Method for determining temporal solar irradiance values
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.
1. A method for generating temporal solar irradiance values comprising:
generating binary format hillshade files, for selected azimuth and altitude points on the Sun's path for selected times, wherein each of the hillshade files comprises a matrix of data cells representing shaded relief patterns for a selected area;
reclassifying data in the hillshade files into reclassified files, on basis of the selected time points relative to the solar radiation data, wherein each of the hillshade files includes data for one of a selected number of different time points for a selected number of intermediate time intervals in a selected upper time interval;
summing the reclassified files to generate a set of normalized reclassified files;
summing the values for each corresponding one of the cells in the set of normalized reclassified files to generate an irradiance-weighted shade file;
summing the hillshade files, by inclusively OR-ing corresponding values for each of the cells in each of the hillshade files to generate respective composite files for each of the selected intermediate time intervals;
summing the composite files 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 the selected upper time interval; and
dividing each data point value in the irradiance-weighted shade file by the corresponding data point value in the frequency file to generate a file comprising solar access values for the upper time interval, relative to the intermediate time interval, for the selected area.
2. The method of claim 1 , wherein each of the cells in each of the hillshade files contains a binary number representing either a shadow or a non-shadow condition of a specific X/Y coordinate within the selected area for a specific time.
3. The method of claim 1 , wherein each of the hillshade files includes data for the same time points for different ones of the intermediate intervals in the upper interval.
4. A method for generating temporal solar irradiance values comprising:
generating binary format hillshade files, for selected azimuth and altitude points on the Sun's path for selected time points, wherein each of the hillshade files comprises a matrix of data cells representing shaded relief patterns for a selected area;
reclassifying data in the hillshade files into reclassified files, on a basis of the selected time points relative to insolation of the selected area;
summing the reclassified files to generate a set of normalized reclassified files each representing a selected intermediate interval of time;
summing the values for each corresponding one of the cells in the set of normalized reclassified files to generate an irradiance-weighted shade file;
summing the hillshade files, 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;
summing the composite files 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; and
dividing each data point value in the irradiance-weighted shade file by the corresponding data point value in the frequency file to generate a file comprising the temporal solar irradiance values for the upper interval, relative to the intermediate interval, for the selected area.
5. The method of claim 4 , wherein each of the cells in each of the hillshade files contains a binary number representing either a shadow or a non-shadow condition of a specific X/Y coordinate within the selected area for a specific time.
6. The method of claim 4 , wherein each of the hillshade files includes data for the same time points for different ones of the intermediate intervals in the upper interval.
7. The method of claim 4 , wherein each of the hillshade files includes data for one of a selected number of different time points for a selected number of intermediate intervals in a selected upper interval.
8. A method for generating temporal solar irradiance values for a selected area comprising:
generating a plurality of hillshade files, using X/Y/Z digital elevation model data, for a plurality of points representing the Sun's azimuth and altitude relative to the selected area, using values for astronomical positions of the sun relative to the latitude and longitude for each of the points, wherein each of the hillshade files comprises a matrix of cells containing binary numbers, each representing either a shadow or a non-shadow condition of a specific X/Y coordinate within the selected area for a specific time;
reclassifying each of the hillshade files, based on irradiance levels, to generate reclassified hillshade files, wherein each of the cells therein represents the percentage of total solar radiation during a respective lower time interval for the selected area;
generating a set of normalized reclassified files by summing groups of the reclassified hillshade files, wherein each file in the set represents the sum of all of the associated normalized files within at least one selected intermediate interval of time;
summing the values for each corresponding one of the cells in the set of normalized reclassified files, within a selected upper interval of time represented by the set of normalized reclassified files, to generate an irradiance-weighted shade file for the upper interval;
summing each of the hillshade files, by inclusively OR-ing corresponding values for each of the cells in each of the hillshade files to generate a set of composite files for the selected intermediate intervals;
summing set of composite files to generate a single composite hillshade frequency file in which each data point therein represents the frequency of repetition, of corresponding said cells in the hillshade files for the lower interval, over the upper interval; and
dividing the irradiance-weighted shade file by the summed shade/time frequency file, using a matrix division operation, to provide a file indicating the average percent of solar access per said cell for the upper interval, relative to the intermediate interval.
9. The method of claim 8 , wherein each of the hillshade files includes data for the same time points for different ones of the intermediate intervals in the upper interval.
10. The method of claim 8 , wherein each of the hillshade files includes data for one of a selected number of different time points for a selected number of intermediate intervals in a selected upper interval.
11. A method for predicting the total output of a solar energy system over a selected interval of time comprising:
generating binary format hillshade files, for selected azimuth and altitude points on the Sun's path, for selected times within the interval, wherein each of the hillshade files comprises a matrix of data cells representing shaded relief patterns for an area covered by the solar energy system;
reclassifying data in the hillshade files into reclassified files, on basis of selected time points relative to the solar radiation data;
summing the reclassified files to generate a set of normalized reclassified files; and
calculating time-dependent irradiance values for the area covered by the solar energy system by summing the values for each corresponding one of the cells in the set of normalized reclassified files to generate an irradiance-weighted shade file indicating the total output of the solar energy system over the selected interval of time.
12. The method of claim 11 , wherein each of the cells in each of the hillshade files contains a binary number representing either a shadow or a non-shadow condition of a specific X/Y coordinate within the selected area for a specific time.
13. The method of claim 11 , wherein the output of the solar energy system is used to generate a data profile for a location of interest.
14. The method of claim 13 , wherein the area covered by the solar energy system is a user-defined polygon.
15. A method for determining a solar energy profile for a selected area over a selected interval of time comprising:
generating binary format hillshade files, for selected azimuth and altitude points on the Sun's path, for selected times within the interval, wherein each of the hillshade files comprises a matrix of data cells representing shaded relief patterns for the selected area;
reclassifying data in the hillshade files into reclassified files, on basis of selected time points relative to the solar radiation data;
summing the reclassified files to generate a set of normalized reclassified files; and
calculating time-dependent irradiance values for the area covered by the solar energy system by summing the values for each corresponding one of the cells in the set of normalized reclassified files to generate an irradiance-weighted shade file indicating the solar energy profile for the selected area over the selected interval of time.
16. The method of claim 15 , wherein the selected area is a portion of a single roof on a building structure.
17. A method for generating a solar energy profile over a selected time interval for a selected area comprising:
generating hillshade files from a digital elevation model for the selected area, for selected azimuth and altitude points on the Sun's path, for selected times within the interval, wherein each of the hillshade files comprises a matrix of data cells representing shaded relief patterns with cell-specific values;
applying cell-specific values, which represent the percentage insolation of the selected time interval for the selected area, to each of the hillshade files; and
agglomerating the values for each corresponding (x, y) cell in a set of the hillshade files to generate a value-weighted grid indicating the solar energy profile for the selected area, over the selected time interval on a cell-by-cell basis.
18. The method of claim 17 , wherein each said matrix of data cells represents shaded relief patterns as cell-specific total irradiance values.
19. The method of claim 17 , wherein the unobstructed portions are determined by subtracting obstruction shadows, determined from the hillshade files, from the selected area.
20. The method of claim 17 , wherein the selected area is a portion of a single roof on a building structure.
21. The method of claim 17 , wherein the selected area is a user-defined polygon.
22. The method of claim 17 , wherein the selected area is determined by a user of the method.