Could space-based solar farms soon be a reality? | Solar power

The British astronaut Tim Peake is backing the idea of solar farms in space, using satellites to capture solar energy and beam it down as microwaves to ground stations. A satellite in geostationary orbit about 36,000km (22,700 miles) above Earth could generate solar power almost all day, every day, whatever the weather, as well as collecting sunlight more intense than on the Earth’s surface.

The microwaves beamed down would be unhindered by clouds, although the beam would need to be restricted to avoid harming anything that got in the way, before being collected by large receivers that would convert the microwaves into electricity.

It sounds like something from a Star Trek episode, but in June a prototype designed by Caltech successfully beamed a small amount of power to Earth. While the prototype worked, it is difficult to envisage a power station in space being economically viable – an entirely new energy infrastructure would need to go into space.

The biggest challenge would be launching the tonnes of material into space needed for the satellite as well as further launches to service and refuel the satellite to extend its lifespan. The Falcon rocket designed by Elon Musk’s Space X can lift the loads but would need hundreds of launches – too expensive to be economic. Although the test flight of another Space X rocket, the Starship, exploded, the rocket, which is designed for far heavier payloads, might end up cheaper.