Space-Based Solar Power

Space-based solar power is the concept of collecting sunlight in orbit with solar power satellites and transmitting the energy to Earth, most commonly proposed as a microwave beam sent to a ground receiving antenna. American engineer Peter Glaser first described the concept in November 1968 and was granted a United States patent for the transmission method in 1973; early microwave power transmission was demonstrated on the ground by William C. Brown, whose team beamed 30 kilowatts over one mile at just under 10 percent efficiency between 1969 and 1975. The concept has since been tested in space at small scale: the U.S. Naval Research Laboratory ran its first satellite-based solar power generation test in May 2020, and Caltech own MAPLE experiment demonstrated wireless power beaming in orbit and detected power received on Earth in March 2023. As of the early 2020s, Japan, China, Russia, India, the United Kingdom, the United States and the European Space Agency are all pursuing active space-based solar power programs, with China stating a goal of launching a 200 tonne operational station by 2035; no country has yet built an operational power-generating station of this kind.