Can we get electricity for Earth by putting solar panels in space? A new analysis suggests that one of the major problems can actually be overcome.
The scientist Peter Glaser first proposed the idea of putting solar panels in space back in the 1960s. It goes like this: You put satellites into orbit with solar panels on them. Sunlight hits the panels, making electric power. That electric power is then turned into microwaves and beamed to large "rectennas" on Earth that convert it back into electricity.
This idea has a lot going for it. In space there aren't clouds and there's no night, so you can get sunlight 24/7. Energy harvested by satellites could, in theory, scale up to meet the needs of our entire civilization.
The big challenge is just getting all this equipment into orbit at a reasonable cost. Using conventional rockets to get solar satellites into space is way too expensive if the energy we're hoping to produce is going to compete with coal.
But a detailed new analysis from the energy blog The Oil Drum has a solution. It relies on the Skylon, a rocket plane being developed by Reaction Engines, and a system of ground-based lasers that would hit the plane on its way into orbit, heating hydrogen on board to provide an extra burst of acceleration. This would allow the plane to get satellite components into space for under $100 per kilogram, making the total cost of solar energy from space as low as 2 cents per kilowatt-hour, half the price of coal.
This new analysis is speculative, of course, and filled with assumptions, but hey, so was the idea of nuclear power at some point. Solar power from space might be closer than we think.