First Solar

Developers of the giant Blythe Solar Power Project in California have switched from solar thermal technology to photovoltaic solar panels, one of a string of similar changes at large-scale solar projects.

Solar Millennium today said that the first 500-megawatt phase of the Blythe plant will use photovoltaic (PV) panels because the economics work better.

The company earlier this year had received a conditional loan guarantee from the Department of Energy to develop a concentrating solar thermal plant, where heat from mirrored troughs makes steam that is passed through a turbine to generate electricity. But Germany-based Solar Millennium and its U.S. subsidiary said it will use commercial financing and PV technology instead.

Seven other utility-scale solar projects in the southwest U.S. have decided to scrap concentrating solar power (CSP) for PV. All told, that's about 2,515 megawatts of solar capacity that has converted, according to GTM Research analyst Brett Prior.

The moves underscore how falling costs have improved the competitiveness of PV for large-scale projects. Solar PV prices have fallen by more than 50 percent over the last two years, making them more attractive to both the energy developer and institutions putting up the money to finance these projects.

A few other large solar thermal projects in the pipeline will also likely go with PV technology, Prior said. "This is the first (technology change) where they explicitly said that that economics drove the decision," he said. The other proposed solar thermal projects switched to PV for different reasons. For example, one had planned to use a relatively new solar thermal technology which commercial banks were unwilling to provide loans to.

Solar Millennium hasn't yet chosen which technology it will use for the second half of the 1,000 megawatt project, which is projected to be the largest solar plant in the world. But the company said it remains committed to CSP in other countries. Solar thermal plants also have the ability to add storage using molten salt.

"The advantages of CSP as a grid-stabilizing renewable energy source with storage capabilities are obvious and highly valued by utilities elsewhere in the world. They will soon become systematically acknowledged in the US, as well. This includes the use of hybrid PV/CSP plants," CEO Christoph Wolff said in a statement.