1 A US-INDIA POWER EXCHANGE TOWARDS A SPACE POWER GRID

Abstract — The Space Power Grid (SPG) architecture described in papers from our group since 2006, is an evolutionary approach to realizing the global dream of Space Solar Power (SSP). SPG first concentrates on helping terrestrial power plants become viable, aligning with public policy priorities. It enables a real-time power exchange through Space to help locate new plants at ideal but remote sites, smooth supply fluctuations, reach high-valued markets, and achieve baseload status. With retail cost kept to moderate levels, a constellation grows in 17 years to 100 power relay satellites at 2000 km sun-synchronous and equatorial orbits and 250 terrestrial plants, exchanging beamed power at 220GHz. In another 23 years, power collection satellites replacing the initial constellation will convert sunlight focused from ultralight collectors in high orbits and add it to the beamed power infrastructure, growing SSP to nearly 4 TWe with wholesale and retail delivery. The SPG-based SSP system can break even at a healthy return on investment, modest development funding, and realistic launch costs. The immense launch cost risk in GEO-based SSP architectures is exchanged for the moderate risk in developing efficient millimeter wave technology and dynamic beam pointing in the next decade. A US-India space-based power exchange demonstration would constitute a rational first step towards a global SPG. We discuss two options to achieve near-24-hour power exchange: 1) 4 to 6 satellites at 5500km near-equatoria