Caltech shows space‑based solar power is no fantasy

One year after launching their demonstration project into space, Caltech scientists say they’ve shown it’s possible to power the Earth with 24/7 solar energy.

The scientists say they met three key objectives with their Space Solar Power Demonstrator, which was carried aboard a Momentus Vigoride spacecraft in January 2023. They sent a small amount of energy from space to a Caltech rooftop, tested various types of solar cells, and demonstrated the capacity of a novel power station.

With the mission in space concluded, the engineers are now continuing their studies in the lab, as they assess what they’ve learned and accomplished.

The space test “gave us a unique opportunity to take solar cells directly from the lab at Caltech into orbit, accelerating the in-space testing that would normally have taken years to be done,” says team member and Caltech professor Harry Atwater. “This kind of approach has dramatically shortened the innovation-cycle time for space solar technology.”

The scientists’ decade-long research was supported with a $100 million gift from Irvine Company Chairman Donald Bren, who as a young man first read of the potential of space-based solar power in Popular Science magazine.

The potential of space-based solar power is enormous – promising energy unhindered by fluctuations in daylight or weather, and unencumbered by fossil fuel emissions that increase the risk of climate change.

Some experts say space solar power would be superior to fusion, which has received much more media attention and billions of dollars in U.S. government support.

“There’s nothing preventing large-scale space solar power from being deployed within five to eight years,” former NASA researcher John Mankins, author of “The Case for Space Solar Power,” told the Standard last year.