259 results about "Solar irradiance" patented technology

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.

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.

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 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.

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.

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.

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 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.

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.