I’ve written recently about the potential to generate electricity via solar power generation in the deserts of northern Africa that can then be transmitted to and consumed by Europe. Now there is a new, somewhat less realistic but nonetheless intriguing, proposal by Shimizu Corporation in japan to generate electricity on the Moon and then beam it back to Earth. The Luna Ring.

The proposal would be to establish a band of solar cells around the Equator of the Moon, the area which, like on Earth, is exposed to the most sunlight throughout the year. Such a band would need to be 11,000kms long to completely circumnavigate our nearest neighbour and the proposal is for it to be up to 400km wide.

The electricity generated would be transmitted to a point on the near side of the Moon (the Moon is in synchronous rotation around Earth, always showing the same face to us) where it could be converted to microwave or laser before being beamed back to Earth. These beams would be aimed at collectors on Earth which would convert it back to electricity and feed it into the grid. Obviously the Moon does not stay above the same part of the Earth at all times so the collectors would need to be distributed around the planet. In addition, a guidance beacon would ensure the laser/microwaves are hitting their intended target otherwise the power would be cut. It is not difficult to imagine scenes of a giant space laser cutting a swathe through New York City (it’s always NYC in the movies) without such a safety device.

A solar belt around the Moon would theoretically provide more than enough clean energy for all of humanity.

You might wonder why we don’t just build solar farms all around the Earth’s Equator instead as surely that would be simpler than trying to do it on the Moon. There are several reasons.

1. The Earth has a thick atmosphere which significantly reduces the amount of the Sun’s energy reaching the surface (luckily for us) whereas the Moon does not. Solar generation on the Moon would thus be vastly more efficient.
2. 70% of the Earth is covered with water and at the Equator that figure is actually 78.7% water. This makes for a fairly intermittent solar belt.
3. The Equatorial land is largely all in use already. Countries in Central America and South-East Asia are densely populated. The northern African deserts are about the only options.

The plan is that most of the infrastructure on the Moon could be built by robots using materials sourced there such as silica to avoid the cost and difficulty of shipping materials from Earth. It’s likely that such an endeavour will not be undertaken in the next 100 years but I applaud the concept and feel that we should always be looking ahead to future solutions even while we work on current solutions with the technology at our disposal.

There have already been concepts involving large solar energy collecting satellites that would also beam the energy back to Earth and these could perhaps be implemented in the shorter term. Meanwhile we must persist with finding more terrestrial solutions for clean energy generation. Certainly don’t dismiss any of these ideas as crazy as people from 100 years ago would never have been able to imagine the technology we have today.

Source: http://www.treehugger.com/files/2010/06/luna-ring-solar-power-plant-on-the-moon.php

Source: http://www.shimz.co.jp/english/theme/dream/lunaring.html