Research led by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) calculates the value solar photovoltaic (PV) systems can add to single-family homes, and includes recommendations for improving PV home valuation. It is part of the DOE's SunShot initiative to make solar energy cost-competitive with traditional energy sources, and reduce the cost of solar electricity to $0.06 per kilowatt-hour before the end of the decade.
Using an industry-standard paired-sales valuation technique, seven appraisers from six states estimated that homebuyers would pay up to $15,000 for houses with average-sized solar arrays compared to similar homes without PV arrays. Sun Number, a DOE SunShot-funded startup, and Redfin provide further research, ranking the premiums for solar and non-solar listings in some Midwest cities.
Sun Number uses a patented automated process to analyze the solar potential of rooftops based on pitch, orientation, and size of the roof; the amount of solar radiation per square meter; and local factors. The average Sun Number for roofs in each city is listed in the slideshow on a scale from 1 to 100, with 100 being the highest potential for energy generation.