The future role of heat pumps in the domestic sector

Heat pumps for domestic heating and hot water supply are currently a niche technology in many EU countries, but they are increasingly expected to form an important role in a low carbon future. This is largely because a future of rapidly decarbonised electricity supply is imagined, in which using electricity via heat pumps is one of the lowest carbon heating options. However, heat pumps are not necessarily a low carbon option at present. In the UK, with fairly carbon-intensive electricity and where natural gas is available for heating, heat pumps do not make significant carbon savings for most householders. For heat pumps to become a credible low carbon solution in the UK, three transitions unrelated to heat pumps have to occur: (1) transition to low carbon electricity supply; (2) transition to well-insulated housing stock via retrofit; (3) transition to low temperature household heat distribution systems. The most difficult condition for the success of a transition to heat pumps might be entirely unrelated to the technology itself. The risks of heat pumps not delivering expected carbon savings, therefore, are much greater than the risks inherent in this technology. The future role of heat pumps links demand and supply side issues. The benefits of heat pumps vary between countries, regions, individual households and also over time. This makes a policy promoting heat pumps different, and more complex, than policy supporting energy efficiency, which offers universal benefits. This paper explores the technological, economic, social and energy supply factors which determine the benefits heat pumps could deliver in the UK and other EU countries. It looks at potential mechanisms for moving heat pumps from a niche product to the mainstream. It focuses on the wider issues around the parallel transitions required and debates how, and whether, energy and carbon policy can deal with the complexities involved.