Space-based solar power is one step closer to reality

In January 2023, Caltech scientists launched the first-ever test of a satellite that can collect solar power in space and then beam it down to Earth. Now, one year later, the scientists announced their experiment was a resounding success.

How it works… The Caltech team’s satellite is equipped with a sail-like structure that captures sunlight in Earth’s orbit, then converts it into electricity. A custom-built transmitter onboard the satellite turns the electricity into electromagnetic energy, beaming it down to Earth via microwaves.

The potential advantages of space-based solar power are simple. It allows for a higher collection of the Sun’s energy due to lack of atmosphere, as well the potential for 24-hour solar power. But, much like your coworker’s billion-dollar app idea, there are still a few obstacles to overcome before widespread adoption.

Scientists experimenting with microwave technology across long distances have only been able to transmit enough energy to power a handful of LED light bulbs thus far.

• Using current technology, beaming several gigawatts of solar energy (or enough to power 1-2 million homes) would require a transmitter measuring roughly 1.2 miles in diameter – both on Earth and in space (for context, the ISS measures 361 feet by 243 feet).

⚡ Zoom out: Nearly all of the top global superpowers are currently funding space-based solar power projects, including the US, UK, EU, China, Russia, India, and Japan.