Astrium Hopes To Test Grabbing Solar Energy From Orbit

goldaryn writes "Word from the BBC today is that Europe's biggest space company is seeking partners to help get a satellite-based solar power trial into orbit: 'EADS Astrium says the satellite system would collect the Sun's energy and transmit it to Earth via an infrared laser, to provide electricity. Space solar power has been talked about for more than 30 years as an attractive concept because it would be 'clean, inexhaustible, and available 24 hours a day.' However, there have always been question marks over its cost, efficiency and safety. But Astrium believes the technology is close to proving its maturity.'"

Comments

Re:I don't see how this can be efficient ...

[Salgak1]

Actually, the efficiency comes if you build in-orbit from indigenous materials. The classic powersat concept generally involves lunar regolith mining, launch to low Lunar orbit via magnetic mass-driver, and solar smelting in orbit.

The first one, and associated infrastructure, costs a fortune. However, after that, your only costs are ongoing personnel costs, O&M., and the cost of new ground stations. Because the powersat-production infrastructure remains intact in orbit.

Additionally, you don't have to use silicon or other semi-conductor photocells for power: you could set up mirror arrays to concentrate sunlight on a working fluid, to heat it, and run the resulting heated gas through turbines for power generation. Obviously, you'd need a closed-loop system for that, but with large mirror arrays, behind each would be an area completely out of sunlight, and ideal for heat sinks for cooling the gases back to fluid for re-use in the cycle. . .

The economics of payback are actually not that bad: ~20 years for capital payback, and all profit from that point on. . .