The U.S. Naval Research Laboratory is working on technology to capture solar power in space, then beam it down to Earth.
Solar panels on Earth are limited by our day/night cycle and cloud cover - solar panels in space can soak up power constantly. The U.S. Naval Research Laboratory (NRL) is working on technology to harness enough energy from orbiting solar panels to power military bases or even cities.
Dr. Paul Jaffe, a spacecraft engineer at NRL, has built and tested a module to capture and transmit solar power from space, which can make it easier to power remote bases and would provide cost-competitive power.
"Launching mass into space is very expensive," says Jaffe, but he has built two different prototypes of a "sandwich" module that is four times more efficient than anything previously constructed. Both designs of the "sandwich" module include a photovoltaic panel on one side to receive solar energy, an antenna on the other side to beam power to Earth, and electronics in between that convert the energy to a radiofrequency suitable for beaming.
"People might not associate radio waves with carrying energy," says Jaffe, "because they think of them for communications, like radio, TV, or cell phones. They don't think about them as carrying usable amounts of power."
To mitigate any potential concerns about orbital death lasers, Jaffe explains that the antenna only sends energy to a specific receiver that asks for it. Further, by using microwaves instead of lasers, the power is less concentrated.
"The most sobering thing about all of this is scale," says Jaffe. He imagines an array of modules that would span ten American football fields; compare that to the largest man-made satellite, the International Space Station, which is barely longer than one.