(Non-combustible renewable energy source) Heat pumps that are driven by electricity or other supplementary energy, to extract (stored) energy from the air, the ground or the water and converts/transfers this into energy to be used elsewhere (e.g. To heat space via underfloor heating systems and/or water in domestic buildings). Heat pumps can be used by individual households as well as at larger scale in industry and in commercial and public services. Energy flows related to heat pumps used for cooling are excluded, only heat pumps used for heating (hot water) are included.