energyDigger writes about the possibility of solar energy facilities in space orbiting Earth.

Orbiting power plants capable of collecting solar energy and beaming it to Earth appear “technically feasible” within a decade or two based on technologies now in the laboratory, a study group of the Paris-headquartered International Academy of Astronautics said.

Such a project may be able to achieve economic viability in 30 years or less, it said, without laying out a road map or proposing a specific architecture. 

The solar energy would be collected 24 hours a day in space and delivered to locations on Earth via wireless power transmission. Since the Sun is always shining on Earth, the satellites could double the amount of power from Earth-based solar facilities.

The idea is to put first one, then a few, and later scores of solar-powered satellites in geosynchronous orbit over the equator. Each as wide as several kilometers across (one kilometer equals 0.6 miles), the spacecraft would collect sunlight up to 24 hours a day, compared with half that, at most, for surface panels now used to turn sunlight into electricity.

The power would be converted to electricity on-board and sent to wherever it is needed on Earth by a large microwave-transmitting antenna or by lasers, then fed into a power grid.

However, the idea would have to be funded by governments as the authors of the study believe there is too much risk and uncertainty to entice private investors.  The authors also did not look at the cost of implementing such a project which could run into the tens of billions of dollars or euros.

Skeptics view the concept as a non-starter, at least until the cost of putting a commercial power plant into orbit drops by a factor of 10 or more. Other hurdles include space debris, a lack of reliable market studies and the high development costs.

Australian retired aeronautical engineer Ian Bryce, says there are better alternatives. “Much as I am a fan of space, and would love to see a large new space initiative, I see problems with space solar power,” he says.

Bryce says even if the technology was fully funded from tomorrow, it would take too long to deliver power. “A much more feasible way to generate electricity sustainably is solar thermal with storage. This technology is here now, and plants can be ordered. At least 30 years closer than space solar power.”

The study was led by John Mankins, a 25-year NASA veteran and the U.S. space agency’s former head of concepts. His company has been awarded a NASA contract to pursue space-based solar power options.


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