Abstract: Concrete materials and thermal energy storage devices employing such concrete materials are disclosed herein. The concrete material may include fibers in an amount ranging from about 1 to about 2 vol. %; an aggregate in an amount ranging from about 50 to about 80 vol. %, wherein the aggregates comprises siliceous aggregate and optionally carbonate aggregate; and a cementitious material in an amount from about 12 to about 20 vol. %, wherein the cementitious material comprises a combination of about 70 to about 85 vol. % of Portland cement and about 15 to about vol. % of silica fume, wherein all volume percentages unless otherwise indicated are based on the total volume of the concrete material.

Abstract: A thermal energy storage device may include a heat storage medium, one or more thermosyphons, a discharging plenum chamber, and a discharging plenum chamber. The one or more thermosyphons may include an evaporative section configured to charge the thermal energy storage device, a condensing section configured to discharge the thermal energy storage device, and a heat transfer section extending between the evaporative section and the condensing section and fluidically coupled to the evaporative section and the condensing section. At least a portion of the heat transfer section may be disposed in the solid heat storage medium. At least a portion of the evaporative section and the condensing section may be disposed outside the solid heat storage medium.

Abstract: A solar concentrator comprises a pair of concentric reflectors having a spindle toroid geometry for focusing the collected solar radiation into a ring-shaped focal area, as opposed to the “point” or “line” focus of prior art configurations. In a preferred embodiment, each reflector is formed of a plurality of curved petals that are disposed in a contiguous, keystone arrangement that requires no additional fixturing to hold the petals in place. Such an arrangement reduces the weight, complexity and cost of the final solar concentrator structure.

Abstract: A solar concentrator comprises a pair of concentric reflectors having a spindle toroid geometry for focusing the collected solar radiation into a ring-shaped focal area, as opposed to the “point” or “line” focus of prior art configurations. In a preferred embodiment, each reflector is formed of a plurality of curved petals that are disposed in a contiguous, keystone arrangement that requires no additional fixturing to hold the petals in place. Such an arrangement reduces the weight, complexity and cost of the final solar concentrator structure.

Abstract: A solar concentrator comprises a pair of concentric reflectors having a spindle toroid geometry for focusing the collected solar radiation into a ring-shaped focal area, as opposed to the “point” or “line” focus of prior art configurations. In a preferred embodiment, each reflector is formed of a plurality of curved petals that are disposed in a contiguous, keystone arrangement that requires no additional fixturing to hold the petals in place. Such an arrangement reduces the weight, complexity and cost of the final solar concentrator structure.

Abstract: Provided are apparatus and methods for storing thermal energy. For example, an apparatus including comprising at least one phase change material, and a capsule containing the at least one phase change material. The capsule may be permanently or temporarily sealed to contain the encapsulation material. The encapsulation material includes at least one material that is chemically and physically distinct from the phase change material. The encapsulation material and phase change material are selected to store and discharge thermal energy at temperatures of greater than 400° C. without capsule failure.

Abstract: A solar concentrator comprises a pair of concentric reflectors having a spindle toroid geometry for focusing the collected solar radiation into a ring-shaped focal area, as opposed to the “point” or “line” focus of prior art configurations. In a preferred embodiment, each reflector is formed of a plurality of curved petals that are disposed in a contiguous, keystone arrangement that requires no additional fixturing to hold the petals in place. Such an arrangement reduces the weight, complexity and cost of the final solar concentrator structure.