December 19, 2007

Solar energy is getting a jumpstart. Energy suppliers scattered throughout the Southwest have asked bidders to submit proposals to build a 250 megawatt solar power project.

The consortium plans on picking a winner by June 2008 so that the project would be completed by 2012. It would be "concentrated solar power" that focuses sunlight, usually with mirrors, to heat a fluid to high temperatures to drive the engine -- something that proponents say can be used for large-scale solar power generation. That differs from the more traditional approach of photovoltaic solar power systems in which light interacts with sheets of semiconductors to generate electricity. That solar technology is more suitable for smaller projects.

The impetus behind the proposed solar site is state mandates that force utilities to offer a set percentage of their electric generation from renewable energy. Arizona's standard, for example, is 15 percent by 2025. The venture would cost $250 million to build, and cover 350 acres. Such renewable projects enjoy widespread support in the Southwest and regulators have baked into existing rates the cost of construction and production.

While concentrated solar power is less expensive than photovoltaic solar power, it is still at least twice the cost of generation powered by fossil fuels. Prices, though, will assuredly come down. The thinking is that the creation of more projects will precipitate that decline. And, if such technological progress is combined with federal legislation that puts a price on carbon emissions, solar manufacturers and producers would crank up.

In any event, a key obstacle is that conventional plants are base-load facilities that can operate all the time. Green energy plants are used as "peaking" facilities that run typically on the hottest days. "With intermittent renewables, we have to create the storage ourselves," says Michael Winkler, professor at the Schatz Energy Research Center at Humboldt State University.

But some smart people are working on that. Palo Alto-based Ausra, for example, uses concentrated solar power technologies to gather the sun's energy as heat. It is also developing storage systems. It says that its plants will gather energy during daylight hours to generate power as needed for up to 20 hours. By storing energy as heat during the day, a power plant can continue to produce electricity during dark or cloudy periods.

High Powered Backers

Ausra has some high-powered ventured capitalists backing it. The company has a pilot project going in Australia and talks happening here with Pacific Gas & Electric and Florida Power & Light. Together, they want to build a 1,000 megawatt solar power plant, although they would start with smaller demonstration facilities that could produce as little as 10 megawatts or as much as 175 megawatts.

To be sure, skeptics say that while the land space may exist to construct solar farms, the technology is still expensive and unreliable. Solar costs 16-25 cents a kilowatt hour. That's compared to about 9 cents a kilowatt hour for natural gas and 5 cents a kilowatt hour for modern coal-burning plants, as well as 5 cents a kilowatt hour for wind energy. The good news is that solar power used to cost $1 a kilowatt hour. As new technologies are ushered in, the hope is that prices will fall to around 6 cents a kilowatt hour in the next decade.

Right now, solar energy provides less than 1 percent of all energy needs in this country. If all goes according to plan, it could provide up to 2 percent of the nation's generation mix by 2025, the Bush administration says.

Advocates have much greater aspirations, saying that solar energy will heat up and ride the next big economic wave. Its ultimate rise will undoubtedly be attributed to an almost perfect storm that includes rising fossil fuel prices along with government directives that provide incentives. General Electric, which makes solar panels now used in several states, is expecting breakthroughs in the global market as well.

Clearly, more research is necessary. And that's why solar lobbyists and lawmakers in states with solar potential want the current administration's tax credits to extend beyond 2007. And the public supports it. Solar power plants have almost no carbon dioxide, sulfur dioxide or nitrogen oxide emissions tied to them. Because they usually produce power during peak demand when it is most needed, they are displacing coal and natural gas fired units in the process.

"The key is to start using concentrating solar power to boil water with sunlight and mirrors instead of by burning coal," says Leslie Glustrom, an activist with Clean Energy Action in Boulder. "Then, for places outside of the Southwest, we should be shipping solar (and wind) electrons using high voltage lines instead of trying to ship ever-pricier coal over our aging 19th century railroad system. We have more than enough sunshine in the southwest to run the country many times over-but we have to shift our thinking."

Growth in the sector won't be quick. But concerns over air quality along with government mandates are giving manufacturers the certainties they need to make expensive investments, and to ultimately prosper. That's behind the recent wave of innovation and the proposed build out of a new solar system in the Southwest. Supporters are enthusiastic. But, consumers need to know if it will be cost effective and reliable

More information is available from Energy Central:

• Generation Technologies Topic Center

• Nevada's Huge Solar Plant - The Promise of Parabolic Mirrors, EnergyBiz, May/June 2006

• Solar Gains Momentum - Technology Ready to Stand on its own w/o Gov. Subsidy, EnergyBiz, Sept/Oct 2006

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