"If Earth is to prosper 50 years from now, it will need five times the energy it is producing today at one-tenth the cost. And Houston physicist David Criswell knows exactly how to do it: beam sunshine down from the Moon! ...more...

Solar energy coming at us in a never-ending stream is the cleanest, safest, cheapest way to achieve such an objective, according to Dr. Criswell, director of the Institute for Space Systems Operation at the University of Houston. It may also be the only way.

Writing in the latest issue of The Industrial Physicist magazine, Dr. Criswell says a Lunar Solar Power (LSP) system using an array of solar cells built on the Moon with lunar materials and beamed to Earth as microwaves would be enough to satisfy the earthly appetite for power. He estimates 10 billion people living on Earth in 2050 would need 20 terrawatts of power. Since the Moon receives 13,000 watts from the Sun, just
one per cent of that would have to be directed to Earth to give us all the power we would require.

``Currently, commercial energy production on Earth raises concerns about pollution, safety, reliability of supply and cost,`` Dr. Criswell says. ``These concerns grow as the world`s nations begin to expand existing systems to power a more prosperous world. ``Such growth could exhaust coal, oil and natural gas reserves in less than a century, while the production and burning of these fossil fuels pollute the biosphere.``

The ability to achieve solar power via the Moon is not as far-fetched as it might seem. Dr. Criswell says as much as 95 per cent of the material necessary to build lunar power bases are available on the Moon itself. Handsful of lunar soil contain silicon, aluminum and iron that can be extracted chemically and used to fabricate solar cells. Bulk and separated soil can be melted using the sun`s power and formed into thin glass sheets and fibres, tubes and bricks.

Now you can begin to build the LSP system. It uses as many as 20 pairs of bases, one part being placed on the west edge of the Moon and its partner on the east edge as seen from Earth. At each base, sunlight hits a solar converter, which passes on the resulting power via underground wires to the microwave generator. This generator then lights up a microwave reflector which sends off a continuous stream of microwaves to Earth where it is captured by rectifying antennas (rectennas) that turn those waves back into
electricity.

Dr Criswell says in order for there to be energy prosperity around the world, about 100,000 square kilometres of rectennas would be required, which
he considers tiny when compared with Earth`s 100 million square kilometres.

``Five out of six people on earth are poor and they are the ones that need it,`` he says. ``But environmental damage is getting worse and the new
generation of global consumers know we have to find a different way to go about finding energy.`` He says the technology is there. NASA spent $47 million in the 1970s studying the making of solar power satellite pieces on earth, launching them into space and putting them together. The space administration also
sponsored MIT research into making the components from lunar material.