A concentrating solar power plant includes a solar light capturing part configured to capture solar light; and a heat exchange part configured to transform solar energy, from the captured solar light, into heat, which is stored in a solid medium, wherein the solid medium is stored underground. The solar light capturing part has a heliostat farm, a beam down solar concentrator, and a compound concentrator, each configured to reflect the solar light.

A concentrating solar power plant includes a solar light capturing part configured to capture solar light; and a heat exchange part configured to transform solar energy, from the captured solar light, into heat, which is stored in a solid medium, wherein the solid medium is stored underground. The solar light capturing part has a heliostat farm, a beam down solar concentrator, and a compound concentrator, each configured to reflect the solar light.

A heat transfer system and related method of heat transfer is provided. The heat transfer system includes a tubular receiver positioned to receive heat from a heat source, the receiver comprising one or more enclosed tubes configured for gravity-driven flow of a particulate heat transfer fluid therethrough in a dense, unfluidized state having a particle volume fraction of at least about 25%; and at least one storage vessel in fluid communication with the tubular receiver and positioned to receive the heat transfer fluid therefrom, wherein the particulate heat transfer fluid includes a plurality of particles of a metal-containing material having a melting point of greater than 800 C, the heat transfer fluid being substantially free of a liquid component.

A converter of kinetic energy from a jet formed by a heat transfer fluid and a gas at high temperature, includes: at least one injector of the jet from at least one source of heat transfer fluid and of high-temperature gas, an impulse wheel mounted rotating secured to a shaft extending along an axis substantially perpendicularly to the injector and including a plurality of asymmetric blades, a tank surrounding said impulse wheel and at least one deflector extending underneath the blades.

A linear actuator and a method of operating is provided. The linear actuator includes a housing having at least one wall made from an electrochromatic material configured to transform from an opaque to a translucent material in response to a voltage. A plunger is slidably coupled to the housing to move between a first position and a second position. An actuator is disposed between the plunger and the housing, the actuator being made from a heat sensitive material, the actuator being configured to change a length of the actuator in response to a change in temperature.