James Montgomery, Associate Editor, RenewableEnergyWorld.com
December 26, 2013 | 7 Comments
To the Moon!
Since solar energy comes from the sun, why not cut out part of the middleman? Japanese engineering and construction firm Shimizu envisions the "Luna Ring," a 11,000-km belt of solar panels encircling the moon's equator, in a width from just "a few kilometers to 400 km." Power harvested from the sun would be transmitted via to enormous (20-km diameter) wireless antennas, and shot out to earth via 20-GHz microwaves, with radio beacons ensuring accurate transmission. Alongside, high-density lasers would be beamed to offshore facilities on Earth to be concentrated by a Fresnel lens and mirrors to generate solar PV power; the lasers' thermal energy would be harvested as well. Receivers and massive cabling on Earth would convert all of that into electric power, to be supplied to grids and for conversion of hydrogen. The moon itself would be tapped to produce resources to make the solar cells and panels and construction materials. Robots would perform most of the tasks, and the equipment would be assembled in space and lowered to the surface for installation.
The Luna Ring reportedly would supply up to 13,000 terawatts of power, or what Shimizu says would match the world's energy demand by 2030. Exploration would begin within the next few years, followed by a pilot demo both on Earth and the moon in the next decade, and construction beginning in 2035.
If lunar solar installs seem a bit too risky, how about orbiting solar projects? One company has NASA backing to use robots for building structures in orbit... using the most popular concept running, "additive manufacturing" -- essentially melting a metal (or plastics, in less fancy versions) in precise patterns to build up a tough finished product. The Trusselator and the "SpiderFab" would enable fabrication of carbon fiber truss structures, including solar arrays and other structures like antennae and transmitters with "kilometer-scale apertures," to help enable lower-cost space exploration and development.
Image credit: Shimizu