The Japanese firm Shimizu, one of the largest architectural, engineering, and construction firms in the world, has drawn up plans to install a ring of solar panels around the moon’s equator http://bit.ly/1bfgLct . The collected energy would be beamed back to Earth. While this strikes me as a publicity stunt, it is an intriguing idea. The benefits are easy to see: no power plants fueled by coal or gas or uranium; no mining for those resources either. No acres of solar panels or ridges lined with wind turbines. Power receiving stations could be scattered around every nation, reducing the need for large transmission lines. Cost savings would be big.
Problems would be even bigger. Receiving stations will be out of range about half the time, so maybe we’ll still need to generate on Earth’s surface. Half the panels will be on the night-side of the moon at any given moment, lowering overall efficiency. The installation will be vastly expensive. For the 6,800 mile length of the lunar equator, Shimizu proposes a width of 248 miles. That will require 1,686,400 square miles of solar panels, which Shimizu claims would generate 13,000 terawatts. At a cost for panels of $0.65/watt (and I’ve seen higher estimates), that’s roughly $6,500,000,000,000,000. That’s $6.5 quadrillion (I had to look it up), and it’s just for buying panels here on Earth.
It’s still intriguing. How would we run such a project? First we’d need a station that can safely receive the power. Then we’d want a factory to manufacture the panels on the Moon. And robots to install and maintain the panels. We’d start small. Imagine a robotic factory with half its output being another robotic factory. Just leave it churning away on the Moon. Someday, the entire surface could be covered in panels. If they were exceptionally efficient and absorbed all wavelengths of visible light, we’d never see the Moon from Earth again.
Would we owe rent to anyone for the installation? The United Nations 1967 publication “Outer Space Treaty” states space is the “province of all mankind” and not subject to claims of sovereignty. The international Moon Treaty of 1984 forbids private ownership of extraterrestrial real estate. (Sorry – that deed to an acre of the Moon you got for your birthday is just a gag.) But I bet lots of people would want a say in the project.
So I think Shimizu is pulling a stunt, but maybe it foreshadows a real project in the future. Maybe thinking outside the box means thinking outside the planet.