BBC News: How Solar Farms in Space might beam electricity to Earth

It sounds too good to be true: a plan to harvest solar energy from space and beam it down to Earth using microwaves.

But it’s something that could be happening as soon as 2035, according to Martin Soltau, the co-chairman at Space Energy Initiative (SEI) – a collaboration of industry and academics. SEI is working on a project called Cassiopeia, which plans to place a constellation of very large satellites in a high Earth orbit.

Once deployed the satellites would harvest solar energy and beam it back down to Earth. He says the potential is almost unlimited.

In theory it could supply all of the world’s energy in 2050,” he says. “There’s sufficient room in orbit for the solar power satellites, and the Sun’s supply of energy is vast. A narrow strip around geostationary Earth orbit receives more than 100 times the amount of energy per year than all of humanity is forecast to use in 2050,” Mr Soltau says.