The final frontier: Solar energy from space

Pacific Gas & Electric is going to great lengths--all the way to space--in its quest for renewable energy.

The California utility on Monday said that it will seek approval from regulators to purchase 200 megawatts worth of solar energy delivered from stealth space solar power company Solaren over 15 years.

(Credit: Space Energy)

The idea of space-based solar power (SBSP) is to place a device in space that can convert solar energy into a usable form and have it transmitted wirelessly to Earth. Scientists have thought to capture solar energy from space for decades but has it has never been done commercially.

Solaren proposes placing solar panels on a satellite to generate electricity that is converted to radio frequency energy on-board and sent to a ground station in California. The receiver then converts the radio frequency energy to electricity and it is fed into the power grid.

The goal of the project is to provide electricity to PG&E by 2016, said Solaren CEO Gary Spirnak in a Q and A posted on PG&E's company blog.

"While a system of this scale and exact configuration has not been built, the underlying technology is very mature and is based on communications satellite technology. For over 45 years, satellites have collected solar energy in earth orbit via solar cells, and converted it to radio frequency energy for transmissions to earth receive stations. This is the same energy conversion process Solaren uses for its (space solar power) plant," he said.

PG&E, which has significant investments in different forms of renewable energy, said that there is no risk to the utility since it only pays for power produced.

The advantage of space solar power is that energy can be harnessed at all times, even at night or when it's cloudy. Solaren's contract calls for it to deliver baseload power, the electricity needed to meet customer demand.

In its posting, PG&E executives said that generating space solar power cost effectively is a major challenge, but the people at Solaren have a lot of experience in space and satellites. The field also can also draw on years of research.

Another company called Space Energy has been formed to also tap solar energy from space using a similar technique as Solaren.