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Are Orbiting Solar-Energy Plants on Their Way?

In May, scientists in Pasadena, California, got “a ping” of wirelessly transferred energy from a rocket that had been launched four months earlier, according to Bloomberg.

What’s going on: “Designed at the California Institute of Technology and launched on a SpaceX rocket in January, the experiment had transferred power wirelessly, shifted the direction of the beam with no moving parts and then aimed it at Earth.”

  • “It’s one of three Caltech experiments, packed onto a single satellite, now testing key components of a space-based solar system.”

How it works: Thanks to thin-film solar cells and carbon-fiber materials, the potential weight of space-based solar plants has been reduced drastically. Meanwhile, private firms have slashed the cost of getting the plants into orbit.

  • What’s more, “[c]onstruction wouldn’t require highly trained astronauts laboring in suits; plant components stowed for launch could unfold themselves in space.”
  • A 2020 space launch by the U.S. military of a device capable of converting solar energy into microwaves helped lay the foundation “for future orbiting power plants.”

Some caveats: There are obstacles to creating a network of space-based solar plants.

  • “To generate a meaningful amount of energy, the plants would have to be far larger than any objects humans have placed in orbit to date.”
  • “They could be damaged by micrometeorites or space junk, and they’d have to overcome the inherent loss of energy that transmitting power by microwave—the most likely method, because microwaves pierce clouds—entails.”
  • Then there’s the significant investment the network would require.

Why this could work: With a $100-million-plus donation from Caltech trustees Donald and Brigitte Bren, the school “decided the approach that space-based solar advocates had taken in the past wouldn’t work.”

  • Their alternative: “Instead of a massive solid structure in space, each of Caltech’s power plants would be a fleet of detached, kitelike solar arrays orbiting in formation. Each array would be launched folded up, then unfurl in orbit.”
  • “Together, they would make up a single plant that could be a kilometer wide but without any physical structure linking the arrays.”

What’s next: For now, the researchers are collecting data from their current experiments and planning two more: one that “will test how a small-scale version of an array unfolds, and [another that] will see how different photovoltaic materials perform unprotected in the harsh environment of space.”

Our view: “Continual development of new sources of energy is critical to meeting energy security and decarbonization goals,” said NAM Vice President of Domestic Policy Brandon Farris.

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