Capturing solar energy in space and then beaming it down to Earth could provide consistent electricity supplies in places that have never seen it before. Should the as-yet untested idea work and be scalable, it has applications in IoT-sensor deployments, wireless mobile network mast installs and remote edge data centers.
The radical idea is that super-efficient solar cells collect the sun’s power in space, convert it to radio waves, and then squirt the energy down to Earth, where it is converted into usable power. The defense industry, which is championing the concept, wants to use the satellite-based tech to provide remote power for forward-operating bases that currently require difficult and sometimes dangerous-to-obtain, escorted fuel deliveries to power electricity generators.
This replacement system could provide directed solar-produced energy at night or electricity in places without grid delivery. It could also eliminate the alternatives: expensive, wind-solutions and mechanical generators that require maintenance. Extreme northern regions (good spots for data centers because they’re cold, allowing for ambient cooling), could have, conceivably, for the first time, usable solar power in the predominantly dark winter.
“Developers envision a system that is a constellation of satellites with solar panels, about 10,000-square meters, or about the size of a football field or tennis court,” writes Scott Turner of the Albuquerque Journal. The Air Force Research Laboratory (AFRL), in Albuquerque, along with defense technology company Northrop Grumman have just announced that they plan to spend $100 million dollars developing the hardware, called the Space Solar Power Incremental Demonstrations and Research (SSPIDR) project.
Two kinds of solar-panel technology are in common use on land now. Photovoltaic solar panels work by converting energy from the sun into electricity. They don’t have moving parts, so are inexpensive to maintain, unlike turbines. Another kind of solar panel uses mirrors and lenses. They grab, and then concentrate sunlight, producing heat, which then operates steam turbines.
“This whole project is building toward wireless power transmission,” Maj. Tim Allen, a manager on the project, told Turner. It will “beam power down when and where we choose.” Precise power beams will automatically track the target that needs the power, too. “We can put them down in specific locations and keep them there,” he says.
A significant advantage to placing solar panels in space, as opposed to on land, is that spacecraft get near constant sunlight, explains Rachel Delaney, a systems engineer on the project. Weather also becomes a non-issue, she says. It lets us “capture solar energy in space and precisely beam it to where it is needed,” Col. Eric Felt, director of the Space Vehicles Directorate at AFRL says in a separate news release. That could be as remote as the satellite footprint allows; single satellites are limited in reach as they only see the part of the Earth that’s in perspective.
“I believe the commercial industry will be happy to mimic what we’re doing and start providing this power commercially and not just for the military,” Turner quotes Allen as saying.