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

Overview Energy emerged from obscurity today with a plan to use the world’s solar panels as nighttime energy collectors launched from space.

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

Overview has raised $20 million so far, with a portion of that money going toward an airborne demonstration of the energy technology. A light aircraft transmits energy using a laser to a ground receiver at a distance of 5 kilometers (3 miles).

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 energy has gone from pure science fiction to something closer to reality.

There are still many hurdles to overcome: First, deploying solar panels here on Earth is still much cheaper than sending them into space. The ability to transmit energy wirelessly from orbit to the surface of our planet is still in its infancy.

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

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

To reduce costs, these ground receivers will likely have to be smaller, and thus the power packs will have to be more compact and powerful. Companies are developing ways to quickly cut off the beam to prevent collateral damage to birds and planes, but it’s still a cause for concern.

Repurposing solar farms in the public eye would alleviate some of these concerns, although they would still have to convince the public that energy beams coming from space are safe and will not stray off target. (Remember SimCity 2000?) The company will also have to make sure its laser system is highly effective; Otherwise the benefit of collecting sunlight in space would evaporate as the energy is converted into infrared light and back again.

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

If it sounds bold, it is. Not only will it face some promising, but potentially unforgiving, physics problems, but it will also fight grid-scale batteries, which are getting cheaper every year, and perhaps nuclear fusion. But enough people believe it will happen that niche suppliers are starting to emerge. A sci-fi future, indeed.