Abstract: A solar energy receiver comprises a panel, having a graphite core, a substantially gas tight housing encasing the graphite core, a heat exchanger comprising heat exchanger tubing, a heat exchanger inlet and a heat exchanger outlet. The heat exchanger tubing is at least partially embedded in the graphite core, and the heat exchanger inlet and the heat exchanger outlet extend through the housing. The housing is sealed around the heat exchanger inlet and the heat exchanger outlet. A method of manufacturing a solar energy receiver comprises: a) fabricating the heat exchanger in a serpentine coil shape; b) inserting grooved planks of graphite between individual coils of the heat exchanger to form the graphite core such that the coils are encompassed in the grooves; c) inserting the graphite and heat exchanger into the housing; and d) sealing the housing and sealing openings around the inlet and outlet where they pass through the housing.

Abstract: This invention concerns the release of stored heat energy to do useful work. In particular it concerns a method for the release of stored heat energy to do useful work, and in further aspects it concerns other methods, apparatus and systems. In a first aspect, the invention is a method for releasing stored heat energy to do useful work. The method comprising: Storing heat energy in a heat storage medium. Arranging a surface of the heat storage medium and a surface of a heat collecting element of a heat consuming engine or process, such that a surface of the heat collecting element is in proximity to, in contact with or embedded in a surface of the heat storage medium. Then, transferring stored heat energy from the surface of the heat storage medium to the surface of the heat collecting element.