It’s straight out of a Bond villain’s fantasy: an orbiting satellite outfitted with solar panels converts the sun’s energy into a microwave or laser beam that sizzles through thousands of miles of space and strikes a ground target. But instead of wreaking destruction to promote the goals of an evil genius, this energy is converted into electricity to power thousands of homes.
Clean, efficient and available 24-7, space-based solar power is the Holy Grail of renewable energy to a dedicated cadre of scientists. By 2035, the oil giant ExxonMobil estimates the world will demand 35 percent more energy per year than it did in 2005. This energy will need to come from power sources other than the carbon-intensive fuels that have powered societies since the industrial revolution.
Space solar proponents claim that our current renewable technologies can’t be scaled up fast enough to meet the anticipated demand. As such, space is the answer.
“The truth is we don’t have anything else,” said Marty Hoffert, an emeritus professor of physics at New York University. “We need to go through a revolutionary transformation away from fossil fuels.”
Here’s the theory behind it: The sun is roughly seven times more intense in space than on the Earth’s surface and shines constantly, which eliminates the problems of cloud cover, precipitation and. A satellite roughly 36,000 km (about 22,000 miles) above the earth can collect the sun’s energy using a large solar array and then send a beam to a “rectenna,” or ground-based antenna. The energy would then be converted into electricity.
The costs of launching equipment into space, coupled with the need for breakthroughs in energy conversion mean that space-based solar is still confined to the realm of science fiction. But several international space agencies have active space-based solar program as does California utility Pacific Gas & Electric. All are hoping to win the newest space race.
Will it remain the pet project of space agencies and buccaneering entrepreneurs or will the coming years bring a breakthrough? Find out more on Txchnologist, a new online magazine presented by GE. Every week, it offers an optimistic, but not utopian, take on humanity’s ability to tackle the great challenges of our era through industry, technology and ingenuity.
The first issue looks at the future of solar power, and features the full version of this story — which we’ve excerpted here on GE Reports — on the long struggle to get space-based solar power programs off the ground.
An orbiting solar array beams power via laser in this rendering by JAXA, the Japanese space agency. A JAXA representative said researchers are currently working on parallel programs to use both ground-based microwaves and, separately, lasers to transmit 1 kilowatt of power within the next four years. They hope to have a demonstration program in orbit within eight years.
