The falling price of photovoltaic (PV) solar is undermining the case for Concentrated Solar Thermal Power (CSP).

According to a recent report from Pike Research, of the 6886 MW of CSP projects awarded in the United States since 2004, 36% have been replaced with PV.  That’s more than the number which are actually under construction (1,532 MW, or 21% of announced projects), and all of those required the backing of the US DOE loan guarantee program.