Using historical irradiation data, we can project the generation capacity of your proposed solar installation. By experience we know this projection is very reliable. To convert that generation data to a financial return is more complicated – this requires a comparison to your consumption data. The software we have to perform that conversion is complex and requires reliable 30-minute interval data over a full year’s operation. The results of the analysis are made available early in the project along with consumption versus generation data. The financial returns may be lower or greater depending upon any changes in electrical consumption patterns – but overall this method of estimation is reasonably reliable and fully transparent.