A solar thermal collector is a solar collector designed to collect heat by absorbing sunlight. A collector is a device for converting the energy in sunlight, or solar radiation, into a more usable or storable form. This energy is in the form ofelectromagnetic radiation from the infrared (long) to the ultraviolet (short) wavelengths. The quantity of solar energy striking the Earth’s surface averages about 1,000 watts per square meter under clear skies, depending upon weather conditions, location, and orientation of the surface.

The term solar collector refers to solar hot water panels, but may also refer to more complex installations such as solar parabolic apparatus, solar troughs, and solar towers; or less complex installations such as solar air heat. Solar power plants usually use the more complex collectors to generate electricity by heating water to produce steam which drives aturbine connected to an electrical generator. The less complex collectors are typically used in residential and commercial buildings for supplemental space heating. perpendicular to the sun’s rays.