Collector

Collector. A device to trap solar radiation and extract the usable heat. A collector can refer to an insulated frame with a panel made from a material that absorbs the thermal energy and a clear cover [usually glass] generally containing inlets and outlets for the collection medium to move through it.

A solar hot air collector can be as simple as windows facing the sun or a complex configuration of absorber plates, galleries, fans and high tech glazing.

A solar hot water collector can be as simple as a garden hose laid in the sun or a very complex affair of pumps and tuubes under glazing.

Growing things are collectors, also, strictly speaking. They convert solar energy, nutrients from the soil and water into biomass. With plants the energy is contained in the plant in chemical forms that can be converted to energy by many methods including ingestion and conversion to energy to fuel animal life. Burning firewood converts the chemical energy stored by photosynthesis acting on water and soil nutrients from the chemical form to heat. A methane digester, a fermenter combined with an alcohol still, and gasifiers can also extract the heat energy from biomass.