As if you needed any more evidence that installing PVs is a burgeoning business, an analysis from the Union for Concerned Scientists (UCS) demonstrates how power from rooftop photovoltaic (PV) systems is reaching a tipping point: Currently, home-generated solar power is cheaper than electricity from the local utility in 11 states plus the District of Columbia, if homeowners take advantage of a federal tax credit and available financing to install rooftop PVs. This parity can be reached in another 17 states within just three years. The map at right shows where.

Rooftop solar makes money for homeowners, which is why they keep opting for it, explains Mike Jacobs, a UCS senior energy analyst. Unlike most energy supply decisions, the choice of rooftop solar is within the homeowner's control, Jacobs notes. "There is so much that changes when solar becomes cost-effective. This is just getting started."

This is undoubtedly the time to sell on this trend. The reason for big growth over the next three years is that  the federal Investment Tax Credit, now worth 30% of a homeowner's investment in rooftop solar, will be reduced to just 10% in 2017. 
Read more from Mike Jacobs' blog