With more than a third of days marred by fog all year round, Chongqing city in southwestern China is not the ideal place for a solar power plant. But soon it will have the nation’s first experimental facility to test a revolutionary technology allowing China to send, and receive, a powerful energy beam from space in about a decade, according to scientists involved in the project. Harvesting energy from the sun and beaming it to Earth using huge infrastructure in orbit has been regarded as science fiction, but according to a plan by the Chinese government, the nation will put...