Space-based solar is making strides
- September 1, 2023: Vol. 10, Number 8

Space-based solar is making strides

by Mike Consol

The California Institute of Technology — the same institution associated with the likes of Richard Feynman, Robert Oppenheimer and William Shockley — has big news for space-based power. Researchers at the university have reportedly beamed solar power from space to Earth — and they say it’s a first.

The experiment is a part of Caltech’s Space Solar Power Project, and the researchers conducted the power transfer experiment using microwave technology. The researchers say microwave transmitters successfully beamed solar power collected in space to a receiver on the rooftop of Gordon and Betty Moore Laboratory of Engineering building on Caltech’s campus in Pasadena.

The attraction to space-based solar is evident: Photovoltaic cells can generate more power without the interference of the atmosphere and, when in correct orbit above the Earth, can collect sunlight and solar energy nearly 24 hours a day, eliminating the timing issues that plague land-based renewable energy.

As the need for energy to power the world’s economies grows, space-based solar power collection and transmission could be a quantum leap forward as a renewable energy source operating 24 hours a day and capable of wirelessly beaming power to Earth. What’s more, space-based solar panels are capable of collecting far more energy than standard solar panels due to its proximity to the Sun.

“In the same way that the internet democratized access to information, we hope that wireless energy transfer democratizes access to energy,” Ali Hajimiri, co-director of the Space Solar Power Project, said in a press release. “No energy transmission infrastructure will be needed on the ground to receive this power. That means we can send energy to remote regions and areas devastated by war or natural disaster.”

The ability to wirelessly transmit solar power from space has huge implications for renewable energy, so much so that Japan plans to start using it by the mid-2030s. A Japanese research team is looking to pilot the technology in 2025 with a public-private partnership.

The breakthrough has been a long time in coming. Back in 1979, motivated by the oil crisis at the time, the U.S. Department of Energy studied the idea, only to conclude it was too expensive. That study estimated the cost of space-based solar energy collection and transmission to be $495 billion in today’s dollars, which was more than the $302 billion current-dollar cost of the entire Apollo moon program.

Since then, however, the required electronics and rockets have become far less expensive and more powerful. What’s more, today’s objective to move past fossil fuels in favor of renewable energy sources to quell climate change, has added urgency to the goal.

In August, Caltech received a $100 million gift from the Donald Bren Foundation in support of the institution’s Space Solar Power Project. Hajimiri was quoted in Forbes saying: “Above the Earth, there’s no day and night cycle and no clouds or weather or anything else that might obstruct the Sun’s rays, so a constant power source is available.”

The Pentagon, a major backer of the project, is not alone in this effort. Euro zone scientists are making strides in trying to turn space-based power stations into a reality. The European Space Agency has realized the potential of these efforts and is now looking to fund such a project.

The euro zone and Pentagon will also be competing with China, which announced two years ago that it’s planning to build the world’s first solar power station to be positioned in Earth’s orbit.


Mike Consol ( is senior editor of Real Assets Adviser. Follow him on Twitter (@mikeconsol) and LinkedIn ( to read his latest postings.


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