What is space-based solar power?

Space-based solar power (SBSP) is the concept of collecting solar energy in Earth orbit using spacecraft equipped with large photovoltaic arrays, converting that energy into microwave or laser radiation, and transmitting it wirelessly to receiving stations on the ground. The ground stations convert the electromagnetic energy back into electricity for delivery to the grid. The core idea is that a satellite in geostationary orbit receives sunlight nearly continuously — approximately 99% of the year — without clouds, nighttime, or atmospheric losses. This is fundamentally different from terrestrial solar, which is limited by daily cycles and weather. The SBSP concept was formally proposed by Peter Glaser in 1968 and has been studied by NASA, the U.S. Department of Energy, ESA, JAXA, and academic institutions. As of 2026, no commercial SBSP system has been deployed. The technology is at varying readiness levels across its component subsystems.