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8 years ago another billionaire ploughed millions into space to harvest solar power and beam it back down to Earth

Caltech received $100m for the project and is only just telling us now

Billionaire Donald Bren was behind a quiet $100m donation in 2013 that established Caltech's Space-based Solar Power Project (SSPP) in an attempt to harness solar power from outer space, the California private research university revealed this week.

The real estate magnate was inspired by a 2011 article in Popular Science (perhaps this one?). He also knew a thing or two concerning power distribution problems from his experience master planning cities like Irvine, California.

Bren subsequently approached Caltech to discuss his ideas. Caltech said he has no stake in the tech and won't make any money from it. The donation is being disclosed now, eight years later, as SSPP wants to highlight upcoming project milestones.

In early 2023, the org is launching technology demonstrating prototypes that collect and convert sunlight to electrical energy, transferring the energy wirelessly using RF and a deployable 6x6ft ultralight structure that integrates the power.

By integrating the solar power and RF conversion into one element, SSPP says the spacecraft avoids a power distribution network, mitigating localised failure and making the structure scalable.

The SSPP website describes the benefit of using solar power harnessed in outer space, which essentially boils down to a lack of shade and night-time hours that we Earthlings are forced to endure:

Collecting solar power in space and transmitting the energy wirelessly to Earth through microwaves enables terrestrial power availability unaffected by weather or time of day. Solar power could be continuously available anywhere on earth.

Previous prototypes were launched in 2017. In May, a prototype with 1.5kg/m2 areal density collected solar power and transmitted it to Caltech. Seven months later, photovoltaics and power transfer circuitry were added to the even lighter design (1 kg/m2 areal density) and beam steering was incorporated.

The idea of space solar panel tech has been around a while but its measurable potential is continually improving. In 1941, science-fiction writer Isaac Asimov described space stations transmitting solar energy via microwave beams in his short story Reason. In the early 1970s, Peter Glaser got a patent for a design to transmit power from satellite to ground using microwaves.

In the late '70s, NASA explored the concept with the US Department of Energy and revisited it in 1999 through the Space Solar Power Exploratory Research and Technology program (SERT). A year prior, in 1998, Japan's space agency (JAXA) began developing a space solar power system. That programme still runs today.

More recently, the US Naval Research Laboratory conducted its first test of solar power generation in a satellite in May 2020 to gauge process efficiency. The research laboratory's PRAM-FX harvests and converts solar energy using a 12-inch square tile surface.

Should the Bren-funded SSPP continue to succeed with its technology demonstrations and tests, it may be another six years before the world sees it applied for usable applications from what is hopefully affordable, renewable clean energy. ®

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