Independent Study Finds 20% of Solar Inverters Failed Safety and Reliability Testing

May 15, 2019 by Paul Shepard

PV Evolution Labs (PVEL) today published its first PV Inverter Scorecard. It is the only publicly available report that names the solar inverter manufacturers with the best results following independent, rigorous reliability and performance tests.

The 2019 PV Inverter Scorecard is available as a free download.

While strong performance by some manufacturers confirms their attention to quality, PVEL's Scorecard also highlights significant inverter safety and performance issues:

  • One third of products tested failed Arc Fault Testing, which evaluates an inverter's ability to detect events that could lead to fires and explosions due to unsafe electrical conditions.
  • Over 20% of products tested failed Damp Heat and Humidity Freeze tests, indicating susceptibility to early lifetime failure from degradation in common field conditions such as rain and snow.
  • All tested products, including those that failed, were certified by IEC and/or UL.

PVEL's findings are aligned with independent studies that demonstrate inverters are the leading cause of maintenance calls in PV power plants and that manufacturers can underestimate annual maintenance expenses by more than 500%.

"The profitability of solar PV projects depends on inverter reliability," commented Jenya Meydbray, CEO of PVEL. "When inverters fail, financial losses from reduced energy yield are compounded by ballooning maintenance costs – and even successful warranty claims do not fully compensate asset owners."

The Scorecard summarizes test reports from the PVEL Inverter Product Qualification Program (PQP), a unique Program established by PVEL in 2014 in partnership with its network of downstream project developers, financiers and other industry stakeholders. PVEL partners can receive complimentary copies of PQP reports.

"We've seen a lot of variation in inverter performance by manufacturer and product type.  We rely on the PVEL Inverter PQP to identify the products that are likely to meet our performance and durability expectations," commented Paul Rybak, Director, Capital Procurement of Pattern Development.

"We hope our first PV Inverter Scorecard proves as valuable to the downstream solar industry as our widely recognized PV Module Reliability Scorecards," noted Tara Doyle, Chief Commercial Officer of PVEL. "As one of the first labs to test extended inverter reliability and performance specifically for the downstream market, we are pleased to lead the effort in sharing important best practices with the broader industry."