Solar Power from Space? Caltech’s $100 Million Gambit - IEEE Spectrum

^{( August 11, 2021; IEEE Spectrum )}

Light weight, independent and modular components act in tandem to collect solar power and beam it to the ground using "inherently safe" microwave transmission. The modules are designed so that this transmission can be accomplished with no moving parts. The team is hoping for its first launch in 2022 or 2023 and large scale power delivery is still "years away".

High Earth orbit is a great place for a solar farm—the sun never sets and clouds never form. But to generate a meaningful amount of electricity, most past designs were unrealistically, and unaffordably, massive. Engineers depicted giant truss structures, usually measured in kilometers or miles, to which photovoltaic panels or mirrors were attached, absorbing or concentrating sunlight to convert to direct current, then transmit it to the ground via laser or microwave beams. Hundreds of rocket launches might be needed to build a single installation. It was technology too big to succeed.

"What was really required to make this compelling was to have a paradigm shift in the technology," says Harry Atwater, the Howard Hughes Professor of Applied Physics and Materials Science at Caltech and a leader of the project. "Instead of weighing a kilogram per square meter, we're talking about systems we can make today in the range of 100 to 200 grams per square meter, and we have a roadmap for getting down to the range of 10 to 20 grams per square meter."

Read the rest from IEEE Spectrum: Solar Power from Space? Caltech’s $100 Million Gambit

CalTech's principle investigators are:

• Harry Atwater
• Ali Hajimiri
• Sergio Pellegrino

Here is a 2018 video with Pellegrino talking about their research. Pellegrino notes that the technology can capture 84% of the energy that is transmitted from space to the ground.