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.

Abstract: A system and method for identifying the solar potential of rooftops. In one embodiment, solar-potential criteria and three-dimensional spatial data and tabular data, for a selected area including parcels on which the rooftops are located, are entered into a geographic information system. Three-dimensional aerial data of the selected area, including the rooftops in the selected area, is collected. Solar azimuth and altitude angles are calculated for regular intervals to generate shadow simulation data representing shadows cast onto the rooftops by obstructions. The shadow simulation data is intersected with the XYZ coordinates of the rooftop shapes, as determined from the aerial data, to generate rooftop shade patterns for specific intervals over a specific period of time. The tabular data and the rooftop shade patterns are then used to determine addresses and per-parcel specifications of buildings having said rooftops meeting the solar-potential criteria.