The World’s Largest Planned Solar Plant Switching 500 MW from Concentrated Solar Thermal to Photovoltaics

Nothing happens very quickly in the energy sector. That’s why the rapid economic change in solar PV is such a fascinating story — the downward cost curve for modules looks more like what we see in consumer electronics, not in energy technologies.

Given that trend, today’s news probably isn’t a huge surprise: The two companies responsible for the development of the world’s largest solar plant — the 1,000 MW Blythe Project in Southern California — said they would be using photovoltaics in place of concentrating solar power for the first 500 MW phase.

Solar Millennium and Solar Trust of America received a $2.1 billion loan guarantee for the first phase of the project earlier this year. It was originally going to utilize parabolic troughs, but will now be all PV.

GTM Research Senior Analyst Brett Prior estimates that the installed cost of 500 MW of parabolic troughs at the Blythe site is about $5.79 a watt. Today, with PV prices so low, the project could pencil out to $3.40 a watt with crystalline-silicon PV.


“My sense is that with the CSP version, even with subsidized debt, Solar Trust of America couldn’t get direct/sponsor equity investors to sign on, as the expected returns must have been too low,” explains Prior to Climate Progress.

This brings the total capacity of CSP-to-PV conversions to 2,999 in the U.S., according to GTM Research:

Alpine SunTower 92 MW (NRG/eSolar)

New Mexico SunTower 92 MW (NRG/eSolar)

Calico 850 MW (Tessera/SES)

Imperial Valley 709 MW (Tessera/SES)

Beacon 250 MW (NextEra)

Ridgecrest 242 MW (STA)

Agua Caliente 280 MW (NextLight)

Blythe phase I 500 MW (Solar Millenium/Solar Trust of America)

Total: 2,999 MW

Solar Millenium and Solar Trust of America say they’re still committed to CSP. But like so many other companies, the market conditions are strongly favoring PV — a technology that can be deployed much faster and cheaper.


Expect the trend to continue as a chronic oversupply of PV modules keeps prices depressed and hardware/power electronics companies also continue dropping costs and increasing reliability.