Space-based Solar Power
What are Solar Power Satellites?
Solar Power Satellites (SPS) are fairly large structures in space that convert solar energy, captured as solar irradiation, into an energy form that can be transmitted wirelessly (Wireless Power Transmission - WPT) to any remote location with a receiver station, either on Earth, to high altitude platforms, to other spacecraft or even to surfaces of the moon or other planets. This idea has a long history, for an overview see this table.
Why go into space instead of building them on Earth?
The big advantage of space based solar power collection is the 24h availability: unlike the situation on the surface of Earth, in geostationary orbit there is no night and the sun is never shadowed by clouds, rain or fog. Since we are using energy day and night, the continuous power generation in space makes large and expensive energy storage devices superficial. But the final trade-off depends on many more parameters that are subject of the study started by the Advanced Concepts Team.
How is the power transmitted to Earth?
Currently the so-called reference design transforms solar power into electricity via photovoltaic cells in geostationary orbit around Earth. The power is then transmitted via electromagnetic waves at 2.45 GHz to dedicated receiver stations on Earth, "rectennas", which convert the energy back into electricity used in the local grid.
How much power can solar power satellites deliver?
The power range of the concepts for SPS is from a few tens of MW to several hundred of GW. Just for comparison purposes, a modern standard nuclear power plant delivers about 1 GW and the energy need for Europe in 2020 is estimated to be about 500 GW. If we can come close to the theoretical transmission efficiencies via electromagnetic waves (50-60%) then we could continuously receive 75-100 W electricity per square meter of space PV panel in our terrestrial electrical grid, which is about three to four times the amount we could receive from the same area of terrestrial PV panel.
Since 2012, the the International Astronautical Federation (IAF) Space Power Committee is organising together with the the Space Generation Advisory Council (SGAC), the IAF Space Education and Outreach Committee and the IAF Workforce Development/Young Professional Programme Committee the a 2000$ paper competition for students and young professionals. For more information on the competitions
All activities in the field are regularly published at different international conferences. Please find a list of selected publications on the Studies and publications page.
See also: The Furoshiki project on how to build large structures in space.