Abstract: A solar concentrator has frame members connected together to form a framework, and a flexible sheet attached to the framework such that the flexible sheet takes a loose shape and can flex in response to shaping forces exerted thereon. The sheet has a reflective surface located between the frame members. A shaping force system is operative, when activated, to exert the shaping forces on the sheet, the shaping forces configured to draw the sheet from the loose shape into a desired shape such that solar rays striking the reflective surface are focused on a target, and a solar energy receiver is attached to the framework at a location corresponding to the target. Thin wall tubing filled with pressurized air can provide strong light frame members. When the shaping force system is deactivated, the flexible sheet reverts substantially to the loose shape.

Abstract: A thermal energy storage system has an insulated storage container filled with a particulate earth material. A heat input conduit circuit is buried in the earth material and transfers heat from an input liquid flowing in the heat input conduit circuit to the earth material. A heat output system is operative to transfer heat from the earth material in the storage container to an external heat consumer. During operation the input liquid enters the inlet port of the heat input conduit circuit at an input operating temperature and leaves the outlet port at an output operating temperature, and the output operating temperature is above about 650° C. The input liquid remains liquid at the input and output operating temperatures under atmospheric pressure. Energy is stored at a relatively high temperature compared to the prior art, and provides increased efficiency for heat consuming processes.

Abstract: A solar concentrator has frame members connected together to form a framework, and a flexible sheet attached to the framework such that the flexible sheet takes a loose shape and can flex in response to shaping forces exerted thereon. The sheet has a reflective surface located between the frame members. A shaping force system is operative, when activated, to exert the shaping forces on the sheet, the shaping forces configured to draw the sheet from the loose shape into a desired shape such that solar rays striking the reflective surface are focused on a target, and a solar energy receiver is attached to the framework at a location corresponding to the target. Thin wall tubing filled with pressurized air can provide strong light frame members. When the shaping force system is deactivated, the flexible sheet reverts substantially to the loose shape.