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Can Earth Be Powered by Energy Beamed From Moon?

Bijal P Trivedi
for National Geographic Today
April 26, 2002
 
If beaming solar power to Earth by way of the moon sounds like lunacy, consider this: It could provide a clean, emission-free, and unlimited source of energy. And, according to David Criswell, a physicist and Space Age veteran, it could supply all needs of an energy-hungry world in the 21st century and beyond.

"We think of beaming power from the moon as exotic, but it has been done for at least 15 years," says Criswell, director of the Institute for Space Systems Operations at the University of Houston. "Power beaming is like using a big radar."



Criswell proposes a Lunar Solar Power System (LSP), using lunar materials to build bases on the moon to collect solar energy and convert it to microwaves, which would be beamed to a several thousand receivers around Earth. The microwaves would then be converted into electricity to be fed into local power grids.

Successful Earth-moon power beams are already in use, he points out in the current issue of The Industrial Physicist. A radio telescope operating from the Arecibo Observatory in Puerto Rico regularly uses a beam of microwaves to produce images of the moon.

"In principle it is perfectly feasible, but the problem is cost," says Paul Lowman, a geologist at NASA's Goddard Space Flight Center. "Criswell's project will need a lot of people up there, and that will be expensive."

"Right now we have trouble funding the International Space Station (ISS), with all of its important research projects," says former senator and astronaut John Glenn. "To go back to the moon, establish and keep viable bases for power generation would be a very, very expensive operation. I would rather see more funding to support ISS."

Moon-Based Power Grid

The proposed LSP System would consist of between 20 and 40 power bases located on the eastern and western edge of the moon, as seen from Earth. Criswell estimates that in 2050, a population of about 10 billion would require about 20 terawatts of power.

The moon receives more than 13,000 terawatts of solar power, and harnessing just one percent could satisfy Earth's power needs, he says.

"I think it is a problem that we haven't been to the moon in 30 years, and we don't have a clear idea how to utilize the moon's resources," says Martin Hoffert, a physicist at New York University and co-author of Beam It Down: How the New Satellites Can Power the World. "But from a technical point of view, it would probably work."

Criswell began pondering lunar-based power systems more than 20 years ago during a decade-long stint at the Lunar Science Institute, now the Lunar and Planetary Institute, which was established in 1967 by Lyndon Johnson to maintain interest in the moon.

While he was at the institute he participated in the administration of peer-reviewed proposals on lunar and planetary science, which gave him constant exposure to lunar-related research and development.

After Criswell got a modest grant from NASA's Langley Research Center for another project—to investigate the conversion of lunar matter into engineering materials, such as bauxite into aluminum—he became confident "that we had the skills as a nation and as the world to use resources on the moon."

Criswell also points out that the moon rocks that received so much publicity weren't just souvenirs. During the 1970s and 1980s, between half a billion and a billion dollars was spent to analyze the rocks collected during the six Apollo moon landings. Analyses revealed an abundance of silicon, magnesium, aluminum, and titanium—the basic material required for building solar cells.

Road Block on Moon Journey

Criswell says that the machinery to make solar cells could be made from lunar materials or transported from Earth.

"We are not talking about taking a GM factory to the moon," says Criswell. "We are talking about machinery more on the scale of road-building equipment—roughly ten to 20 times the size of the lunar rover." The machines would move dirt around, extract metal from the soil, and produce and lay out the thin glass solar cells.

But lunar power would require a return to the moon, and currently there are no active plans for such a mission, says Glenn.

Lowman adds, "As far as NASA's concerned, the moon has been scratched off. Scientists' interests have shifted to astrobiology, life on Mars, Europa." Only if carbon dioxide is shown to be escalating global warming will there be pressure to move energy production to the moon, he says.

"Between 30 and 40 percent of people on the planet are not connected to a power grid," says Hoffert. "The problem with alternative energy sources, like wind and solar power, is that they are intermittent, and it is difficult to transfer the power to places where you need it and when you need it.

"Beaming energy from satellites or the moon to people in developing countries could be a way of jump-starting power distribution," he says.

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