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.
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.
Abstract:
A photovoltaic efficiency estimator, comprising a photovoltaic cell covered by a sunlight-penetrable surface; an illuminator for artificially illuminating said surface; and a controller connected to said photovoltaic cell and to said illuminator, said controller being configured to measure an amount of voltage produced in said photovoltaic cell as a result of the artificial illumination by said illuminator, so as to estimate a decrease in the efficiency of said photovoltaic cell caused by dirt on said surface.
Abstract:
An optical concentrator is disclosed which includes an imaging, aplanatic optical element having a front surface with a one-way light admitting portion, a back surface with a reflective portion, and an interior region of refractive material disposed between the front and backs surfaces.
Abstract:
Adherence to flux or resultant measurable parameter limits, ranges, or patterns can be achieved by directing heliostat mounted mirrors to focus on aiming points designated on the surface of a solar receiver. Different heliostats can be directed to different aiming points, and a heliostat can be directed to different aiming points at different times. The cumulative flux distribution resulting from directing a plurality of heliostats to any aiming point on a receiver surface can be predicted by using statistical methods to calculate the expected beam projection for each individual heliostat or alternatively for a group of heliostats. Control of the heliostats in a solar power system can include designating aiming points on a receiver from time to time and assigning heliostats to aiming points from time to time in accordance with an optimization goal.
Abstract:
A method for generating temporal solar irradiance values for a selected area. Binary format hillshade files are generated for selected azimuth and altitude points on the Sun's path for selected time points for the area. Data in the hillshade files is reclassified into reclassified files, on basis of the selected time points relative to the solar radiation data. The reclassified files are then summed to generate a set of normalized reclassified files, each representing a selected intermediate interval. The values for each corresponding one of the cells in the set of normalized reclassified files are summed to generate an irradiance-weighted shade file. The hillshade files are summed by inclusively OR-ing corresponding values for each of the cells in each of the hillshade files to generate respective composite files for each said selected intermediate interval. The composite files are then summed to generate a summed shade/time frequency file in which each data point therein represents the frequency of repetition of corresponding cells in the hillshade files over a selected upper interval of time. Each data point value in the irradiance-weighted shade file is then divided by the corresponding data point value in the frequency file to generate a file having solar access values for the upper interval, relative to the intermediate interval, for the selected area.
Abstract:
Method for using renewable energy sources comprising at least one remote energy generation plant which may be operated by a renewable energy source, a production measurement unit at the location of the at least one remote energy generation plant which measures the production of the at least one remote energy generation plant, a central control unit, the method comprising the following steps: a) producing a production forecast for the production of the at least one remote energy generation plant in a future time period, b) transmitting the production forecast to the central control unit via a computer network, c) operating the remote energy generation plant and measuring the production using the production measurement unit, d) comparing the measured production with the production forecast, e) notifying an operator of the at least one energy generation plant, if the measured production deviates from the production forecast beyond a predetermined level.
Abstract:
A computer which functions by a performance prediction program for a ground source heat pump system of the present invention and a performance prediction system constructed thereby include a dimensionless distance calculating means, a first dimensionless time calculating means, a second dimensionless time calculating means, a boundary time acquiring means, an underground temperature change calculating means, and a tube surface temperature change calculating means. The performance prediction program and performance prediction system can be applied to the design of heat exchange system by obtaining predicted underground temperature data for the ground source heat pump system with high accuracy and predicting the performance for the ground source heat pump system based on the resulting underground temperature changes, etc., in view of the use of a plurality of buried tubes, underground temperature change patterns for buried tubes placed at different intervals, and the use of U-shaped tube heat exchangers.
Abstract:
Method for using renewable energy sources, comprising at least one remote energy generation plant, which is operated by a renewable energy source, a remote control unit at the location of the at least one remote energy generation plant, which controls the operation thereof, and a central control unit, the method comprising the following steps: a) Producing a proposed schedule, in which for a future time period presettings for the operation of the at least one remote energy generation plant are established, and transmitting the proposed schedule to the central control unit via a computer network, b) Producing a schedule based on the proposed schedule, c) Transmitting the schedule from the central control unit to the remote control unit via a computer network, d) Automatic control of the at least one remote energy generation plant by the remote control unit according to the schedule.
Abstract:
An automated method causes a terrestrial solar cell array to track the sun. The solar cell system includes motors that adjust a position of the array along different respective axes with respect to the sun, wherein a first motor adjusts the inclination angle of the array relative to the surface of the earth and a second motor rotates the array about an axis substantially perpendicular to that surface. The method includes (a) using a software algorithm to predict a position of the sun at a future time; (b) using a computer model to determine respective positions for the motors corresponding to the solar cell array being substantially aligned with the sun at the future time; and (c) activating and operating the motors at respective particular speeds so that at the future time the solar cell array is substantially aligned with the sun. The future time may correspond to any time during operation. An initial future time may correspond to a start up time after sunrise at which point the solar cell is to begin tracking the sun.