Houston

AS we face $4.50 a gallon gas, we also know that alternative energy sources  coal, oil shale, ethanol, wind and ground-based solar  are either of limited potential, very expensive, require huge energy storage systems or harm the environment. There is, however, one potential future energy source that is environmentally friendly, has essentially unlimited potential and can be cost competitive with any renewable source: space solar power.

Science fiction? Actually, no  the technology already exists. A space solar power system would involve building large solar energy collectors in orbit around the Earth. These panels would collect far more energy than land-based units, which are hampered by weather, low angles of the sun in northern climes and, of course, the darkness of night.

Once collected, the solar energy would be safely beamed to Earth via wireless radio transmission, where it would be received by antennas near cities and other places where large amounts of power are used. The received energy would then be converted to electric power for distribution over the existing grid. Government scientists have projected that the cost of electric power generation from such a system could be as low as 8 to 10 cents per kilowatt-hour, which is within the range of what consumers pay now.

Image Credit... Paul Davis

In terms of cost effectiveness, the two stumbling blocks for space solar power have been the expense of launching the collectors and the efficiency of their solar cells. Fortunately, the recent development of thinner, lighter and much higher efficiency solar cells promises to make sending them into space less expensive and return of energy much greater.