A solar thermal collector collects heat by absorbing sunlight. The term "solar collector" commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and solar towers or non water heating devices such as solar cooker, solar air heaters.
Water heating system deployed on a flat roof. The pipes that carry the heat away can be seen embedded in the absorber, a flat plate painted black. In this example the heat is stored in the tank above the panels.
Evacuated tube collector
An array of evacuated tube collectors on a roof
An array of evacuated flat plate collectors next to compact solar concentrators
Solar water heating (SWH) is heating water by sunlight, using a solar thermal collector. A variety of configurations are available at varying cost to provide solutions in different climates and latitudes. SWHs are widely used for residential and some industrial applications.
Solar water collectors installed in Spain
An advertisement for a Solar Water Heater dating to 1902
Passive (thermosiphon) solar water heaters on a rooftop in Jerusalem
Direct systems: (A) Passive CHS system with tank above collector. (B) Active system with pump and controller driven by a photovoltaic panel.
