It’s not a surprise to anyone who has worked in solar PV for years that the technology is stable and reliable. However, a large utility-scale solar project is a far more complex electrical system than the individual PV modules which it is based on.
And there are still challenges in reassuring the investment community of the reliability of utility-scale solar, given that the technology is relatively knew and that there are few large solar projects that have been around for any significant length of time.
On Tuesday, Fitch Ratings released a report which may help investors come to a more realistic understanding of the risks and reliability profile of solar projects. In this report Fitch assessed the output of five utility-scale solar PV projects and one concentrating solar power (CSP) plant, which were completed between 2011 and the fall of 2014
The report found that these projects produced an average of 9% more electricity than expected, which Fitch credits to factors including better than expected solar irradiance and lower than modeled losses for grid curtailment.
The report also found that the plants tended to have very little downtime, with annual availability factors of 98.5% to 99.5%, and that operating expenses were generally in line with expectations.
They’re off to a good start, particularly compared to wind projects, notes Fitch Ratings Senior Director Yvette Dennis. However she stresses that these are very short-term results, and that Long-term performance remains uncertain.
Mercom Capital CEO Raj Prabhu also says that the report is positive for investment in solar. "This could give some confidence to new investors in funding solar projects and have some positive impacts on interest rates," Prabhu told pv magazine.
"That said, the sample size monitored by Fitch is very small in a specific geographical area, and these findings cannot be generalized to apply to all solar projects."
The projects studied were some of the largest in the world, with three of the PV plants over 500 MW. The report looked at PV plants that were both based on multicrystalline silicon and thin film technologies, as well as a 250 MW CSP project.
Four of the PV projects and the CSP project are located in the United States, and the final PV project was built in Italy.
This article was modified at 12:00 PM Eastern Time (U.S.) to incorporate commentary by Mercom Capital CEO Raj Prabhu.