Pacific Gas & Electric Co. (PG&E) revealed that it has signed a power purchase agreement with California-based startup Solaren Corp., to buy up to 200MW of solar space energy, according to PG&E’s blog, "NEXT100." The solar power will be captured on satellite solar panels hovering in earth’s orbit and transmitted via radio frequency.
Solaren was formed in 2001 by a team of satellite engineers and space scientists to build a space energy company to generate and distribute electricity at competitive prices from Space Solar Power (SSP) stations in geosynchronous orbit. Solaren currently consists of about ten engineers and scientists, but plans to grow to more than 100 over the next twelve months.
Solaren states that the impetus for forming was the convergence of improved high efficiency energy conversion devices, heavy launch vehicle developments, and what it describes as a revolutionary Solaren-patented SSP plant design that is a significant departure from past efforts and makes SSP not only technically, but economically viable. The company claims that this will be the world’s first SSP plant. While a system of this scale and exact configuration has not been built, the underlying technology is said to be 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 (RF) energy for transmissions to earth receive stations. This is said to be the same energy conversion process Solaren uses for its SSP plant.
Solaren’s patented SSP plant design uses satellites in Earth orbit to collect solar energy in space and generate power, which is transmitted to the ground receive station for conversion to electricity for delivery to PG&E. Specifically Solaren’s SSP satellites use solar cells in space to convert the sun’s energy to electricity. This electricity powers high efficiency generator devices, known as solid state power amplifiers (SSPA). The SSPA devices on-board the satellite convert electricity into RF energy. Next the SSP satellite, using the RF energy and the satellite’s antenna, directs and transmits the RF power to the California ground receive station. The ground receiver directly converts the RF energy to electricity, and uses the local power grid for transmission to the PG&E delivery point.
Solaren states that it is currently supporting the CPUC regulatory filing process, and plans to provide additional details about the SSP pilot plant project in early Summer 2009.