Abstract: A solar power plant includes central receiver modules arranged in a regular pattern. Each central receiver module includes a tower, a central receiver mounted on the tower, and a heliostat array bounded by a polygon. The heliostat array includes heliostats with mirrors for reflecting sunlight to the central receiver. The heliostats are grouped in linear rows and each of the rows is parallel to another row. The locations of the heliostats are staggered between adjacent rows. The power plant also includes a power block for aggregating power from the central receivers and power conduits for transferring power from the central receivers to the power block.

Abstract: Methods, systems, and devices for a triangular heliostat structure comprising a heliostat drive mounted on a post at each corner of the structure. Embodiments include determining an installation position of a heliostat structure based on the position of an adjacent heliostat structure when a pivotable spacing bar is detachably attached to at least two posts of the heliostat structures and may be based on the heliostat structures comprising three posts in a triangular configuration.

Abstract: A drive assembly for a heliostat is described, wherein the drive assembly may be configured to dynamically adjust the position of an attached reflector in concentrated solar power applications. The drive assembly may be further configured to provide for biasing of the reflector to reduce backlash due to external loads. The biasing force may be provided by at least one of a spring, counterweight, or offset of the center of gravity of the reflector or other attachment, or some combination thereof.

Abstract: Methods and systems for optimizing the startup, shutdown, and running operation of a multiple receiver concentrated solar power (CSP) plant comprising a predicted variable from at least one receiver model, a predicted variable from a plant model, and a determined target from an optimizer based on the predicted variable from the at least one receiver model and the predicted variable from the plant model.

Abstract: A heliostat array having a variable field density for use in a concentrating solar power (CSP) plant. Heliostats are arranged into subgroups and configured to track the sun and reflect light to a receiver tower. Heliostats are deployed onto structures, wherein the structures can be arranged in rows separated by a service gap. The structures can comprise cross members that can be varied in size. By altering the size of cross members in a structure, heliostats in one row can be deployed farther apart or closer together than heliostats in a different row. Heliostat field density can vary with distance from the receiver tower, wherein heliostats close to the receiver are more tightly packed and heliostats further from the receiver are spaced farther apart.

Abstract: Methods and systems for setting a throttle at a solar power plant, by a controller, the controller configured to select at least one aim point on a receiver of the solar power plant, calculate a desired energy to be delivered by two or more subgroups to each selected aim point via a search method based on an aiming scheme, and determine an optimum distribution of energy to be delivered to the receiver across the two or more subgroups via a search program based on the calculated desired energy.

Abstract: Methods and systems for measuring heliostat reflectivity with a control processing unit configured to receive an image of a heliostat, receive an image of the Sun, process the received images, and determine a reflectivity estimate based on a comparison of the processed images.

Abstract: A network topology for powering and communicating with groups of heliostats in a concentrated solar power plant. Heliostats are arranged in rows and wired together with inter-drive cables that distribute power and data from a field electrical system and plant network. Data is transmitted to and from heliostat drive control boards via network switches connected to intelligent power distribution units. Power is transmitted from battery banks to said intelligent power distribution units. Communication interface modules supply a connection between intelligent power distribution units and the heliostat control boards of non-adjacent heliostat rows to create communication and data loops having improved redundancy and robustness in the event of single point component failures.

Abstract: A system and method for detecting heliostat failures in a concentrating solar plant, the system comprising a plurality of stationary lights and cameras mounted to towers that surround, or are situated within, a field of heliostats. Heliostats may be commanded via a control system to move to a position wherein light may be expected to be reflected from a given stationary light to a given camera, whereupon a first set of images of the heliostat are taken. Heliostats may then be commanded via the control system to move to a position wherein light may no longer be expected to be reflected from said stationary light to said camera, whereupon a second set of images of the heliostat are taken. An image processor may search the first and second set of images to determine if reflected light is present. If reflected light from said stationary light is not found in the images, the heliostat may be determined to have experienced a failure mode. Failed heliostats may then be flagged for inspection, repair, or replacement.

Abstract: A drive assembly for a heliostat is described, wherein the drive assembly may be configured to dynamically adjust the position of an attached reflector in concentrated solar power applications. The drive assembly may be further configured to provide for biasing of the reflector to reduce backlash due to external loads. The biasing force may be provided by at least one of a spring, counterweight, or offset of the center of gravity of the reflector or other attachment, or some combination thereof.

Abstract: A system and method for detecting heliostat failures in a concentrating solar plant, the system comprising a plurality of stationary lights and cameras mounted to towers that surround, or are situated within, a field of heliostats. Heliostats may be commanded via a control system to move to a position wherein light may be expected to be reflected from a given stationary light to a given camera, whereupon a first set of images of the heliostat are taken. Heliostats may then be commanded via the control system to move to a position wherein light may no longer be expected to be reflected from said stationary light to said camera, whereupon a second set of images of the heliostat are taken. An image processor may search the first and second set of images to determine if reflected light is present. If reflected light from said stationary light is not found in the images, the heliostat may be determined to have experienced a failure mode. Failed heliostats may then be flagged for inspection, repair, or replacement.

Abstract: An automated deflectometry system and method for assessing the quality of a reflective surface for use in a concentrating solar power plant. The deflectometry system comprises a holding fixture for mounting a heliostat reflector opposite a target screen having a known pattern. Digital cameras embedded in the target screen take pictures of the known pattern as reflected in the surface of the reflector. Image processing software then detects the features of the pattern in the reflector images and calculates the slope profile of the reflective surface. The slope field can be calculated by comparing the images of the reflective surface to those of a reference surface. Based on the slope profile of the reflective surface, a ray tracing calculation can be performed to simulate flux as reflected from the reflective surface onto a receiver and a quality metric can be ascribed to the heliostat reflector. The result of the quality assessment can displayed using a graphical user interface on an automated assembly line.

Abstract: A system for regulating the temperature and flow rate of a heat transfer fluid for use in a hybrid steam-generating plant is described. A bypass section may be incorporated into the piping network of a primary steam-generating source to route heat transfer fluid from a hot source to a mixer downstream of at least one heat exchanger. Heat transfer fluid from the hot source may be mixed with cooler heat transfer fluid exiting the heat exchanger in the event that the supply from a secondary steam-generating source is lost or becomes intermittent. The result is a system that maintains a constant flow rate of heat transfer fluid through the heat exchangers while minimizing adverse temperature gradient effects that may result from steam production variability and plant operation outside of design point parameters.

Abstract: A comprising a ground mount, a reflector assembly comprising a mirror and a frame rigidly connected to the mirror, a drive assembly configured to rotate the reflector assembly with respect to the ground mount about a predetermined angular range, and a mounting mechanism configured to connect the drive assembly to the reflector assembly and comprising a shaft connected to the drive assembly, where the drive assembly is configured to rotate the shaft about a longitudinal axis of rotation, an attachment for connecting the frame to the shaft at a fixed angle about the longitudinal axis; and a clamp for connecting the shaft to the frame.

Abstract: Embodiments provide a solar-thermal receiver comprising: (a) a light-absorbing panel comprising: (i) a light-absorbing outer surface; and (ii) an inner volume configured to admit the flow of heat transfer fluid; (b) an inlet configured to receive heat transfer fluid; and (c) an outlet configured to output the heat transfer fluid from the volume under hydrostatic pressure. Embodiments may include vanes and/or other flow-directing and/or flow-impending structural elements.

Abstract: A solar power plant includes central receiver modules arranged in a regular pattern. Each central receiver module includes a tower, a central receiver mounted on the tower, and a heliostat array bounded by a polygon. The heliostat array includes heliostats with mirrors for reflecting sunlight to the central receiver. The heliostats are grouped in linear rows and each of the rows is parallel to another row. The locations of the heliostats are staggered between adjacent rows. The power plant also includes a power block for aggregating power from the central receivers and power conduits for transferring power from the central receivers to the power block.

Abstract: Embodiments provide a solar thermal receiver comprising: (a) a first containing member transparent to sunlight; (b) a second containing member comprising an inner surface reflective of sunlight; (c) an inlet proximate to the first containing member that is configured to receive injected heat transfer fluid; and (d) an outlet distal from the first containing member, where the first containing member and the second containing member together form a vessel configured to conduct injected heat transfer fluid from the inlet to the outlet under hydrostatic pressure.

Abstract: A receiver system for harnessing solar radiation. Embodiments of a receiver system include a receiver including one or more receiver elements, each receiver element including: a plurality of transparent tubes including a first tube and at least one second tube at least partially within the first tube; a first passage interposed between the first tube and the at least one second tube, the first passage having an inlet and an outlet; a second passage within the at least one second tube, the second passage having an inlet and an outlet; and an absorber in the at least one second tube, the absorber adapted to absorb the solar radiation. In some embodiments, a receiver further includes a housing having at least one transparent portion, the housing configured to enclose the plurality of receiver elements, whereby a third passage is formed between the first tube and the housing.

Abstract: Systems and methods of heliostat reflector cleaning via a vehicle in a heliostat field.

Abstract: A suntracking system for a central receiver solar power plant includes a heliostat field for reflecting sunlight to a receiver, cameras directed toward at least a subset of the heliostats, and a controller. The cameras are configured to produce images of sunlight reflected from multiple heliostats. The heliostats include a mirrored surface having a settable orientation and have a geometry modeled by a set of parameters. A method of estimating heliostat parameters for open-loop suntracking includes acquiring pointing samples by setting the direction of reflection of the heliostats and detecting concurrent sunlight reflections into the cameras. The method uses the acquired pointing samples and surveyed locations of the cameras to estimate the heliostat parameters. The method accurately maintains the sun's reflection directed toward the receiver open-loop utilizing the estimated tracking parameters.