Residential heating generates 18% of UK carbon emissions, with the majority from natural gas boilers. Decarbonising home heating is critical to achieving Net Zero.

Launched and funded by the Department for Energy Security and Net Zero (DESNZ) and led by Energy Systems Catapult with support from LCP Delta and Oxford Computer Consultants, the Electrification of Heat Demonstration Project sought to understand the technical and practical feasibility, and constraints of a mass rollout of heat pumps into British homes.

Over 700 heat pumps were installed by the delivery contractors into a broad spectrum of housing types. The project has demonstrated that the large-scale rollout of heat pumps is possible within the UK. It has shown that heat pumps can be successfully installed in all the types of property which were tested by the Project. It has also shown that they can operate with good efficiency and provide positive consumer heating experiences.

Scene setting

With 87% of households on the national gas grid – replacing fossil fuel gas boilers with heat pumps can make a substantial contribution to achieving Net Zero.

But the heat pump market in Britain is small and consumers – particularly those living on the gas grid – have been slow to switch to the technology. Research suggests this is partly driven by economics but also due to challenges in current domestic consumer proposition, such as the varying thermal efficiency of the UK’s housing stock and extremely high market penetration of gas boilers.

To date, most heat pumps in Britain have been installed in large, off-gas grid homes, where there are fewer barriers to deployment. They are also being predominantly installed by either well off early adopters, housing developers or social landlords.

The government has set an ambition to support the electrification of heat and the growth of the domestic heat pump market from around 40,000 installations in 2023 to 600,000 per year by 2028.

Project aims

The Electrification of Heat Demonstration Project sought to understand the technical and consumer barriers and provide evidence on the feasibility of a large-scale rollout of heat pumps, by seeking to increase confidence in the technology to levels that could underpin a public debate and strategic decisions on the future of heat networks.

The project aimed to:

• Develop, test and evaluate products and services that increase the appeal of heat pumps and identify optimal solutions for a wide range of homes.
• Demonstrate that heat pumps, including gas-electric hybrids, can deliver high consumer satisfaction across a wide range of consumers in Great Britain.
• Demonstrate the practical and technical feasibility of heat pumps, including gas-electric hybrids, across Great Britain’s diverse housing stock, as well as identifying the costs.
• Capture learning from the project to help improve awareness across the renewable heating supply chain, raise acceptance and support wider deployment of heat pumps in Great Britain.

What we did

We managed the project which saw a total of 742 heat pumps installed by the delivery contractors – Warmworks (Scotland), E.ON (north-east of England), and OVO Energy (south-east of England – excluding London) – into a broad spectrum of housing types (41% detached, 43% semi-detached, 11% mid-terrace, and 6% flats) and ages (68% pre-1980).

Heat pumps were installed in homes with varying Energy Performance Certificate (EPC) ratings from A down to G. At least 53% of homes involved in the demonstration project had an energy efficiency rating of C or D before the heat pump installation.

Four different heat pump types were installed, Low Temperature Air Source (LT ASHP) 41%, High Temperature Air Source (HT ASHP) 33%, Ground Source (GSHP) 5%, and Hybrid 20%.

The full consumer pathway was evaluated, and all heat pumps were monitored to form the project insights which will be used to help unblock the barriers to heat decarbonisation across the country.

Project findings and impact

The Demonstration Project has provided evidence to demonstrate that the large-scale roll out of heat pumps is feasible in the UK and has evidenced that heat pumps can be installed in a wide variety of housing archetypes. Additionally, the Project found a high degree of customer satisfaction with the installation journey and the end-product.

We’re committed to ensuring that industry and stakeholders get the most out of the project findings. As such, we’ve made the Electrification of Heat Demonstration Project datasets available to access.

You can access the following datasets:

• Heat Pump Performance Data Summary
• Heat Pump Performance Data (Raw)
• Heat Pump Performance Data: 2-minute interval cleansed data
• Heat Pump Performance Data: 30-minute interval cleansed data
• Heat Pump Performance Data: Daily interval cleansed data
• Installation statistics 

Below, you can download the full collection of summary reports from the project, including the Summary Report, Insights from Heat Pump Performance Data Report, Heat Pump Performance Data Analysis Report, and the Optimisation Report.

Throughout the duration of the Demonstration Project, the Catapult has published findings, reports, case studies, and guides. You can access these materials below.

Many of the homes retrofitted with heat pumps in the Demonstration Project have become part of the Catapult’s network of over 5,000 Living Lab homes meaning that they can continue to support the home energy research and innovation needed to help achieve Net Zero policy ambitions.