Question to the Department for Energy Security & Net Zero:

To ask the Secretary of State for Energy Security and Net Zero, what assessment his Department has made of the potential impact of zero emission domestic boilers on the transition to net zero.

Zero emission boilers, or heat batteries are a promising technology because they utilise time-of-use tariffs, do not require outside space, and can be cheaper to install than heat pumps in some circumstances. However, they are also less efficient than heat pumps and will therefore use more energy to meet the same heating demand.

The Department is exploring, through studies like the Homes for Net Zero Trial, the role heat batteries could play in the future. We will continue to review our position on heat batteries, and other alternative electric heating technologies, as the supporting evidence base develops.