Abstract: A gas receiver configured to heat a working fluid is disclosed. The receiver comprises an aperture, a light absorber, and a pre-heater interposed between the aperture and light absorber. The pre-heater is transparent to visible light and opaque to infrared. The pre-heater in the preferred embodiment comprises quartz in the form of a plurality of quartz plates or quartz tubes, for example, that are oriented substantially parallel to one another. The quartz plates are separated from one another by a gap to permit air to pass into the receiver cavity, while the quartz tubes are hollow to permit air to pass therethrough. The quartz plates or tubes are configured to transmit visible light from the aperture to the light absorber, and to absorb infrared radiation passing from the light absorber toward the aperture. Since the quartz structures absorb infrared, they serve to capture blackbody radiation emitted from the absorber and use that energy to pre-heat air before it passes into the absorber.

Abstract: A supercritical CO2 turbo-generator system includes multiple turbine generator units, a direct current bus, a plurality of active rectifiers, and a voltage controller. Each turbine generator unit includes a turbine with a supercritical CO2 input and a supercritical CO2 output, a generator with an electrical input and power output, a shaft connecting the turbine and generator, and a speed sensor for sensing shaft speed. The turbine generator units are connected in a cascading series with the input of a first turbine generator unit connected to a heated supercritical CO2 source and the input of each subsequent turbine generator unit is connected to the output of a prior turbine generator unit. The voltage controller monitors the speed sensor of the turbine generator units and varies the load on each generator to control shaft speed. Each active rectifier converts the power output of a generator to direct current, and the power from multiple active rectifiers is combined by the direct current bus.

Abstract: A system and method for reducing power consumption and increasing reliability in a solar tracking system is disclosed. The solar tracker comprises a panel, at least one actuator configured to control the orientation of the panel, and a tracking controller. The tracking controller is configured to determine a minimum operating current for the at least one actuator based on a range of motion of the panel, and energize the at least one actuator based on the minimum operating current. The tracking controller determines the minimum operating current based on the range of motion of the panel, specifically the minimum current need to drive the panel through a measured range of motion equal to or substantial similar to the full mechanical range of motion of the panel. Based on the minimum operating current, solar tracker may generate messages to repair or replace an actuator or gearbox, for example.

Abstract: A system and method for tracking the sun with a heliostat mirror is disclosed. The solar tracking system comprises: a camera configured to capture high dynamic range images of the sky, a plurality of cameras configured to capture images of the heliostat mirror, and a tracking controller. The images of the heliostat mirror include reflections of the sky. The tracking controller is configured to generate a circumsolar radiance map characterizing the brightness of at least a portion of the sky with the high dynamic range images.