By 2017, solar power capacity in the U.S. will have nearly tripled in less than three years, according to the U.S. Department of Energy. Combined wind, utility-scale and distributed solar power accounted for more than 66% of all new capacity installed in the U.S. last year. Already, more than twice the number of Americans — about 209,000 — work in the solar industry compared with coal and by 2020, that number will double to more than…