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

Overview Energy emerged from stealth today with a plan to use the world’s solar panels as nighttime collectors of power beamed down from space.

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

Overview has raised $20 million to date, and part of that money has gone toward an airborne demonstration of its power beaming technology. A light aircraft transmitted power using a laser to a ground receiver over a distance of 5 kilometers (3 miles).

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

As space launch costs have declined over the past decade or so, space-based power has gone from pure science fiction to something closer to reality. 

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

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

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

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

Overview’s reuse of solar farms would mitigate some of those concerns, though it would still have to convince the public that energy beams from space are safe and won’t stray off target. (Remember SimCity 2000?) The company will also have to ensure 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 intends to launch a satellite into low Earth orbit — far below the 36,000 kilometers (22,000 miles) at which it ultimately intends to operate. If all goes as planned, it’ll start sending megawatts’ worth of power from geosynchronous orbit in 2030.

If it sounds audacious, it is. Overview isn’t just confronting some promising but potentially unforgiving physics problems but will also be battling grid-scale batteries, which are getting cheaper every year, and potentially nuclear fusion. But enough people believe it will happen that specialty suppliers have started popping up. A sci-fi future, indeed.