Abstract: A cavity-type solar energy receiver for generating high pressure steam, which includes panels of tubes defining a cavity within an outer enclosure. Concentrated solar energy provided by a heliostat enters the cavity opening in the enclosure and evaporates water within some of the tube panels. The evaporating tubes receive hot water from a steam drum by natural circulation and return a mixture of steam and hot water to the steam drum. Additional tube panels are positioned to receive reflected solar energy, which is used to preheat feed water and to superheat steam.

Abstract: In accordance with one embodiment of the present invention, a first vessel for holding a mixture of steam and water is disclosed. At least one first manifold is in fluid communication with the first vessel, the at least one first manifold is for receiving water from the first vessel. At least one second manifold is in fluid communication with the first vessel and in parallel spaced relation to the first manifold, the at least one second manifold is for returning a mixture of steam and water to the first vessel. At least one tube is in fluid communication with the at least one first manifold and the at least one second manifold, and a plurality of fins extends radially outward from an outer surface of the at least one tube.