• Hideo Matsuoka
• Makoto Nagatomo
• Patrick Collins

After more than 30 years of research into the possibility of delivering environmentally benign, solar-generated microwave power from satellites in Earth orbit to dedicated receiving antennas on Earth, a pilot plant is now needed to demonstrate its feasibility. This will be far more convincing to engineers from the electricity generation industry that the technology of this system is mature than theoretical explanations or technology demonstrations in space.

A 10MW solar power satellite (SPS) pilot plant is being designed in Japan that will operate in orbit 1100 km above the equator and provide the first supply of electric power for thousands of homes among the poorest regions of the Earth. In doing so it will also generate a wealth of data on SPS system operations, and provide a test-bed that electricity supply companies will be able to use to perform a range of experiments that they need to be convinced of the system's feasibility.

To date the authors have made field research visits to ten developing countries along the equator, meeting government officials and researchers, and visiting candidate sites for microwave power receiving antennas (rectennas) of up to about 1 km in diameter. All the countries visited have expressed keen interest in participating in the project, and more detailed case studies of each candidate rectenna site are being planned. It is highly desirable from many points of view that the economically more advanced countries should collaborate with the less developed countries near the equator to bring this project to reality.