Geographic Location

Every location has an average amount of daily full sun exposure. This is known as the insolation factor. Full sun supplies 1000 watts of radiation per sq meter. A location with 5 hours of full sun exposure per day would have 5000 s

Most places have a very good solar resource. Germany, for example, is one of the leading solar markets in the world, and it has about the same insulation as the worst locations in the United States. If your location has a low insulation factor, a slightly larger collector area will provide the necessary additional energy demand.