A flat-plate collector consists basically of an insulated metal box with a glazed glass cover and a dark-colored absorber plate. Heat from the sun strikes the absorber plate and is transferred to a fluid that circulates through the collector in tubes.

Flat solar collectors are very popular for their large absorption area and nice appearance. It can be mounted in a variety of ways, depending on the type of building, application, and size of collector. Options include mounting on a roof, in the roof itself, or free-standing.