Sunlight, trapped by glass sensors transmit their energy to absorbing metal - which warms a network of copper pipes which circulates a heat transfer fluid. This device in turn heats the water stored in a cumulus. A solar water heater produces hot water or heating generally distributed by a "direct solar floor.
All devices that act as solar thermal collectors are increasingly integrated into the bio-architecture projects (solar homes, greenhouses, walls, sensors, Trombe walls ...).
The solar thermal and solar water heaters is growing dramatically in France.

Tax credit and aid from local authorities are particularly incentives.