Microwave Power Transmission Research Papers (original) (raw)

Summary form only given. Over the past 35 years, research has progressed on many aspects of space-based solar power supply to Earth. However, cumulative funding of this research remains several orders of magnitude less than that of other energy sources, including terrestrial solar power systems. In addition, a power pilot plant has not yet been built and operated; yet until a pilot plant is built, it will not be possible to fully evaluate the system's potential to become a major, environmentally benign source of electric power during the 21st century. Work in Japan on space-based solar power supply to Earth began in 1980. As expertise in the subject grew, the SPS Working Group was established at the Institute of Space and Astronautical Science (ISAS) to coordinate a number of projects. Among these, the project that grew into the largest single coordinated body of work concerning space-based solar power in Japan was the design of a 10 MW pilot plant satellite for operation in low equatorial orbit. This project, which became known as "SPS 2000", was first described in detail in 1991 by Professors Makoto Nagatomo and Kiyohiko Itoh in a paper at the "SPS91" international conference in Paris. That paper established a set of guidelines for the project, which included that the system should supply power to consumers, in order to generate real user feedback. As a related part of the project, the authors received a series of grants from the Japanese Ministry of Education and Science to visit countries near the equator to research the possibility of siting rectennae (rectifying antennae) in their territory and deliver microwave power from space for local use. These countries welcomed the proposal, and are keen to see the project realised. In addition, the project has received praise in many expert reports around the world. To date, a major conclusion of the technical work on the SPS 2000 satellite design is that the main technical challenge seems to be the robotic assembly in orbit. Unless there is some potential for human intervention in the event of problems it is very difficult to have confidence that the 200 ton satellite, carrying some 10 hectares of solar cells could deploy itself automatically without problems. Studies on space-based solar power have re- ached the stage at which production and operation of a pilot plant is now the most appropriate next step. However, space agencies in USA, Europe and Japan decline to fund this work, since energy policy is not their responsibility. The decision to minimise funding of space-based solar power research to date is thus not a considered conclusion of targeted policy studies, but a by-product of government institutional arrangements whereby energy policy and space technology are controlled by separate branches of government. There is an urgent need for this governmental obstacle to be removed, and for a space-based solar power pilot plant to be put into operation.