Overview Energy wants to beam power from space to existing solar farms

Overview Energy emerged from stealth today with a plan to use the world’s solar panels as nightly collectors of energy emitted from space.

The startup plans to use large solar arrays in geosynchronous orbit — about 22,000 miles above Earth, where the satellites match the planet’s rotation — to collect sunlight. It will then use infrared lasers to transmit that power to large-scale solar farms on Earth, allowing them to send power to the grid almost around the clock.

Overview has raised $20 million to date, and some of that money has gone toward an airborne demonstration of power radiation technology. A light aircraft transmitted power using a laser to a ground receiver at a distance of 5 km (3 mi).

Investors include Aurelia Institute, Earthrise Ventures, Engine Ventures, EQT Foundation, Lowercarbon Capital and Prime Movers Lab.

As the cost of launching into space has come down over the past decade or so, space-based power has gone from pure science fiction to something closer to reality.

There are still many hurdles to overcome: For one, it’s still much cheaper to install solar panels here on Earth than to send them into space. And the ability to send power wirelessly from orbit to the surface of our planet is still in its infancy.

And other companies are attempting the same feat. Aetherflux is also pursuing a laser-based approach. Others, such as Emrod and Orbital Composites/Virtus Solis, are developing microwave-based power transmission, which sends energy wirelessly using a different part of the electromagnetic spectrum than Aetherflux and Overview.

Microwaves are less sensitive to clouds and moisture than infrared lasers, which cannot transmit in cloudy weather, as suspended water droplets would absorb much of the energy. But because microwave-based systems can’t reuse existing solar farms, they’ll have to build their own ground stations.

To keep costs down, these ground receivers would probably be smaller, so the energy beams would have to be tighter and more powerful. Companies are developing ways to quickly interrupt the beam to prevent collateral damage to birds and aircraft, but it’s still a concern.

The Review’s repurposing of solar farms will alleviate some of these concerns, although it will need to convince the public that energy beams from space are safe and won’t miss the target. (Remember SimCity 2000?) The company should also ensure that its laser system is very efficient. Otherwise the benefit of collecting sunlight in space will evaporate as the energy is converted to infrared light and back again.

The startup says that in 2028 it plans to launch a satellite into low Earth orbit — well below the 36,000 kilometers (22,000 miles) at which it eventually plans to operate. If all goes as planned, it will begin sending megawatts worth of power from geosynchronous orbit in 2030.

If that sounds bold, it is. The Overview doesn’t just tackle some promising but potentially intractable physics problems, it will also contend with grid-scale batteries, which are getting cheaper every year, and possibly nuclear fusion. But a number of people believe that it will happen that specialist suppliers have started to appear. A science fiction future, indeed.