|
|
|
|
|
|
|
|
|
|
|
|
|
 |
GreenVolts breaks ground on America's largest HCPV power plant
August, 2008: GreenVolts Inc., a San Francisco-based developer of high-concentration PV systems, this summer broke ground on what would be the largest solar power plant in the US – and one of the largest in the world – to use optics to concentrate sunlight hundreds of times onto tiny solar cells.
|
 |
|
© GreenVolts, Inc.
|
|
|
Breaking ground: GreenVolts plans to complete the first 1 MW phase of a nearly 3 MW concentrating PV plant later this year, using its 3 kW carousel trackers.
|
|
»We have indeed started construction on the first phase of the project,« GreenVolts CEO Bob Cart told PHOTON International. Located in Byron, California, about 63 miles directly east of San Francisco, Cart expects this first 1 MW phase to begin delivering electricity later this year to Pacific Gas & Electric Company (PG&E). The utility – required under state law to supply 20 percent of its electricity deliveries with renewable resources by 2010 – has signed a 20-year power purchase agreement with GreenVolts for the plant's output at unspecified pricing (see PI 8/2007, p. 81).
However, the levelized 20-year contract pricing is likely to be in the range of 10.5¢ to 15¢ per kWh. This estimate is based on the fact that the California Public Utilities Commission's (CPUC) approval of the contract stated that the project »exceeds the 2006 market price referent« (MPR) – in other words, the estimated price of power generated by a combined cycle natural gas plant in California. That price was set by the CPUC at 8.5¢ per kWh for plants coming on line in 2008. The CPUC does not disclose how much higher the price of the contract is, but PG&E's director of procurement last year told PHOTON International that it would only consider signing contracts for wholesale solar power at or near 10.5¢ per kWh, or about 20 percent higher than the MPR (see PI 9/2007, p. 110). Other solar players bidding on California utility projects, such as First Solar Inc. (see article, p. 84), report that bids are in the 12¢ to 15¢ per kWh range.
According to Cart, the facility's generating capacity »will be closer to 3 MW« when completed in the fourth quarter of 2009. When first approved by the CPUC in December, the plant's capacity was listed at 2 MW and output at 4.6 GWh per year. Currently, the largest concentrating PV plant in operation in the US is a 1 MW low-concentration system supplied by German company Solon AG for a project in Colorado. In Spain, Guascor Foton already produced 12 MW of a silicon cell-based high-concentration system in 2007, including at least two projects in the 3 MW range.
GreenVolts' first commercial-scale project represents the largest single project in the world using multi-junction solar cells – also known as III-V cells – to break ground so far. Several other companies have already built, or are in the process of building, III-V-based concentrators at Spanish research institute ISFOC, which are each in the hundreds of kilowatts (see PI 4/2007, p. 122). The GreenVolts facility will consist of hundreds of the company's low-profile 3 kW two-axis carousel trackers. These contain GreenVolts' high-concentration receivers that use a primary reflective mirror and a secondary refractive optical element to concentrate sunlight by 625 times onto the gallium arsenide-based triple-junction cells. While the cells are approximately 35-percent efficient, the company claims a module efficiency of 28.5 percent.
GreenVolts, which Cart founded in 2005, is assembling its systems on a pilot production line it built after securing a $10 million »Series A« round of venture capital last October. A second round is expected to be announced soon.
|
back
|
|
|
|
|
 |
|
|
|
|