In a development that brings space-based power generation systems a step closer to reality, researchers from the Japan Aerospace Exploration Agency (JAXA) and the Osaka University Institute of Laser Engineering have developed groundbreaking new technology for converting sunlight into laser beams.
Relying on plates made from a special ceramic material containing chromium (which absorbs the sunlight) and neodymium (which efficiently converts sunlight to laser light), the newly developed lasers demonstrated an impressive 42% solar-to-laser energy conversion efficiency, outperforming previous technology by a factor of four.
The researchers say the new laser technology will play a key role in JAXA's "Space Solar Power Systems" (SSPS) project, which aims to put space-based power systems in orbit by the year 2030. By mounting the system on a satellite in stationary orbit 36,000 km (22,400 mi.) above the equator, sunlight would be collected and converted into a powerful laser beam, which would then be aimed at a terrestrial power station and used to generate electricity or produce hydrogen.
Unlike earthbound solar power stations, which are subject to night-time darkness and cloudy conditions, JAXA's SSPS will be able to make use of solar energy 24 hours a day. With slight improvements in the solar-to-laser conversion efficiency and by incorporating solar collectors measuring 100 to 200 meters long, a single satellite will be able to match the output of a 1-gigawatt nuclear power plant, the researchers say. One can only hope these lasers never fall into the wrong hands.
The results of the research were announced at a meeting of the Japan Society of Applied Physics that began on September 4 in Sapporo.