TECHNOLOGY FOR CHANGE

Solar Energy Satellites No Longer Science Fiction

Dave Greenfield | Date: 12-22-09 | Comments

Both the state of California and Japan are looking to outer space for power, via solar energy satellites that would send energy back to Earth.

In 1968, Peter Glaser suggested that solar collectors be placed in orbit to transmit power back to Earth. What must have seemed like science fiction in the sixties may well start to become reality in 2010.

California�s Public Utility Commission voted in April to approve an agreement with Pacific Gas & Electric and Solaren Space that would allow an orbiting solar power collection to power California. These solar energy satellites would work much like any other transmission satellite, except instead of sending information to Earth, they would be send energy. The proposed plan would add 200 megawatts to the state�s power grid.

Solaren Space and PG&E aren't alone in the pursuit of space power. Japanese firms have been working on the concept as well, announcing in September plans to build a 1-gigawatt solar power collector. If it comes to fruition, enough energy would be transmitted to Earth to power hundreds of thousands of homes. A 2030 completion date and a $20 billion price tag are anticipated. How would this work?

Satellites have photovoltaic panels that can harness the sun�s energy 24 hours a day with no atmospheric interference. These are similar to the panels that some people and businesses have on their rooftops. In the plan proposed by Solaren, a cluster of four satellites would use concentrated photovoltaic cells to absorb energy from the sun. This energy would be converted into electricity and then into microwaves. The microwaves would then be beamed to Earth, where they would be converted back into electricity for use in the grid.

The technology wouldn�t affect birds, planes or people in the areas where the microwaves were collected. In essence, it is very similar to how satellite television is transmitted. The difference is that the vast amount of energy collected is transferred into energy.

While the technology is tremendously exciting, it remains to be seen whether this method will provide large amounts of power�or enough to become a real alternative to oil. The world will wait for that answer until 2030.