The CGN Delingha Solar Thermal Plant (seen in an aerial view) is in the Gobi Desert in China’s Qinghai Province. It uses mirrors to concentrate sunlight onto a single receiving tower that converts the light to heat. After a meteoric rise, solar power is now the cheapest form of energy in history BY STEPHANIE PAPPAS Stephanie Pappas is a freelance science journalist based in Denver, Colo. Solar Is Now the Cheapest Way to Produce Energy in Human History FORTY-SEVEN YEARS AGO U.S. PRESIDENT JIMMY CARTER stood grinning in front of a set of 32 bulky solar panels. It was 1979, and the oil crisis had sent fuel costs skyrocketing. …