Advanced space technology for 21st century energy systems: solar power from space

Terrestrial solar power is one of the fastest growing energy sectors with high growth rates sustained over more than a decade (especially in Europe) and very promising forecasts. For 30 years, the idea of a large solar power plant in Earth orbit, transmitting energy to Earth-bound receiver sites, has enjoyed periodic attention from energy and space entities. All studies concluded the principal technical feasibility of the concepts and gradually improved their power to mass ratio. No substantial development efforts were undertaken, however, since, with current technology, space generated electricity costs would still be too high, upfront costs prohibitive and the launcher sector not mature enough to reduce €/kg to orbit costs by the required order of magnitude. In the past, space concepts were mainly compared to traditional energy systems. Based on this background, the Advanced Concepts Team (ACT) at the European Space Agency started a three-phased programme in 2003. The first phase of the programme, the validation phase, focused on a comparison of a space solar power plant with comparable terrestrial solutions, on the one hand, and the assessment of the potential of SPS for space exploration and space application, on the other. Space concepts were compared to terrestrial solutions based on equally advanced technology and equal economic conditions for the timeframe 2020/30 in terms of energy payback times, final €/kWh generation costs, adaptability to different energy scenarios, reliability and risk.