Wireless energy: Race to decarbonise turns to space
Hajimiri envisages thousands of solar panels floating in space,unhindered by day-night cycles, wirelessly transmitting massive amounts of energy to receivers on Earth.
• NELL GALLOGLY
NEW YORK: Ali Hajimiri thinks there’s a better way to power the planet — one that’s not getting the attention it deserves. The Caltech professor of electrical engineering envisages thousands of solar panels floating in space, unobstructed by clouds and unhindered by day-night cycles, wirelessly transmitting massive amounts of energy to receivers on Earth.
This year, that vision moved closer to reality when Hajimiri, together with a team of Caltech researchers, proved that wireless power transfer in space was possible: Solar panels they had attached to a Caltech prototype in space successfully converted electricity into microwaves and beamed those microwaves to receivers about a foot away, lighting up two LEDs.
The prototype also beamed a tiny but detectable amount of energy to a receiver on top of their lab’s building in Pasadena, Calif. The demonstration marks a first step in the wireless transfer of usable power from space to Earth — a power source that Hajimiri believes will be safer than direct sun rays. “The beam intensity is to be kept less than solar intensity on earth,” he said.
Finding alternative energy sources is one of the topics that will be discussed by leaders in business, science and public policy during The New York Times Climate Forward event. The Caltech demonstration was a significant moment in the quest to realize space-based solar power — a clean energy technology that has long been overshadowed by other long-shot clean energy ideas, such as nuclear fusion and low-cost clean hydrogen.
If space-based solar can be made to work on a commercial scale, said Nikolai Joseph, a NASA Goddard Space Flight Center senior technology analyst, such stations could contribute as much as 10 percent of global power by 2050. The idea of space-based solar energy has been around since at least 1941, when the science-fiction writer Isaac Asimov set one of his short stories, “Reason,” on a solar station that beamed energy by microwaves to Earth and other planets.
In the 1970s, when a fivefold increase in oil prices sparked interest in alternative energy, NASA and the Department of Energy conducted the first significant study on the topic. In 1995, under the direction of the physicist John C. Mankins, NASA took another look and concluded that investments in space-launch technology were needed to lower the cost before space-based solar power could be realized.
“There was never any doubt about it being technically feasible,” said Mankins, now president of Artemis Innovation Management Solutions, a technology consulting group. “The cost was too prohibitive.” The advent of Elon Musk’s SpaceX has brought a steep decline in the cost of rocket launches. From 1970 to 2000, the average low-earth-orbit rocket launch cost was around $18,500 for a kilogram, or 2.2 pounds, of weight; today, the cost has plummeted to as low as $1,500 a kilogram. That reduction has helped drastically reduce estimates for building power stations beyond Earth’s atmosphere.
A 1980 review by NASA concluded that the first gigawatt of space-based solar power (enough energy to power 100 million LED bulbs) would cost more than $20 billion ($100 billion today). By 1997, NASA estimated that number had dropped to about $7 billion ($15 billion today); now, it is estimated to be closer to $5 billion, according to a study conducted for the European Space Agency in 2022.
“I used to be a critic of space-based solar power,” said Ramez Naam, a climate and clean energy investor. Naam is now actively seeking space-based solar companies to invest in. “The dramatically changing cost of space launches has changed everything,” he said.