The number of solar jobs in the U.S. has more than doubled in five years. In fact, there are more people working in solar now than at oil rigs and in gas fields. The solar industry added 35,000 jobs in 2015, up 20% from the previous year, according to the Solar Foundation, a nonprofit in Washington D.C.. The group is not funded by solar companies. In contrast, oil and gas firms slashed nearly 17,000 extraction…