Say you have a proposal from a solar installation company, and they have told you that the modules they use are all “Tier 1”. Maybe they said something about their competitors using Tier 2 or Tier 3 modules. What exactly is this “Tier” system?
The term “Tier 1 solar modules” refers to Bloomberg New Energy Finance’s (BloombergNEF) quarterly list of “Tier 1” modules. There is no similar published list of Tier 2 or Tier 3 modules. Tier 1 refers to the “bankability” of these modules. Bankability, in other words, is the extent to which projects that are greater than 1.5 MW and using the solar products are likely to be offered non-recourse debt financing by banks. In this context, BloombergNEF takes non-recourse debt financing as a signal of confidence on the part of lenders that the project, using these specific products, will perform as expected. Voila, bankability.
However, BloombergNEF’s own published methodology document says of the Tier 1 classification, “This classification is purely a measure of industry acceptance, and there are many documented examples of quality issues or bankruptcy of tier 1 manufacturers.” Tier 1 is not a measure of PV modules’ quality or reliability.
Another helpful note from BloombergNEF’s published methodology:
“We strongly recommend that module purchasers and banks do not use this list as a measure of quality, but instead consult a technical due diligence firm such as RINA (formerly OST Energy), ATA Renewables, Wood Plc, PVEL, Black & Veatch, TUV, E3, STS Certified, Clean Energy Associates, PI Berlin, Pvbuyer, Enertis, Oravia, Leidos Engineering, the Austrian Institute of Technology (AIT) or Phoventus. These would usually consider what factory the module comes from, as well as the brand, and give an informed opinion on whether the modules will perform as expected.”
Many of these organizations do not make their evaluations readily available to the public, however.
So where can someone find good information on reliability and performance of PV modules?
In MREA’s Grow Solar programs, installer selection committees award points for Tier 1 and top performing modules on lists published by PVEL and RETC. All three of these lists are free and readily available.
PVEL publishes an annual Module Reliability Scorecard. The premise of this evaluation is that “Certifications and warranties are important prerequisites for global market acceptance and financing of solar PV technologies. However, certifications do not ensure PV module reliability and warranties do not provide full protection for asset owners when failures occur in the field.”
RETC’s annual PV Module Index “is made to be as direct as possible. It’s as simple as this: manufacturers selected as a High Achiever by RETC have to tick off all the checkboxes, not just the best in one category.”