Wireless Power Transmission

Wireless power transmission (WPT) is the transfer of electrical energy from a source to a receiver without physical conductors, using electromagnetic radiation as the transmission medium. In the context of space-based solar power, WPT refers to the transmission of energy from an orbital platform to a terrestrial receiving station using either microwave frequencies (typically 2.45 GHz or 5.8 GHz) or laser wavelengths. WPT was demonstrated at laboratory scale in the 1960s and 1970s. Subsequent demonstrations have proven the basic physics at progressively larger scales. However, the efficiency, pointing precision, and beam-forming requirements for a full-scale SBSP system transmitting from geostationary orbit have not yet been demonstrated. End-to-end efficiency — from solar input to grid output — remains a critical metric and an area of active research.