative to gas prices. Electricity is more expensive in the UK than in any EU country and the previous CAR/WWF report highlighted how changing some of the current policies that make electricity more expensive than gas would have an important bearing on the costs of running a heat pump in Scotland. With this work, we wanted to explore the impact of future electricity price trends on heat pump ownership and investigate what extra energy bill savings could be made for homes by using time-of-use tariffs.