Its Sunny In Spain  

TreeHugger reports that Acciona has received the go ahead for 2 more 50MW solar thermal power plants in Spain.

It was only a couple months ago that we wrote about Torresol's plans to build 3 new solar thermal power plants in Spain (price tag: $1.24 Billion). The good news keep rolling in and now it is Acciona Energia's turn to announce a 500 million euros investment (about $775 million) into 2 new solar thermal plants in Palma del Río, Cordoba, in southern Spain. Each will have a capacity of 50 megawatts and together they should be able to power 75,000 homes, or 244 million kWh a year. They should be operational in 2010.

"The plants will cover the area of about 260 hectares, or 364 soccer fields, comprising 1,520 solar collectors and a truly mind boggling 364,800 mirrors which will focus the sun’s rays into the collectors. "

This story is a few weeks old but I forgot to post it at the time - Red Herring on US solar thermal company eSolar's plans to make solar power cheaper than fossil fuels.

eSolar, whose large-scale solar power facilities are designed to rival coal-powered plants, has closed on $130 million in funding from Idealab, Oak Investment Partners, and Google.org, the company said Monday.

The Pasadena, California, company, which competes against companies like Ausra (backed by Khosla Ventures) and SolarReserve (funded by United Technologies), plans to build a demonstration facility at an undisclosed location in Southern California later this year, said Rob Rogan, eSolar's executive vice president, corporate development.

"We believe we've cut the cost of solar energy in half," he said, without providing a firm cost per kilowatt hour. "eSolar believes we'll be competitive with fossil fuels.

eSolar plans to use prefabricated modules manufactured oversea to cut the cost of building a solar power plant and allow utilities to build them closer to the cities that will draw their current.

Rather than use mirrors that can run to 100 square meters as other thermal solar systems do, eSolar uses mirrors that are about one square meter. Mr. Rogan said the smaller mirrors give eSolar a 10-fold advantage in concentrating sunlight aimed at tanks filled with water that is turned to steam, which is used to turn steam turbines.

Mr. Rogan acknowledged, however, that the 70-person company's proposed 33-kilowatt power plants, large enough to power 10,000 to 25,000 homes, will be cost-effective only in regions with abundant sun like Caloifornia, Nevada and Australia.

Still, Bill Gross, eSolar Chairman and founder of Idealab, said in a statement that the business model will allow the company to compete against plants fueled by traditional fossil fuels.

“eSolar’s primary business goal is nothing short of making solar electricity for less than the price of coal, without subsidies,” he said.

More at Cleantech.com.



Renewable Energy World has a look at the question - which is cheaper, solar thermal or photovoltaics ?

The short answer would be that on an apples-to-apples comparison in the southwestern United States, concentrating solar thermal parabolic troughs (CST) have a lower levelized cost of energy (LCOE) per kilowatt-hour (kWh) than photovoltaics (PV) today. Outside of the broad southwest (which includes 7-8 states), PV is really the only game in town (at least for now, a CST project in Florida not-withstanding).

Looking forward, PV probably has a faster cost reduction curve than CST and their LCOE will cross paths within the next five years, i.e. PV will become cheaper. Concentrating photovoltaics (CPV) is the wild card that could also reach parity with CST over the next ten years.

The next obvious question is that given cost parity between the three technologies, which one is preferred by utilities?

The cost of energy is not the only criteria for utilities seeking renewable energy. The ability to generate during periods of high demand, including into the evening, makes any renewable technology much more valuable. Additionally, minute-to-minute operating characteristics on the grid, such as the potential for rapid changes in output, are also important, especially at the utility scale.

CST projects can offer both better peak capacity characteristics, with 6-8 hour thermal storage, as well as a smoother short-term fluctuations. Intermittent clouds going over a PV system will cause output to spike widely. But with a CST plant, which has thermal inertia in the heat transfer fluids, an operator can have some warning of the clouds, slow the fluid flow rate, which increases the fluid temperatures, and ride through short-term cloud events. (For reference, a wind turbine probably falls somewhere between the two technologies-there is kinetic inertia in the wind and the turbine blades, which provides a somewhat better short-term profile than PV.)

Of course, utility scale storage technologies for PV are being developed, and in some cases demonstrated. Initially these will provide similar ride-through capabilities during short-term cloud events, but as the storage technologies scale-up, they could potentially offer hourly storage into the evening. But right now in the southwest, CST has the cost and storage advantage, but PV essentially has a geographic monopoly everywhere else.