There are various ways to use renewable energy to heat a building and provide hot water. Here are a few examples:

• Solar thermal energy: This is usually installed on the roof of a building and converts sunlight into heat. The system can cover part of the heat needed for hot water, e.g. for the shower, and possibly also some of the space heating.
• Biomass: Examples include wood pellet or log boilers generating heat for heating and hot water.

• Heat pump: A heat pump uses heat from the air, groundwater or the ground.