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.

Earlier this year, the UK government announced, external £3m in funding for space-based solar power (SBSP) projects, following an engineering study conducted by consultancy Frazer-Nash that concluded the technology was viable.

SEI is hoping to get a big chunk of that money.

Its satellites would be made up of hundreds of thousands of small, identical modules produced in factories on Earth, and assembled in space by autonomous robots, who would also carry out servicing and maintenance.

The solar energy collected by the satellites would be converted into high frequency radio waves and beamed to a rectifying antenna on Earth, which would convert the radio waves into electricity.

Each satellite could deliver around 2GW of power into the grid, making each satellite comparable in power output to a nuclear power station.

Here on Earth, sunlight is diffused by the atmosphere, but in space it comes directly from the sun without interference.

So a space-based solar panel can collect a lot more energy than a similar sized one on Earth.

Similar projects are under development elsewhere.