Abstract: A solar heat collector comprising primarily an inflatable envelope transparent to solar radiation filled with a gas, lighter than air, and tethered to the earth's surface by a pair of fluid conduits for conducting a working fluid to and from the envelope. One conduit which conducts working fluid to the envelope terminates within the envelope in a nozzle for spraying the working fluid against the inner surface of the envelope at its upper end. The fluid then flows by means of gravity along the inner surface of the envelope collecting solar heat energy and flowing by the force of gravity down the second conduit for utilization at the earth's surface.