Physicist Wants to Harness Energy From the Moon

April 22, 2002 -- David Criswell has been waiting for an energy crisis.

It's not that he particularly wants an energy shortage, it's just he's excited about an alternative: Drawing solar energy from the moon.

"Oil in Alaska is nothing compared to what you'd get from the moon," said Criswell, a physicist at the University of Houston Institute for Space Systems, who has been promoting his idea steadily for about 20 years. "This kind of energy would be available as long as the sun shines and the moon is up there."

Plugging Into the Moon

In this month's issue of The Industrial Physicist, Criswell lays out his plan to build solar panels and micro transmitters from lunar materials and begin beaming solar energy to Earth.

Solar panels would convert the sun's rays to energy and transmit it through buried wires to microwave generators. The generators would then convert the energy into harmless microwave beams, which would be aimed at collecting stations on Earth. At Earth, they'd be converted back into electricity.

The 20-40 lunar power bases would be stationed at the east and west edges of the moon so one or the other would always be sunlit as the moon travels around the Earth. Earth-orbiting satellites and mirrors could also help aim the beams towards the terrestrial antennas. None of the moon-based solar units, he says, would be visible with a naked eye from Earth.

"It would be like having an electric cord stretched across the solar system," he said.

Sending material to space is not cheap, so Criswell has studied lunar rocks collected during the Apollo mission years and determined that 90 percent of the aluminum, silicon and glass needed to build solar power plants can be found on the moon.

Still, the initial costs of building the lunar solar power stations remain steep. Criswell estimates it would take about $15 billion to launch the project and then about $135 billion more before the investment begins to break even.

"It would require the efforts of many nations and a treaty to do it," he said.

An Expensive Sell

Criswell, who managed a NASA review of thousands of lunar studies in the 1980s, calculates with the same focus applied to NASA's Apollo mission, the lunar power project could be up and running in 10 year's time.

Then, he says, the world would have access to a limitless power supply. The moon receives 13,000 terrawatts of power from the sun. Harnessing 1 percent of that energy, he calculates, could replace all fossil fuel power plants on Earth.

"As far as I can tell, what we need is abundant, clean energy that's low in cost so developing nations can afford it," he said. "I don't see any other way to do it."

Criswell has published nearly 200 articles on the subject and pitched it at conferences and colleges, as well as to NASA managers. Although many have expressed interest in the idea, so far, no one has offered to back it up with funding.

John Mankins, NASA's manager for advanced concept studies, has said a lunar solar project might easily become more expensive than expected since missions to space often are. A more realistic idea, he suggests, could be placing sun-facing photovoltaic arrays in stationary Earth orbit. Arrays at an altitude of 22,300 miles would receive eight times as much sunlight as they would at the Earth's surface, on average.

Criswell believes lunar solar panels are more practical since they wouldn't be adding to the already accumulating level of debris in space.

"It's clear the first step is a large one compared to other commercial investments," he said. "We'd need a redirection in our space program. But I think everything else is secondary to establishing a limitless energy supply."