see more

PORTLAND, OR - NOVEMBER 17: Phil Tussing installs photovoltaic solar panels on a residence November 17, 2005 in Portland, Oregon. Residential solar panels for both electricity production and water heating represent a growing trend for home owners in Oregon seeking energy efficiency. (Photo by Melanie Conner/Getty Images)

PORTLAND, OR - NOVEMBER 17:  Phil Tussing installs photovoltaic solar panels on a residence November 17, 2005 in Portland, Oregon. Residential solar panels for both electricity production and water heating represent a growing trend for home owners in Oregon seeking energy efficiency.  (Photo by Melanie Conner/Getty Images)