California OKs 4,142.5 MW since August Of Concentrating Solar Power

Continuing a trend that has characterized the second half of 2010, the California Energy Commission approved two more utility-scale concentrated solar energy plants, totaling 650 megawatts (MW).

The newly approved plants use solar-thermal technology, generating electricity by converting solar radiation into heat energy that then creates steam that powers a turbine.

Both plants are in the desert of eastern Riverside County, and because they impinge on federal lands must still get sign-off from the U.S. Department of the Interior before construction can begin. That, however, might be a foregone conclusion.

While the California commission has been on a solar roll lately, licensing nine concentrated solar energy plants totaling 4,142.5 MW since August, U.S. Secretary of the Interior Ken Salazar has been keeping up, approving eight concentrating solar power plants since early October. The commission said it expects the necessary federal approvals for the two projects licensed this week in early 2011.

Solar Millennium is behind the Palen Solar Power Project, a 500-MW concentrating solar power project proposed for a spot halfway between Indio and Blythe. Palen, as planned, will actually consist of two 250-MW plants using the company’s parabolic trough system.

The Rice Solar Thermal Project, meanwhile, is set for private land 30 miles northwest of Blythe. Developer SolarReserve said it plans to use what’s known as a tower system, in which a large field of tracking mirrors focus the sun’s thermal energy on a central tower. The system also uses molten salt to retain the heat captured during the day in order to continue producing energy well after sunset if needed, the company said.

Part of the motivation of California around this seems to be that state’s Renewables Portfolio Standard, which requires its electricity utility companies to use renewable energy to produce 20 percent of their power by 2010 and 33 percent by 2020. California is also trying to make itself into the preeminent clean energy hub in the nation even as Congress falters on pushing through significant renewable power legislation. What will California’s leading by example in this area garner it? To find out, we turned to Dave Cavanaugh, a senior analyst on the topic with cleantech market research firm Pike Research for some answers.

EarthTechling (ET): California is in a wave of approving solar thermal plants right now. Can you give a brief explanation of what exactly solar thermal technology is.

Dave Cavanaugh: Fundamentally, solar thermal in this context should be thought of as large, utility-scale concentrated solar thermal (CST) to distinguish it from small rooftop water heating systems that are also often called solar thermal. Basically, CST systems concentrate solar radiation, heat a fluid with the concentrated radiation, generate steam with the heat, and generate electrical power using a steam turbine. Several types of CST systems are gaining traction, but the two most common types involve: 1) long strings of parabolic trough mirrors that focus radiation on a tube in the center of the trough and 2) a huge circular array of mirrors that focus solar radiation and heat on a high central tower (a so-called “power tower”).

ET: What is the motivation behind California trying to approve these nine projects before year’s end?

Cavanaugh: California is trying to approve projects before the end of 2010 because certain US federal incentives are set to expire this year and because the state has a lofty goal of producing 20% of its power consumption from renewable sources by the end of 2010. The nine projects all total will have potential to produce over 4,300 MW of solar energy for the state’s power grid.

ET: What kind of impact will that have on California’s energy needs?

Cavanaugh: While these CST projects have the potential for generating a lot of power and would supply a significant part of California’s total power needs, we suggest that CST projects must demonstrate actual reduced power cost generation capability promised for large-scale CST plants (not demonstrations projects) in order for the state to actually enjoy a significant impact on their power needs. As importantly, constructing large CST plants and connecting them to the grid from remote locations like the California deserts may prove a daunting task and add significant cost to power delivered to major cities.

ET: Is California rushing too fast into solar energy through this process? Why or why not?

Cavanaugh: We applaud California’s push to generate 20% of power requirements by the end of 2010 and its proposal to require 33% of power generation from renewable by 2020. Implementing solar power generation at this rate is acceptable from the viewpoint of setting targets for utilities. Though meeting the 20%/2010 goal may be difficult, providing 33% of CA’s power requirements by 2020 will likely be very doable. The sticking point lies with the utilities’ ability to implement power generation from new projects on time and without substantially raising the cost of power to consumers. Currently, we believe that solar PV provides a more reliable, proven, and cost effective way to reach RPS goals.

ET: Will this aggressive push into solar impact other types of renewable energy development?

Cavanaugh: With the enormous reduction in the cost of solar PV modules in 2009 and the ability to install PV on commercial and residential rooftops, we believe that proven and more bankable PV technology has already reached grid parity in much of California and will present CST with a formidable barrier to entry in 2010 and even more so in 2011.

Back in June 2009, U.S. Department of the Interior Secretary Ken Salazar vowed to have 13 utility-scale solar projects on federal lands approved and ready for construction by the end of 2010. After a slow start, it’s beginning to look like he might make it.

Salazar just green-lighted the eighth such project — all since early October — consisting of two 250-megawatt (MW) concentrated-solar plants 80 miles northwest of Las Vegas in Nye County, Nevada. The Amargosa Farm Solar Project by developer Solar Millennium will use parabolic-shaped mirrors that focus solar energy to generate steam and turn electricity-producing turbines.

With its thermal storage capacity, Amargosa will have the ability to continue to feed power to the grid even at night. However, because of its heavy water needs, there was concern about the project’s potential impacts on the nearby Ash Meadows National Wildlife Refuge and Devils Hole. The Interior Department’s press release said it “worked closely with Solar Millennium to develop an innovative water mitigation plan that can serve as a model for future solar projects.”

The Interior Department said Salazar’s flurry of approvals this fall will lead to the construction of plants that will generate a total of more than 3,500 MW, enough electricity to power at least 1 million homes and perhaps up to 2.4 million. Construction on the plants will generate 6,000 jobs in the near term, and ultimately more than 700 permanent plant operations jobs.

As with all of these utility-scale projects, a key to making it happen was the availability of tax credits through the American Recovery and Reinvestment Act, in this case totaling around $1 billion for Germany-based Solar Millennium.

by Pete Danko and Nino Marchetti,