Harvesting Solar Power in Space

Space-based solar power (SBSP) is the concept of collecting solar energy during a space orbit and beaming it safely to a fixed point on Earth. Recently, the British government sponsored an SBSP competition to award more than $5.5 million in grants to the most promising innovators of this novel technology, which may be the key to producing cost-effective, cleaner, more renewable energy. The goal is an array of spacecraft to collect sunlight and convert it into microwaves before beaming them to a receiver on Earth, where it is converted into electricity.

Because space has no atmosphere, the sunlight is undiluted, which means that a space-based solar panel would be able to generate more energy than a comparable panel on Earth. The other potential benefit to collecting solar power in space is that there are no day-night cycles, cloud cover or seasonal variations to contend with.

Among the grant winners were two British schools: Cambridge University, which is developing ultralightweight panels that can withstand high radiation levels, and Queen Mary University, which is working on a wireless system to safely beam the energy to Earth. In related research, scientists at the California Institute of Technology were able to successfully transmit power wirelessly in space and to beam detectable power to Earth using an experimental spacecraft.