259 results about "Solar irradiance" patented technology

An array of solar powered photovoltaic modules is optimally oriented and operated to provide more electrical energy for uses such as powering an electrolyzer system for hydrogen production. The array is positioned with its light receiving surface at an optimal angle, preferably a continually changing angle determined by two-axis solar tracking, when continually measured solar irradiance indicates suitable sunlight, and at a horizontal position when measured solar irradiance indicates excessive atmospheric cloudiness.

Solar irradiance, the energy from the Sun's electromagnetic radiation, has a wide range of applications from meteorology to agronomy to solar power. Solar irradiance is primarily determined by a location's spatial relationship with the Sun and the atmospheric conditions that impact the transmission of the radiation. The spatial relationship between the Sun and a location on Earth is determined by established astronomical formulas. The impact of atmospheric conditions may be estimated via proxy using pixels from satellite imagery. While satellite-based irradiance estimation has proven effective, availability of the input data can be limited and the resolution is often incapable of capturing local weather phenomena. Brief qualitative descriptions of general atmospheric conditions are widely available from internet weather services at higher granularity than satellite imagery. This methodology provides logic for quantifying the impact of qualitative weather observations upon solar irradiance, and the integration of this methodology into solar irradiance estimation models.

The present invention relates to methods and systems for identifying PV system and solar irradiance sensor orientation and tilt based on energy production, energy received, simulated energy production, estimated energy received, production skew, and energy received skew. The present invention relates to systems and methods for detecting orientation and tilt of a PV system based on energy production and simulated energy production; for detecting the orientation and tilt of a solar irradiance sensor based on solar irradiance observation and simulated solar irradiance observation; for detecting orientation of a PV system based on energy production and energy production skew; and for detecting orientation of a solar irradiance sensor based on solar irradiance observation and solar irradiance observation skew.

A prediction system for predicting solar irradiance based on cloud characteristics includes a sky imager that includes a customized lens configured to capture one or more substantially planar images of the sky. The prediction system further includes an image processor coupled to the sky imager and configured to process the one or more substantially planar images. Moreover, the prediction system includes a computing system coupled to the image processor and configured to detect cloud characteristics based on the one or more substantially planar images, and predict the solar irradiance based on the cloud characteristics.

The invention discloses a photovoltaic power station output predicting method based on the optimal similar day set. The photovoltaic power station output predicting method includes steps of 1) subjecting historical data to exception handling; 2) normalizing weather types and solar irradiance as characteristic vectors of similar output level days and clustering the same for analysis through cluster algorithm and determining the final similar output level day set; 3) selecting photovoltaic generation output power as characteristic vectors of similar curve-shape days, normalizing the photovoltaic generation output power and then clustering the same for analysis through the cluster algorithm so as to obtain classification results of different cluster numbers, and finally determining a final similar curve-shape day set; 4) acquiring the type which predicting days belong to according to the maximum principle of coefficient of association; 5) constituting the optimal similar set; 6) utilizing the optimal similar set as input and establishing an output predicting model to predict photovoltaic power of the predicting days. The photovoltaic power station output predicting method can accurately predict by selecting a history data with the highest correlation with a predicting day and is simple and feasible, and accuracy in prediction of the photovoltaic generation output power is improved.

An apparatus and method, as may be used for predicting solar irradiance variation, are provided. The apparatus may include a solar irradiance predictor processor (10) configured to process a sequence of images (e.g., sky images). The irradiance predictor processor may include a cloud classifier module (18) configured to classify respective pixels of an image of a cloud to indicate a solar irradiance-passing characteristic of at least a portion of the cloud. A cloud motion predictor (22) may be configured to predict motion of the cloud over a time horizon. An event predictor (24) may be configured to predict over the time horizon occurrence of a solar obscuration event. The prediction of the solar obscuration event may be based on the predicted motion of the cloud. The event predictor may include an irradiance variation prediction for the obscuration event based on the solar irradiance-passing characteristic of the cloud.

A method and apparatus is disclosed for monitoring the performance of a solar powered electrical supply where the supply comprises an array of photovoltaic cells that are mounted on a building. In one embodiment, the apparatus comprises: a device for producing a signal representative of solar irradiance; circuitry for computing a running performance signal by using at least the irradiance signal and a measure of the electrical power supplied to the load from the array; a radio for broadcasting the performance signal; and a portable unit for receiving the performance signal from the radio and for visually displaying the performance signal, power production, and electrical utility usage.

A solar tracking system for active tracking of a solar panel array relative to the sun's position includes at least two photovoltaic (PV) sensors disposed along a common axis at opposite cardinal headings. A shadow structure is configured with the PV sensors, wherein the PV sensors are oriented relative to the shadow structure such that one of the sensors lies at least partially in a shadow cast by the shadow structure at tilt angles of the sensor on either side of a null position of the PV sensors, with the null position defined when the PV sensors are exposed to equal solar irradiance.

A prediction system for predicting solar irradiance based on cloud characteristics is presented. The system includes a sky imager that includes a customized lens configured to capture one or more substantially planar images of the sky. The prediction system further includes an image processor coupled to the sky imager and configured to process the one or more substantially planar images. Moreover, the prediction system includes a computing system coupled to the image processor and configured to detect cloud characteristics based on the one or more substantially planar images, and predict the solar irradiance based on the cloud characteristics. Methods and non-transitory computer readable medium configured to perform the method for predicting power output of one or more solar panels in a solar plant based on cloud characteristics are also presented.

The invention discloses a dynamic economic dispatching method for a power system considering photovoltaic power generation. The method comprises the following steps: historical meteorological data are acquired for statistical analysis, and solar irradiance and temperature prediction curves in the next 24 hours are obtained; statistics on historical load data is carried out, and a power system load curve in the next 24 hours is predicted and obtained; a photovoltaic power station output model is built, and a photovoltaic output prediction curve in the next 24 hours is obtained; according to a photovoltaic output probability distribution model, the photovoltaic output probability distribution in the next 24 hours and photovoltaic output values in different scenes are obtained; a dynamic economic dispatching optimization model for the power system with the photovoltaic power station is built, and a risk reserve curve is obtained; the risk reserve capacity is calculated, and a risk capacity curve is obtained; a basic UC optimization problem is solved, and a unit commitment scheme is corrected; and a dispatching scheme with the minimum target function found out during an operating cost expected value process is solved as the optimal economic dispatching scheme. The operation risk controllability and the operation economy of the power system are ensured.

The invention provides a photovoltaic power generation system performance evaluation method and device which are applied to the technical field of electronics. The method includes the steps of obtaining running data and meteorological data of a photovoltaic power generation system; calculating the function relation between theoretical output power of the photovoltaic power generation system and solar irradiance under a set reference temperature condition; obtaining the corresponding relation among actual output power of the photovoltaic power generation system, the temperature of a photovoltaic assembly and the solar irradiance; converting the actual output power to the power under the set reference temperature condition, and obtaining reference actual output power; determining the corresponding relation between the reference actual output power and the solar irradiance; drawing a curve of the theoretical output power; drawing a scatter diagram of the reference actual output power; evaluating performance of the photovoltaic power generation system. By means of the method and the device, a maintenance plan is made as required, the running and maintenance level of the photovoltaic power generation system is optimized, and life-cycle maintenance cost of the device is reduced.

Distribution of solar power in a solar DC source—variable frequency drive (VFD)—AC motor system is controlled by using solar irradiance. In addition, motor speed may be controlled as a function of available power, i.e. maximum power point tracking of motor speed, using solar irradiance.

The field of the invention relates to minimization of resistive loss of solar panels in order to achieve maximum solar energy conversion efficiency, extracting more electricity power from available solar irradiance. Schemes are designed to take advantage of the geometrical and mechanical configurations of back contact solar cells to make better electrical contacts and connections so as to achieve maximum solar energy conversion efficiency and better power extraction.

The invention discloses a method for on-orbit absolute radiation calibration, which comprises the steps of: conducting root calculation on optical thickness of an aerosol; determining parameters of an MODTRAN model according to atmospheric spectral transmittance of a measured wave band; adopting the MODTRAN model with determined parameters, and calculating to obtain atmospheric spectral transmittance on a ground target-satellite path; calculating total solar irradiance on the surface of a target; and calculating entrance pupil radiance of a satellite; looking up DN values of gray scale targets on a satellite digital image, and determining absolute calibration parameters of load carried by the satellite by combining the DN values with the entrance pupil radiance corresponding to the ground target. The invention further discloses a device for on-orbit absolute radiation calibration. By adopting the method and the device for on-orbit absolute radiation calibration, the atmospheric parameter processing procedure for on-orbit absolute radiation calibration of a remote sensing satellite is simplified, and an atmospheric transmission model most accordant with the actually-measured atmospheric condition can be determined, thereby improving the on-orbit absolute radiation calibration precision of the remote sensing satellite.

The invention relates to the technical field of distributed photovoltaic power generation systems, and particularly relates to a distributed photovoltaic ultra-short-term forecasting method based on Adaboost clustering and Markov chains. The method comprises the following steps: 1, extracting deterministic components of illumination intensity sequences by using a sliding average method, and implementing statistical analysis to obtain illumination intensity attenuation factors of different weather types; 2, implementing clustering analysis on historical data by using an Adaboost improved KNN method to establish a classification model; 3, forecasting the solar irradiance of the earth surface by using a multistage weighted Markov chain method; and 4, establishing a photoelectric conversion model to complete the ultra-short-term forecasting of photovoltaic power. According to a combination forecasting method for implementing feature extraction and data mining on input data, provided by the invention, after the historical photovoltaic output data is classified according to the typical weather type, the state of the forecasting process is refined by introducing the weather type attenuation factors, so that better forecasting effects can be achieved in sunny weather, and the forecasting precision and accuracy in non-sunny weather can also be increased.

The method of forecasting for solar-based power systems (10) recognizes that no single solar irradiance forecasting model provides the best forecasting prediction for every current weather trend at every time of the year. Instead, the method trains a classifier to select the best solar irradiance forecasting model for prevailing conditions through a machine learning approach. The resulting solar irradiance forecast predictions are then used to allocate the solar-based power systems (10) resources and modify demand when necessary in order to maintain a substantially constant voltage supply in the system (10).

A measurement system and method of forecasting time-dependent corrections into a power output of photovoltaic power generators based on a determination of time-dependent shading of photovoltaic cells. Identification of cloud positioning in the sky is based on recordation of images of a scene within a field-of-view FOV that optionally subtends the Sun, base on which images a velocity vector associated with cloud movement is computed to form output associated with time when clouds will shade power generators in question. A method for producing a weather forecast based on such corrections.

A pyranometer for measuring solar irradiance at a selected site comprises a light detector adapted to produce an output signal in response to incident solar radiation, a reversible motor having a curved shadowband attached to its output shaft, means for mounting the light detector and motor so that the shadowband is at a fixed distance from the light detector; and a motor controller that is adapted to periodically cause the motor to rotate the shadowband from one to the other of two limit positions, with the shadowband acting to momentarily shadow the light detector during its movement between its two limit positions. A datalogger stores and processes the light detector's signal output to provide a measure of total horizontal, direct normal and horizontal diffuse solar irradiance.

Estimating energy generated by a solar system in a predetermined geographic area comprises, at each predetermined time instant: retrieving measured values of at least one weather parameter and of solar irradiance in the geographic area, the values related to a time slot before the predetermined time instant; performing auto-regression analysis of the measured values; estimating, based on the auto-regression analysis, a relationship between the at least one weather parameter and the solar irradiance; retrieving forecasted values of the at least one weather parameter in the geographic area, the forecasted values being forecasted for a second time slot after the predetermined time instant; performing regression analysis of the relationship between the at least one weather parameter and the solar irradiance of the forecasted values; forecasting solar irradiance in the second time slot based on the regression analysis, and estimating energy generated by the solar system in the second time slot.

The invention discloses a photovoltaic power interval prediction method combining a deep cycle neural network and parameter estimation, belonging to the technical field of photovoltaic power prediction. The method of photovoltaic power forecasting based on a long-term and short-term memory network firstly chooses the data of product day, ambient temperature, ambient humidity, wind speed and solarirradiance as the original data of photovoltaic power forecasting. The data of product day, ambient temperature, ambient humidity, wind speed and solar irradiance are selected as the original data ofphotovoltaic power forecasting. The confidence intervals of PV power values and predicted values corresponding to 24 hourly hours of the predicted day are outputted from the predicted model to 24 hourly hours of the predicted day for 365 days of the year. This method establishes a relationship between the current photovoltaic power change and the previous photovoltaic power change, realizes the dynamic modeling of the time series data, and can reflect the change law of photovoltaic power more fully, and realizes more accurate photovoltaic power prediction. The method is easy to operate, is high in practicability and has a high promotion value.

Load-matched photo-voltaic power units incorporating a plurality of photo-voltaic cells for delivery of electrical power are described. A photo-voltaic system incorporates temperature and solar irradiance sensors, whose outputs are used to estimate the photo-voltaic system maximum power output voltage. Appropriate numbers of cells are suitably interconnected to assemble at least one photo-voltaic power unit intended to both satisfy the electrical requirements of a load and enable operation of the unit at an efficiency of 90% or greater of its maximum efficiency. In an embodiment, voltage-to-voltage convertors may be used to better match the photo-voltaic power unit capabilities to the load requirements. In another embodiment an alert is issued if the photo-voltaic power unit delivers a voltage which differs by a predetermined amount from an estimated maximum power voltage.

Photovoltaic structures for the conversion of solar irradiance into electrical free energy. In a particular implementation, a photovoltaic cell includes a granular semiconductor and oxide layer with nanometer-size absorber semiconductor grains surrounded by a matrix of oxide. The semiconductor and oxide layer may be disposed between electron and hole conducting layers. In some implementations, multiple semiconductor and oxide layers can be deposited.

The present invention relates to a measurement method to determine the magnitude and intensity of solar radiation / collected by a photovoltaic solar panel, without the need of using specific sensors for this purpose—With the present method̂ the power conditioning systems used in small photovoltaic panels to charge small rechargeable batteries, will now be able to provide an electrical signal, in the form of a pulse sequence or in any other electrical signal, that represents the value of the quantity that generates the available energy. The present method enables the monitoring the energy transfer between the solar panel and a rechargeable battery using a switched, voltage converter; additionally it indicates the magnitude of the solar radiation falling on the solar panel. It is based on the adaptation of a direct voltage to direct voltage boost converter circuit in. order to provide an electrical signal which is correlated to the magnitude of the solar irradiance falling on the solar panel, which in turn powers the voltage converter circuit. The invention also relates to a device for implementing this method.

The invention discloses a photovoltaic power generation system online IV curve test device and a test method. The online IV curve test device comprises a temperature acquisition system, a solar irradiance gauge, a multi-channel photovoltaic assembly IV tester, an industrial control computer, a switch, a host computer and a switching case. According to the online IV curve test device, a relay with relatively low cost and having no arc discharge is employed to switch photovoltaic assemblies, IV curves of the assemblies are respectively tested through rapid scanning, accurate volt-ampere characteristics of the photovoltaic assemblies are acquired, and the online IV curve test device satisfies online IV curve tests on all channel assembly strings through cascade networking at present. Through the method, after switching one assembly at each time, an output voltage of the residual assembly string is guaranteed to be greater than the lowest input work voltage of an inverter, and a cell input power is further guaranteed to be greater than a normal start power of the inverter. The whole test period of rapid assembly switching, rapid IV curve scanning test and rapid switching recovery is controlled to be quite short, the online IV curve test function is realized.

Apparatus and method, as may be used to acquire different components of solar irradiance in a solar-based power generation system or as may be used in a sky imager, are provided. A filter matrix (12) may be arranged to receive incident solar irradiance. The filter matrix may include an array of pixels (20) controllable to selectively acquire different components of the solar irradiance. A module, such as a photosensor (22) or calculator module (29) may be configured to determine a spatial location of at least one of the irradiance components relative to the array of pixels of the filter matrix. A controller (26) may be electrically coupled to the module to supply a control signal to the filter matrix based on the determined location of the irradiance component to pass a selected one of the irradiance components.

The invention provides a super-short-term power prediction method based on a clearance model for a photovoltaic power station. The method comprises the following steps: data preprocessing; model training; and super-short-term power prediction for a photovoltaic power station according to the model. According to the super-short-term power prediction method based on the clearance model, the clearance model of the photovoltaic power station by combination of the clearance model of solar irradiance with output characteristics of the photovoltaic power station, the theoretical maximum output of the photovoltaic power station at specific time can be calculated, and the super-short-term power prediction model is established by employing normalization data and combining with autoregression time sequences on the basis of the theoretical maximum output, accordingly, the prediction accuracy is effectively improved.

A system for determining a viable area automatically and accurately includes an interface and a processor. The interface is configured to receive location information. The processor is configured to determine multi-view imagery data based on the location information, to determine a point cloud using the multi-view imagery data, determine one or more features using the point cloud, determine viable area using the one or more features, and determine a solar irradiance of the viable area.

The invention relates to a method for ultra-short-term prediction of solar irradiance in clear and cloudy weather, which is based on an all-sky imager (TSI-880) ground cloud picture, including cloud retrieval of real-time ground-based cloud images, using the cloud image retrieved from the time-series cloud cover to predict the cloud image; Then, the multiple linear regression equation is constructed by using the cloud amount and clear sky factor data of n time cloud pictures before t time. Finally, the cloud amount data of t + Delta t time cloud pictures in the future are substituted into theregression model to obtain the forecast clear sky factor, and then the forecast surface irradiance of the corresponding future time is calculated. The invention can effectively predict the variation of the ground solar irradiance caused by the movement and change of the clouds in the clear and cloudy weather condition in real time, overcomes the shortcomings of the existing solar radiation prediction method such as randomness, uncertainty, large error and the like in the clear and cloudy weather condition, and realizes the advantages of good real-time performance and high accuracy.

The invention provides a flow control method for a solar heat collector system. The flow control method comprises the following steps: setting interval of a time period; determining the initial solar irradiance E of each time period; determining the initial temperature T1 of an outlet of a heat-conducting oil pipe of the heat collector system in each time period; determining the initial temperature T2 of the outlet of the heat collector system in each time period; setting the terminal temperature T3 of an outlet of the heat collector system; calculating the flow q of heat-conducting oil in the heat-conducting oil pipe; and according to the flow of heat-conducting oil, regulating the frequency Q of a heat-conducting oil pump. The flow control method for the solar heat collector system can maintain the frequency of the heat-conducting oil pump unchanged within a certain time period, thus improving the stability of the solar heat collector system.