The Daily Mail is reporting a Japanese company, Shimizu, has unveiled a plan to turn the moon into a giant solar collector. The idea, which is not new, has achieved some resonance due to the Fukushima nuclear disaster.
Shimizu is proposing to ring the moon's equator with solar collectors. These collectors would absorb sunlight that is unfiltered by the Earth's atmosphere. The energy thus collected would be beamed to collecting stations on Earth, perhaps through relay satellites, then transmitted into the power grid.
The plan by Shimizu envisions a ring of solar collectors 6,800 miles long and 240 miles wide. The Japanese concept would involve a 12 mile-wide antennae transmitting 13,000 terawatts of continuous energy to a receiving station on Earth. (The 13,000 terawatts figure may be a result of some confusion on the part of the Daily Mail. That figure is the amount of solar energy received by the entire surface of the moon.)
The Shimizu plan appears to be based on a concept developed by David Criswell, director of the University of Houston's Institute for Space Systems Operations. Criswell set down his idea in a paper entitled "Solar Power via the Moon."
The plan involves building a series of collecting stations situated around the moon, with antennae that would transmit the power thus received through microwaves via a series of relay satellites to a number of receiving stations or rectennas on the Earth's surface. Each microwave beam would have a maximum intensity of about 20 percent of noontime sunlight and would deliver 200 watts for every square meter of rectenna area. The entire system would transmit 20 terawatts of clean energy to Earth, enough Criswell's estimates to provide for the needs of 10 billion people at current technology. The lunar part of the infrastructure would be built using primarily local materials.
Turning the moon into a giant solar collector would be the greatest public works project in the history of humankind. It would involve many years of work using human and robotic workers on the lunar surface. At the end, if Criswell and Shimizu are correct, the energy problem on Earth will have been solved. Combined with terrestrial sources of energy, a lunar-based solar power scheme would transform human civilization in ways that can only be dimly imagined.
Ideas like Criswell's and Shimizu should become part of the mix as the debate over America's future direction in space grinds on. Thus far, the plan set forth by President Obama would bypass the Moon. That decision may well have been both premature and ill advised.
Mark R. Whittington is the author of Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post, USA Today, the L.A. Times, and The Weekly.