Independent energy and certification body DNV GL reports overall improvement in global solar PV reliability with its fourth edition PV Module Reliability Scorecard report. The Scorecard reports on eighteen months of test results from DNV GL’s PV Module Product Qualification Program (PQP) of commercially available PV modules on the global market.
Tara Doyle, Head of Business Development & Project Management, explained this year’s key developments.
“Our goal with the Scorecard is to support the buyer market, the downstream partners — developers, financiers, EPCs, insurance, etc. — and help them make data-driven decisions.”
To this end, Doyle said that the Product Qualification Program is a series of tests geared toward evaluating products across their lifetime.
“We’re looking at what’s going to happen to PV panels under simulated environmental stresses over the course of the product’s useful life.”
Testing goes beyond industry standards too, “usually by two to four times,” noted Doyle.
“Included in the PQP are tests that look at performance, reliability and durability. The four test categories, thermal cycling, damp heat, dynamic mechanical load sequence and potential induced degradation, are several tests at the core of reliability and durability.”
Digging into the Bill of Materials
“We see improvement in all areas except one,” said Doyle, adding that “overall performance in the damp heat test category decreased.”
The test, featuring high temperature and high humidity to evaluate module construction, revealed median power degradation of 2.5 percent this year compared to 0.9 percent in both 2014 and 2017.
“It’s important to highlight that we’re not only testing individual components that comprise the bill of materials (BOM) but also interaction between components. Any change in components, or how the module is manufactured, can have an impact on performance and reliability of the product.”
“There were still other failures across categories,” added Doyle, explaining that the results found twenty-two percent of manufacturers experiencing one or more failures in overall testing, nine percent of BOMs failed one or more of the test criteria, and twelve percent of module types failed one or more of the test criteria.
“It’s important that the buyer community be cognizant of results as these issues can impact projects; and we’d caution the buyer community to request BOMs of the top performing models from manufacturers (something DNV GL provides).”
While over twenty manufacturers are rated as Top Performers for 2018, just four are credited with the accolade for the last three years running: Jinko Solar, Trina Solar, Hanwha Q CELLS Co., Ltd and Yingli Solar.
Manufacturers Adani (Mundra Solar PV Ltd), First Solar, HT-SAAE, LG Electronics, and Panasonic all gained Top Performer status this year for the first time.
“We see reliability and performance improving overall. That’s a trend we’ve seen over past several scorecards,” said Doyle.
A new feature of the 2018 Scorecard is a ‘Historical Scorecard’ that brings a spotlight to top performers since the first Scorecard.
“The downstream find value in single reports and tests, but also look toward performance and reliability trends of manufacturers — in other words asking, ‘Is this manufacturer capable of producing quality products?’. We’ve included the Historical Scorecard to showcase top performers.”
New Technologies Bring New Risks
While mainstream products benefit from tried and tested materials, components and processes, more cutting-edge technologies aren’t without risk.
“With new commercially available products coming to market — for instance bifacial, PERC, half-cut cells — that have not been installed in the field for long, or gone through testing as significantly as other products, there could be significant risks for buyers to consider.”
The broader, fast-moving landscape of solar PV markets, together with its pressures, underlines the importance of DNV GL’s testing activities according to Doyle.
“With PPA pricing and overall cost of energy decreasing, so is the cost of solar PV. Consequently, manufacturers especially are being forced to do more with less, and reduce costs across the value chain in order to remain cost-competitive. We see that these pressures can impact the quality of PV modules produced and so we must remain vigilant.”