This document discusses space-based solar power satellites (SPS) that would collect solar energy in space and transmit it to Earth via wireless power transmission (WPT). It outlines important milestones in the development of this technology, including early experiments in the 1900s and proposals from the 1960s onward. The document describes the basic design of an SPS, including using large solar arrays in low Earth orbit to generate 5-10 gigawatts of power and transmitting it to rectennas on Earth via microwave beams. It also discusses challenges such as high launch costs and the need for international cooperation, as well as advantages like continuous power generation and fewer land use impacts compared to terrestrial solar.
15. The power-collecting platforms would most likely operate in geosynchronous orbit where they would be illuminated 24 hours a day
16.
17. 1968: Dr .Peter Glaser introduced the idea of a large solar power satellite system with square miles of solar collectors in high geo synchronous orbit
18. 1973: Dr. Peter Glaser was granted U.S. patent number 3,781,647 for his method of transmitting power over long distances
19. 1994: The United States Air Force conducted the Advanced Photovoltaic Experiment using a satellite launched into low Earth orbit by a Pegasus rocket
22. 2001: NASDA (Japan's national space agency) announced plans to perform additional research and prototyping by launching an experimental satellite with 10 kilowatts and 1 megawatt of power
23. 2009: Japan announced plans to orbit solar power satellites that will transmit energy back to earth via microwaves. They hope to have the first prototype orbiting by 2030
37. The transmission is through space and atmosphere and received on earth by a huge antenna called the rectenna.
38. Recent developments suggest the usage of recently developed solid state lasers allow efficient transfer of power.
39.
40. For receiving these transmitted waves rectennas are set up at the Earth. An antenna comprising a mesh of dipoles and diodes for absorbing microwave energy from a transmitter and converting it into electric power. Microwaves are received with about 85% efficiency and 95% of the beam will fall on the rectenna but the rectenna is around 5km across . Currently there are two different design types being looked at- Wire mesh reflector and Magic carpet.
58. The large scale of Space Solar Power will require international financing
59. Technology for an efficient wireless power transfer is still in the evolving stage
60.
61. Solar power satellites in low-Earth or geosynchronous orbit or on the Moon to supply terrestrial power demands on a global scale.
62. High-altitude, long-endurance aircraft maintained at a desired location for weeks or months at 20 km for communications and surveillance instead of satellites, at greatly reduced costs.
63. Power is transmitted from distant sites to geosynchronous orbit and then reflected to a receiver on Earth in a desired location very economically without overhead lines.
64.
65. SPS is still more expensive than Earth-based solar power and other energy sources. Yet, even now, a small SPS system could be economically justified to provide otherwise unavailable emergency power for natural disaster situations, urban blackouts and satellite power failures Wireless power transmission is still being considered as a next-generation power transmission system for the future
66. REFERENCES IEEE International Symposium on Antennas and Propagation, April 20, 2010 World Energy Council, "Energy for Tomorrow’s World - Acting Now", WEC Statement 2000, www.worldenergy.org. WEC/IIASA, Global Energy Perspectives, Nakicenovic, Nebojsa, et al, Cambridge University Press, 1998.