Solar water heating or SWH is the process of converting sunlight into energy that can then be used for domestic water heating. This heated water can be used for washing in the home, radiant floor heating, or to heat swimming pools.

Solar water heating systems use a large number of different technologies and these technologies can be used almost anywhere in the world. Each of these systems include two main components - storage tanks and solar collectors. Additionally, there are two main types of solar water heating systems: active systems with circulating pumps and passive systems without pumps.