Homeowners installed more than 186,000 residential systems in 2014, the third consecutive year the residential market grew by more than 50%, according to the Solar Energy Industry Association (SEIA). Falling prices for solar panels (especially those made in China) and flexible financing and leasing options have helped bring solar power systems into the mainstream. Homeowners are also keeping an eye on the renewable-energy tax credit, which expires at the end of 2016. The cost of residential solar has fallen by nearly half since 2010, to an average of $3.57 per watt of capacity, says Ken Johnson, of the SEIA. The typical home system has 6 kilowatts of capacity, so that translates to about $21,400. But the federal tax credit trims the cost to about $15,000, and state and local incentives bring the cost down even more.