When Solar Millennium announced last week that it would switch from solar thermal to photovoltaic technology for the first 500-megawatt phase of its 1,000-megawatt solar project outside of Blythe, Calif., It drew attention to a growing trend away from CSP.

Solar Millennium issued a statement last week saying that the company felt solar photovoltaic technology would be more cost-effective. The kilowatt-per-hour cost of solar photovoltaic technology has plunged in recent years and the commercial lending options are stronger for PV than they are for utility-scale solar thermal technology.

CSP uses parabolic troughs and mirrors to heat liquid and power turbines in much the same way coal-fired electricity plants generate power. Photovoltaic technology, usually using silicon, directly converts the sun’s rays into electricity.

Solar Millennium is not the only major company recently to move away from the CSP technology for a large project.

Tessera Solar recently sold its two largest CSP projects to companies specializing solar photovoltaic technologies.

And the trend doesn’t stop there. Permitting for utility-scale solar projects in the United States have been swinging away from CSP, according to data collected and published by the Solar Energy Industries Association.

About 63 percent of existing utility-scale solar projects in the U.S. use CSP technology, while only 37 percent of the nation’s 805 megawatts of existing solar is generated using solar photovoltaics.

Another 71 percent of projects currently under construction are also using CSP technology. But the trend shifts dramatically with projects under development, which significantly outnumber later-stage projects. More than 67 percent of the almost 26,000 megawatts of planned utility-scale projects will employ solar photovoltaic technology.

That brings the total number of utility-scale projects in the pipeline that are using photovoltaics to 65 percent.

“And that doesn’t include the Blythe project,” said Solar Energy Industries Association spokeswoman Monique Hanis.

The association data is only current through the end of July, she said.

“Millennium’s switch will not be reflected in this data,” Hanis said. “The trend was already there. Before this happened, there was already a trend line toward photovoltaics.”

Growing affordability of solar photovoltaic technology and the relative simplicity and lack of need for resources like water have led to solar photovoltaic technology’s rise over CSP.

Image courtesy of SEIA.