Solar energy collected in space could solve energy problems

Giant structures consisting of rows of photovoltaic cells orbiting the Earth, or on the Moon, would not be affected by cloud cover, atmospheric dust or by the planet’s cycle of day and night, and would receive an average of eight times as much sunlight as on the Earth’s surface, according to NASA. Collected energy would then be transmitted as microwave radiation to Earth, where it would be captured by an antenna located in an isolated area – due to the dangers associated with microwaves – and transformed into usable electricity. The technology, says NASA, could be up and running in 20 years time.

“We now have the technology to convert the sun’s energy at the rate of 42 to 56%,” said Dr Neville Marzwell, technical manager of the Advanced Concepts and Technology Innovations programme at NASA’s JET propulsion Laboratory. “We have made tremendous progress.”

One of the main problems of the technology is the expense of the arrays of photovoltaic cells. However, costs can be cut by reducing the area of the arrays. “If you can concentrate the sun’s rays through the use of large mirrors or lenses you get more for your money because most of the cost is in the PV arrays,” said Marzwell.