Mitsubishi Heavy says ground test validates wireless power transmission for space solar power systems; 10 kW sent 500m by microwave
Mitsubishi Heavy Industries, Ltd. (MHI) successfully conducted ground demonstration testing of “wireless power transmission,” a new technology presently under development to serve as the core technology of space solar power systems (SSPS). (Earlier post.) In the ground demonstration test, 10 kW of power was sent from a transmitting unit by microwave; the reception of power was confirmed at a receiver unit located at a distance of 500 meters (m) away by the illumination of LED lights, using part of power transmitted.
The transmission distance and power load mark new milestones in Japan with respect to length and volume of wireless power transmission. The testing also confirmed the performance of the advanced control system technology used to regulate the direction of the microwave beam so that it does not veer from the targeted receiver unit.
MHI conducted the ground demonstration testing based on an agreement with Japan Space Systems, the incorporated foundation that has been consigned by the Japanese Ministry of Economy, Trade and Industry to carry out the “2012 Solar Power Wireless Transmission Technology Development Project.”
Wireless power transmission technology aims to eliminate the cable connections conventionally necessary for transmitting electricity; the newly successful test results lead the way to applying the technology in numerous terrestrial fields. The achievement of wireless power transmission over long distances will not only facilitate the transmission of power to locations where installation of power cables has been difficult or dangerous, but is also expected to contribute to transmission of power from offshore wind turbines and various other applications in the future. One readily conceivable application is wireless transmission of power to electric vehicles.
The Japan Aerospace Exploration Agency (JAXA) has been conducting studies on both microwave- and laser-based Space Solar Power Systems (SSPS) for years, organizing a special committee and working groups.
In case of microwave based SSPS (M-SSPS), the solar energy must be converted to electricity and then converted to a microwave beam. The on-ground rectifying antenna would collect the microwave beam and convert it to electricity to connect to commercial power grids.
In the laser-based SSPS (L-SSPS), a solar condenser equipped with lenses or mirrors and laser-generator would be put into orbit. A laser beam would be sent to Earth-based hydrogen generating device.
Takanori Narita, Keiji Suzuki, Mayuki Niitsu, Toshihiro Kamiya, Kenichi Anma, Nobuhiko Fukuda (2011) “The Development of Space Solar Power System Technologies” Mitsubishi Heavy Industries Technical Review Vol. 48 No. 4
Narita, T.; Kimura, T.; Anma, K.; Fukuda, N.; Shinohara, N. “Development of high accuracy phase control method for space solar power system,” Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications (IMWS), 2011 IEEE MTT-S International doi: 10.1109/IMWS.2011.5877136