A heliostat optical panel assembly has a curved optical panel, a curved backing panel spaced from the curved optical panel and multiple spacers interposed between and attached to the curved optical panel and the curved backing panel. The spacers are distributed between the curved optical panel and the curved backing panel in a modular pattern to provide shear stiffness to the optical panel assembly.
A system and method for registering images captured by a camera of heliostats in a heliostat field for use in tracking control of the heliostats is disclosed. The method includes calculating a geographical location of a reflection of the sun on a reflective dome surface of fiducial markers positioned relative to the heliostat field that are in a field of view of the camera, the geographical location calculated based on a location of the sun at a time corresponding to a time-stamp of the captured image, a geographical location and a radius of the reflective dome of the fiducial markers, and a geographical location of the viewing camera. A correct mapping of the fiducial markers in the captured image is identified. Optionally, an affine transform is applied to the captured image via rotation and translation so that pixels in the transformed image for the fiducial markers map to geographical coordinates of the fiducial markers.
A system and method for registering images captured by a camera of heliostats in a heliostat field for use in tracking control of the heliostats is disclosed. The method includes calculating a geographical location of a reflection of the sun on a reflective dome surface of fiducial markers positioned relative to the heliostat field that are in a field of view of the camera, the geographical location calculated based on a location of the sun at a time corresponding to a time-stamp of the captured image, a geographical location and a radius of the reflective dome of the fiducial markers, and a geographical location of the viewing camera. A correct mapping of the fiducial markers in the captured image is identified. Optionally, an affine transform is applied to the captured image via rotation and translation so that pixels in the transformed image for the fiducial markers map to geographical coordinates of the fiducial markers.
A lightweight and rigid stand for supporting a heliostat includes multiple legs that extend between a lower end and upper end. A bracket or knuckle couples to an upper end of the legs and can support a heliostat thereon so that the bracket or knuckle is disposed between the upper end of the legs and the heliostat. A dimensional spacing or angular orientation between the legs is maintained by the backet or knuckle and/or bridge portions that extend between linear portions of the legs. Lower ends of the legs can be embedded in a ballast mass.
A lightweight and rigid stand for supporting a heliostat includes multiple legs that extend between a lower end and upper end. A bracket or knuckle couples to an upper end of the legs and can support a heliostat thereon so that the bracket or knuckle is disposed between the upper end of the legs and the heliostat. A dimensional spacing or angular orientation between the legs is maintained by the backet or knuckle and/or bridge portions that extend between linear portions of the legs. Lower ends of the legs can be embedded in a ballast mass.
F24S 25/16 - Arrangement of interconnected standing structuresStanding structures having separate supporting portions for adjacent modules
F24S 25/63 - Fixation means, e.g. fasteners, specially adapted for supporting solar heat collector modules for fixing modules or their peripheral frames to supporting elements
H02S 50/00 - Monitoring or testing of PV systems, e.g. load balancing or fault identification
F24S 30/00 - Arrangements for moving or orienting solar heat collector modules
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.
F24S 10/25 - Solar heat collectors using working fluids having two or more passages for the same working fluid layered in the direction of solar rays, e.g. having upper circulation channels connected with lower circulation channels
F24S 23/70 - Arrangements for concentrating solar rays for solar heat collectors with reflectors
F24S 80/00 - Details, accessories or component parts of solar heat collectors not provided for in groups
F24S 70/16 - Details of absorbing elements characterised by the absorbing material made of ceramicDetails of absorbing elements characterised by the absorbing material made of concreteDetails of absorbing elements characterised by the absorbing material made of natural stone
F24S 30/00 - Arrangements for moving or orienting solar heat collector modules
F24S 70/12 - Details of absorbing elements characterised by the absorbing material made of metallic material
A heliostat field layout for a concentrated solar power (CSP) plant includes a plurality of heliostats arranged adjacent each other (e.g., side-by-side) in a first arc spaced from a tower comprising a solar receiver. A second plurality of heliostats are arranged adjacent each other (e.g., side-by-side) in one or more additional arcs spaced from each other and spaced from the first arc, each additional arc spaced from a previous of the additional arcs by a radial distance that defines an aisle, the radial distance between a pair of adjacent arcs being equal to or greater than the radial distance between a previous pair of adjacent arcs in a direction away from the tower. The heliostats are arranged in the arcs in a non-staggered manner.
A heliostat field layout for a concentrated solar power (CSP) plant includes a plurality of heliostats arranged adjacent each other (e.g., side-by-side) in a first arc spaced from a tower comprising a solar receiver. A second plurality of heliostats are arranged adjacent each other (e.g., side-by-side) in one or more additional arcs spaced from each other and spaced from the first arc, each additional arc spaced from a previous of the additional arcs by a radial distance that defines an aisle, the radial distance between a pair of adj acent arcs being equal to or greater than the radial distance between a previous pair of adjacent arcs in a direction away from the tower. The heliostats are arranged in the arcs in a non-staggered manner.
G02B 26/08 - Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
G02B 7/183 - Mountings, adjusting means, or light-tight connections, for optical elements for prismsMountings, adjusting means, or light-tight connections, for optical elements for mirrors for mirrors specially adapted for very large mirrors, e.g. for astronomy
9.
TUBULAR RECEIVER FOR HEATING PARTICLES WITH SOLAR ENERGY
A particle receiver includes an inlet, an outlet and multiple tubes rotatably coupled to the inlet and the outlet. The tubes receive particles via the inlet, the particles passing along a passageway of each of the tubes to the outlet. The tubes receive a solar flux as they rotate to heat the particles passing through the tubes. A heat transfer coefficient of the particles is increased by increased mixing via air flowing in the tubes, fins used to mix the particles or via channels via which the particles pass through that increase turnover and mixing of the particles.
A particle receiver includes an inlet, an outlet and multiple tubes rotatably coupled to the inlet and the outlet. The tubes receive particles via the inlet, the particles passing along a passageway of each of the tubes to the outlet. The tubes receive a solar flux as they rotate to heat the particles passing through the tubes. A heat transfer coefficient of the particles is increased by increased mixing via air flowing in the tubes, fins used to mix the particles or via channels via which the particles pass through that increase turnover and mixing of the particles.
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.
H02P 8/16 - Reducing energy dissipated or supplied
G02B 7/182 - Mountings, adjusting means, or light-tight connections, for optical elements for prismsMountings, adjusting means, or light-tight connections, for optical elements for mirrors for mirrors
An air receiver for use in a solar power plant receives sunlight from a plurality of heliostats focused on the air receiver via an aperture of the receiver to heat air in the cavity of the receiver. The heated air is directed out of the receiver via one or more output ports in fluid communication with the cavity. A solar power tower can include one or more receivers (e.g., oriented in different directions) and have outflow conduit(s) in fluid communication with the output ports. The outflow conduit(s) receive heated air from the one or more receivers and direct it toward one or both of a hot thermal storage tank and a heat utilization module (e.g., for use in generating electricity or facilitating an industrial process, such as a chemical reaction).
An air receiver for use in a solar power plant receives sunlight from a plurality of heliostats focused on the air receiver via an aperture of the receiver to heat air in the cavity of the receiver. The heated air is directed out of the receiver via one or more output ports in fluid communication with the cavity. A solar power tower can include one or more receivers (e.g., oriented in different directions) and have outflow conduit(s) in fluid communication with the output ports. The outflow conduit(s) receive heated air from the one or more receivers and direct it toward one or both of a hot thermal storage tank and a heat utilization module (e.g., for use in generating electricity or facilitating an industrial process, such as a chemical reaction).
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. During tracking operations, the tracking controller is configured to estimate an orientation of the heliostat mirror; calculate coordinates of the portions of sky in the reflections in the heliostat mirror; estimate brightness levels of portions of sky in the reflections of the heliostat mirror based on the calculated coordinates and the radiance model; determine brightness levels of portions of sky in the reflections of the heliostat mirror based on the images from the plurality of cameras; generate an error measurement characterizing a difference between the brightness level estimated from the radiance model and the brightness level determined from the images of the heliostat mirror; search for an orientation angle of the at least one mirror that minimizes the error measurement; and re-orient the at least one mirror based on the orientation angle that minimizes the error measurement.
F24S 50/20 - Arrangements for controlling solar heat collectors for tracking
F24S 20/20 - Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
F24S 20/25 - Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants using direct solar radiation in combination with concentrated radiation
A61F 2/97 - Instruments specially adapted for placement or removal of stents or stent-grafts having an outer sleeve the outer sleeve being splittable
A61F 2/95 - Instruments specially adapted for placement or removal of stents or stent-grafts
A61F 2/01 - Filters implantable into blood vessels
A61F 2/958 - Inflatable balloons for placing stents or stent-grafts
15.
Multi-stage serial turbo-generator system for supercritical CO2 power cycles
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.
H02P 9/30 - Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field using discharge tubes or semiconductor devices using semiconductor devices
F01D 15/10 - Adaptations for driving, or combinations with, electric generators
F02C 1/02 - Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid the working fluid being an unheated pressurised gas
16.
Heliostat localization in camera field-of-view with induced motion
A system and method for localization and calibration of a heliostat is disclosed. The system comprises a controller and a camera configured to acquire images of a plurality of heliostats. The controller and camera are configured to acquire a first image of the plurality of heliostats, move one of the plurality of heliostats, acquire a second image of the plurality of heliostats, generate a difference image by subtracting the second image from the first image, identify the heliostat that was moved based on the difference image, and calibrate the position or orientation of the heliostat based on the difference image. The difference image is generated by pixel-wise subtraction of the second image from the first image. The pixel-wise subtraction exposes the heliostat and enables the calibration of the position and/or orientation of known heliostat positions.
A solar collector system comprising at least one heliostat and an inflatable cover configured to protectively conceal the at least one heliostat while it tracks the sun. The inflatable cover comprises a flexible membrane, which is transparent and colorless so that sunlight is transmitted through the cover. The cover may comprise an elastomeric material such as ethylene tetrafluoroethylene (ETFE). The solar collector system may further include a pump for inflating the inflatable cover, a pressure relief valve configured to prevent air pressure in the inflatable cover from exceeding a predetermined threshold, and a pressure sensor configured to automatically turn on the pump when the internal pressure falls below a predetermined threshold. The inflatable cover effectively removes wind loading from the heliostats, thus enabling the heliostats to use low-power, less-expensive actuators.
F24S 40/10 - Protective covers or shroudsClosure members, e.g. lids
F24S 80/50 - Transparent coveringsElements for transmitting incoming solar rays and preventing outgoing heat radiation
F24S 80/525 - Transparent coveringsElements for transmitting incoming solar rays and preventing outgoing heat radiation characterised by the material made of plastics
H02S 40/00 - Components or accessories in combination with PV modules, not provided for in groups
18.
Heliostat with tripod stand and top-mounted optical member
A heliostat includes an optical member (e.g., a mirror), a mounting frame under the optical member, a support stand and a hinge assembly. The hinge assembly allows the optical member to pivot about two orthogonal directions relative to the support stand. A drive mechanism adjusts one or both of an elevation angle and a roll angle of the optical member.
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. During tracking operations, the tracking controller is configured to estimate an orientation of the heliostat mirror; calculate coordinates of the portions of sky in the reflections in the heliostat mirror; estimate brightness levels of portions of sky in the reflections of the heliostat mirror based on the calculated coordinates and the radiance model; determine brightness levels of portions of sky in the reflections of the heliostat mirror based on the images from the plurality of cameras; generate an error measurement characterizing a difference between the brightness level estimated from the radiance model and the brightness level determined from the images of the heliostat mirror; search for an orientation angle of the at least one mirror that minimizes the error measurement; and re-orient the at least one mirror based on the orientation angle that minimizes the error measurement.
A heliostat for tracking the sun is disclosed. The heliostat comprises a frame (104) with legs (102); an optical assembly (120) configured to hang between the legs of the frame by means of a plurality of wires (130); and a plurality of actuators (520) configured to change the orientation of the optical assembly via the plurality of wires. The optical assembly may include a mirror (122) or photovoltaic panel that tracks the sun, and concrete backing (610). The optical assembly may further include a tracking controller (150) to energize the plurality of actuators, photovoltaic cell (252) configured to power the tracking controller and actuators, cleaning assembly (1710), and reservoir (770) for capturing rain water on the optical assembly. The optical assembly may further include a camera (254) for capturing images of the frame and determining the orientation of the optical assembly based on the images.
A tracking system for a solar collector is disclosed. The tracking system includes at least two polarization cameras and a tracking controller configured to: determine orientations of maximal intensity of polarized light received from the at least one heliostat mirror; generate radial lines based on the orientation of maximal intensity of polarized light from the at least one heliostat mirror; determine a position of the sun based on an intersection of the radial lines; and re-orient the at least one heliostat mirror based on the determined position of the sun. In the preferred embodiment, the sun position may be determined based on radial lines corresponding to three or more cameras mounted around the receiver aperture.
The invention is a system and method for heliostat mirror control. Here, each heliostat mirror generates a low intensity “signal beam”, directed at an angle off from the heliostat mirror's high intensity and sensor blinding “main beam” of reflected solar energy. The low intensity signal beams may be created by reflecting a small portion of the incident solar light at an angle from the main beam, by reflected artificial light, or from lasers shinning onto mirrors from known locations. The signal beams are detected by optical sensors mounted way from the main heliostat receiver focus, and can be used in a closed loop control system to efficiently ensure that individual heliostat mirrors in a heliostat array accurately track sunlight and direct the sunlight to a central receiver. Because heliostat mirrors need not be taken “off sun” for positioning, the system allows heliostat arrays to be run at high efficiency.
F24S 50/20 - Arrangements for controlling solar heat collectors for tracking
G01S 3/78 - Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using electromagnetic waves other than radio waves
G01S 3/786 - Systems for determining direction or deviation from predetermined direction using adjustment of orientation of directivity characteristics of a detector or detector system to give a desired condition of signal derived from that detector or detector system the desired condition being maintained automatically
F24S 23/77 - Arrangements for concentrating solar rays for solar heat collectors with reflectors with flat reflective plates
The invention is a system and method for heliostat mirror control. Here, each heliostat mirror generates a low intensity “signal beam”, directed at an angle off from the heliostat mirror's high intensity and sensor blinding “main beam” of reflected solar energy. The low intensity signal beams may be created by reflecting a small portion of the incident solar light at an angle from the main beam, by reflected artificial light, or from lasers shinning onto mirrors from known locations. The signal beams are detected by optical sensors mounted way from the main heliostat receiver focus, and can be used in a closed loop control system to efficiently ensure that individual heliostat mirrors in a heliostat array accurately track sunlight and direct the sunlight to a central receiver. Because heliostat mirrors need not be taken “off sun” for positioning, the system allows heliostat arrays to be run at high efficiency.
F24J 2/38 - employing tracking means (F24J 2/02, F24J 2/06 take precedence;rotary supports or mountings therefor F24J 2/54;supporting structures of photovoltaic modules for generation of electric power specially adapted for solar tracking systems H02S 20/32)
patents
