California utility PG&E today announced deals with San Francisco solar startups GreenVolts and Cleantech America to build photovoltaic solar power plants. The projects are relatively small-scale – 2 megawatts for GreenVolts and 5-megawatts for Cleantech America – but represent a move by a major utility to use solar power stations close to urban areas to supply green energy during peak demand. To date, utilities like Southern California Edison (EIX) and San Diego Gas & Electric (SRE) have tended to contract for massive megawatt solar thermal power plants to be constructed in the Mojave Desert far from the cities they will supply. That often means billion-dollar transmission lines must be built or upgraded.
GreenVolts, which was featured in Green Wombat’s Big Solar story in the June issue of Business 2.0, will build its power plant on just eight acres in Tracy, a farm town turned exurb about 60 miles east of San Francisco. The company has developed a high concentration photovoltaic technology that features microdishes that track the sun and focus its rays on small but highly efficient solar cells. Rotating platforms hold 176 of the dishes (image above). The Tracy plant goes online in 2009. Earlier this month, GreenVolts announced a deal to build a prototype power plant for Avista (AVA), a Spokane, Washington-based utility.
The second deal is for a 5-megawatt plant to be built by Cleantech America on 40 acres near a PG&E (PCG) substation in the Central Valley city of Fresno. The power plant is set to begin operating in 2009. The company has apparently been operating under the radar – or at least Green Wombat’s radar, despite the fact that its offices are located across California Street from Business 2.0. Hello! Cleantech America’s site is sketchy on the details of it technology, describing a mix of "current and new concentrator PV solar technologies." Green Wombat is crashing on a magazine deadline today but will report further on the company in the coming week. CEO Bill Barnes certainly has an interesting resume: according to the Cleantech America site, he’s a former Time magazine editor who co-founded children’s clothing company Gymboree and "has participated in the start-up of successful companies in the energy and technology industry."
Green Wombat 
RE: “That often means billion-dollar transmission lines must be built or upgraded”.
WRONG ! WRONG ! WRONG ! Even 1,000MWe in the aggregate of solar thermal electric power plants in the Mojave Desert, Southern California will not need more that 28 miles of transmission lines at cost of $1.44 million per mile, whereas only $40 million
Such proposed plants are located within CAISO major existing grids along Hwy 395 and Hwy 58, known as Kramer Cluster 7 CAISO Zone SP-15, and are not really congested, i.e., can accommodate more than 1,000MWe, not limited to that at the Kramer-Lugo Substations, upgrades cost cannot be not more than $10 million unless there are bus and transformers made from gold.
We should note that this is a big bad utility that is pushing this endeavor. Remember, PG&E is the same utility from Eric Brochovich. This is a good sign that the solar industry is getting some legs behind it and that there can be a sustainable option for our utilities in the future.
The cost of San Diego Gas & Electric’s proposed Sunrise Powerlink transmission project – which would be used in part to transmit electricity from the Stirling Energy Systems solar power plant – is $1.256 billion.
http://www.cpuc.ca.gov/static/hottopics/1energy/a0512014.htm
Exhibit “A”
Public Disclosure by Southern California Edison Company (SCE). Link to SCE:
http://www.sce.com/_Search?advancedSearch=&recPerPage=10&as_q=&q1=transmission+lines+costs&btnSiteSearchTop=GO
SCE CONCEPTUAL TRANSMISSION REQUIREMENTS AND COSTS FOR INTEGRATING RENEWABLE RESOURCES
(Aggregate of 128 miles of transmission facilities & substations = $180 millions Identical costs for trunk lines to Renewables)
Facilities for Cluster 7 (Kramer Area) SCE has received identification of a total of 1,005 MW of conceptual renewable generation resources located in the Kramer area. Network facilities necessary for interconnecting and delivering output from the renewable resources located in Cluster 7 are identified in the following two-level approach. Renewable generation development in other north of Lugo clusters will result in different transmission requirements. The identification of facilities necessary for simultaneous development is covered in the section titled Simultaneous Development of Renewable Resources in Multiple North of Lugo Clusters.
Cluster 7 Level 2: Up to 1,005 MW The Level 2 upgrades reflect the transmission facilities necessary to interconnect up to 1,005 MW of renewable generation at Kramer. The necessary transmission upgrades include: Construction of a new 48 mile 500 kV transmission line initially energized at 230 kV from Lugo to Kramer. Kramer 230-kV and Lugo 230-kV switch rack expansion to accommodate new transmission line. New 75 mile Mira Loma-Vincent 500 kV transmission line (no bid adder). Third Lugo 50/230 kV Transformer Bank Modification to Kramer Special Protection Scheme (SPS). Cost estimate for these facilities is estimated to be approximately $180 million. This cost results in an estimated bid adder of 1.14 cents based on a total of 700 MW of solar generation with a capacity factor of twenty-five percent, 275 MW of wind generation with a capacity factor of thirty-two percent, and 30 MW of biomass with a capacity factor of ninety percent.
Exhibit “B”
Current cost for transmission lines approx. 45% more than 1995 costs http://www.eia.doe.gov/cneaf/pubs_html/feat_trans_capacity/table2.html
Exhibit “C”
It costs about $1.5 million per mile for transmission lines, according to statistics from Acciona Solar Power, which owns solar thermal plants. http://news.zdnet.com/2100-9596_22-6182947.html
Large Scale Solar Power Projects
Green Wombat has a couple of cool articles up concerning large-scale solar power projects. The first concerns a 500 MW plant being built in New Mexico with cooperation between San Diego Gas and Electric and Southern California Edison, among others. The…