Overview Energy wants to beam energy from space to existing solar power plants

Overview Energy has emerged from stealth today with plans to use solar panels around the world as nighttime power harvesters sent from space.

The startup plans to collect sunlight using a large solar array in geostationary orbit (about 32,000 miles above Earth, where the satellite coincides with the planet’s rotation). It then uses an infrared laser to transmit that power to a utility-scale solar power plant on Earth, allowing it to send power to the power grid nearly 24 hours a day.

Overview has raised $20 million so far, some of which will be used for aerial demonstrations of its PowerBeam technology. The light aircraft used a laser to transmit power over a distance of 5 kilometers (3 miles) to a receiver on the ground.

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

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

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

Other companies are attempting the same feat. Aetherflux is also pursuing a laser-based approach. Companies such as Emrod and Orbital Composites/Virtus Solis are developing microwave-based power transfers that transmit energy wirelessly using a different part of the electromagnetic spectrum than Aetherflux and Overview.

Microwaves are less affected by clouds and moisture than infrared lasers, and cannot be transmitted on cloudy days because suspended water droplets will absorb much of the energy. However, microwave-based systems cannot reuse existing solar power facilities and must build their own ground stations.

To keep costs down, these ground receivers will likely be smaller, so the energy beam will need to be denser and more powerful. Companies are developing ways to quickly shut down beams to prevent collateral damage to birds and aircraft, but concerns remain.

Overview’s reuse of solar power plants would alleviate some of those concerns, but it would still need to convince the public that energy beams from space are safe and on target. (Remember SimCity 2000?) The company also needs to make sure its laser system is highly efficient. Otherwise, the benefit of collecting sunlight in space would evaporate as the energy would be converted to infrared light and back again.

The company says it intends to launch the satellite in 2028 into low Earth orbit, much lower than the 36,000 kilometers (22,000 miles) altitude it will eventually operate at. If all goes according to plan, it will begin transmitting megawatts of electricity from geostationary orbit in 2030.

That may sound bold, but it’s true. Not only does Overview face some promising but potentially unforgiving physical challenges, it will also contend with increasingly cheaper grid-scale batteries and potentially nuclear fusion. But many believe it will happen, as specialized suppliers are starting to emerge. The future of science fiction.