Heat pumps are devices that use electricity to transfer heat from outside to inside a building, providing a clean and efficient way to heat homes. Heat pumps work by using a refrigerant, a material that changes state from liquid to gas and back , to absorb heat from the air, ground or water outside and transfer it to the water or air inside the building. This process can more energy than the electricity that is put into it, resulting in an energy efficiency of over 100%. They are considered a crucial technology for achieving the UK’s of reaching net zero emissions by 2040, as they can replace fossil fuel-based heating systems such as gas boilers. However, heat pumps are still uncommon in the UK, with only 1% of British homes having one installed, compared to 60% of Norwegian homes. The government aims to increase this number to 80% by 2048, and has recently a 50% increase in its boiler upgrade grants, which offer households up to £7,500 to switch to a heat pump.