Next generation solar power could replace fossil fuels says WRI

News 25th June 2009 : London

Next generation solar power could replace fossil fuels says WRI

Concentrating solar thermal (CST) power has the potential to provide power on the margin of the demand curve, as well as replacing coal at the core of the power mix in the US, according to a report by the World Resources Institute (WRI.)

CST uses reflective material to concentrate the sun's rays to power steam turbines or engines. When combined with thermal storage CST can generate electricity on demand by storing heat in a transfer fluid like water, oil or molten salt and enabling a plant to produce power under cloud cover and after the sun has set, according to the report.

It can also be integrated with other kinds of backup power. "We are seeing hybrid systems deployed which involve adding CST technology to the natural gas combined cycle plants so you end up with a hybrid plant which uses solar when the sun is out and uses natural gas when it isn't. This results in a huge emissions reduction compared to a coal is plant of the same size," says Britt Staley associate at WRI and lead author of the report.

CST replaces lifetime fuel payments with upfront capital in its cost structure but the upfront investment is significant and is increased further by adding thermal storage. However, costs are expected to decline as new capacity comes online because of the low operating costs. "It also enables companies to make back those costs, as CST plants with storage can produce power at 6pm when power is most expensive and can compete with natural gas peakers on the grid," says Staley.

CST has been disadvantaged by high commodity prices as plants require large volumes of glass, cement, and steel and future price trends have a significant impact on the cost of power and its competitiveness with coal. The report says that key areas of cost improvement will come through research and development (R&D) and Federal and state policy support will also help bring down costs over time.

The most generous incentives at present are provided through Spain's feed-in tariff. "Particularly in the US we have the solar resources for CST but to really take full advantage of that potential we will need new infrastructure to get that power from where solar resources are good, to where urban centres of demand are," says Staley. "In the near term, deploying CST will be like building any other power project, you have to figure out where and how you are going to connect to the grid," she says.

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