The Pentagon has successfully tested a solar panel in low-earth orbit as a prototype of potential future power-generating systems capturing light from the Sun and beaming it back as energy to earth.
In May 2020, engineers at the U.S. Naval Research Laboratory launched the Photovoltaic Radio-frequency Antenna Module (PRAM) aboard an Air Force X-37B Orbital Test Vehicle, as part of a study into prospective terrestrial use of solar energy captured in space.
The tile module the size of a pizza box was designed to test the ability to harvest power from its solar panel and transform the energy to a radio frequency microwave, the U.S. Naval Research Laboratory said at the time.
The system is attached to a Pentagon unmanned drone looping the Earth every 90 minutes.
The panel’s position in orbit makes it more powerful in capturing the light of the Sun than solar systems capturing sunlight that reaches the surface of the earth, the developers of the project tell CNN.
“We’re getting a ton of extra sunlight in space just because of that,” Paul Jaffe, a co-developer of the solar panel in space project, told CNN.
According to the latest tests the scientists have analyzed, the solar panel in orbit can produce some 10 watts of energy, enough to power a tablet computer, Jaffe told CNN’s Nick Paton Walsh.
The solar panel has not sent power generated from the Sun to the Earth yet, but the advantage of such a system in space would be that the energy can be transmitted from space to any corner of the earth, where grids need it.
One of the biggest disadvantages of such systems is, unsurprisingly, cost.
Additional challenges that need to be resolved include regulatory concerns, including spectrum and safety, and potential international coordination, the team of scientists said when they published part of their findings in the January edition of IEEE Journal of Microwaves.
The first results of the tests with the solar panel in space have shown that “the experiment is working,” Jaffe told CNN.