Rooftop solar installation prices drop as does payback time

The cost of rooftop solar installations continues to decline but not as quickly as it did in previous years, according to a report from the Lawrence Berkeley National Laboratory.
National median installed prices in 2015 declined year-over-year by $0.2 per watt (/W), or 5%, for residential systems, by $0.3/W,  or 7% for non-residential systems of  less than 500 kW, and by $0.3/W, or 9%, for non-residential systems of more than 500 kW.
Solar installation price declines have been partial