The plunging cost of solar power is leading U.S. electric companies to capture more of the sun just when President Donald Trump is moving to boost coal and other fossil fuels. Solar power represents just about 1 percent of the electricity U.S. utilities generate today, but that could grow substantially as major electric utilities move into smaller-scale solar farming, a niche developed by local cooperatives and non-profits. It’s both an opportunity and a defensive maneuver: