Space-based solar power is getting serious—can it solve Earth’s energy woes?

Late last month in Munich, engineers at the European aerospace firm Airbus showed off what might be the future of clean energy. They collected sunlight with solar panels, transformed it into microwaves, and beamed the energy across an aircraft hangar, where it was turned back to electricity that, among other things, lit up a model of a city. The demo delivered just 2 kilowatts over 36 meters, but it raised a serious question: Is it time to resurrect a scheme long derided as science fiction and launch giant satellites to collect solar energy in space? In a high orbit, liberated from clouds and nighttime, they could generate power 24 hours a day and beam it down to Earth.

Today, both space and solar power technology have changed beyond recognition. The efficiency of photovoltaic (PV) solar cells has increased 25% over the past decade, Jones says, while costs have plummeted. Microwave transmitters and receivers are a well-developed technology in the telecoms industry. Robots being developed to repair and refuel satellites in orbit could be turned to building giant solar arrays.