Written questions by Kirkham.

Whether he has made an assessment of the potential merits of taking steps to encourage rural off-grid households to switch to hydrogenated vegetable oil in heating.

As sustainable biomass is a limited resource, the Government expects to prioritise its use in sectors like aviation, and potentially the small number of homes unsuitable for heat pumps, as these sectors have fewest options to decarbonise. The cost of renewable liquid heating fuels is currently much higher than other fuels available to off grid customers. Before taking decisions on whether to support the use of renewable liquid fuels, like hydrotreated vegetable oil, in heating, the Government would require stronger evidence on their affordability for consumers, and the availability of sustainable feedstocks.

Whether he has made an assessment of the potential merits of introducing incentives on the use of heat batteries similar to those on heat pumps.

Heat batteries are a promising electric heating technology, which can be charged off-peak to utilise cheaper electricity. However, they are less efficient than heat pumps and if a battery has insufficient storage capacity, it may need to draw electricity at peak times which can add to the burden on the electricity network. Consequently, policies like the Boiler Upgrade Scheme, are currently focused on supporting heat pumps. However, my Department is exploring, through studies like the Homes for Net Zero trial, the role heat batteries could play in the future.