Technical Due Diligence Considerations for Bifacial PV Modules
Bifacial PV modules are growing in popularity, with growth initially spurred by favorable tariff exemptions and subsequently driven by strong economics. Independent engineers are frequently called upon to evaluate bifacial modules for a wide range of projects, from large California solar farms to community solar projects in Massachusetts. While there is substantial literature on the energy modeling of bifacial PV modules, proper due diligence requires addressing a number of other considerations, including:
Durability: Each manufacturer takes a unique approach to tradeoffs between cost, weight, and durability and investors must consider this when evaluating modules. For example, while glass may be more durable than most polycarbonate materials it can be prone to cracking when the glass is too thin or the module is not supported by a robust frame. On the other hand, the lighter polycarbonate materials may be too flexible or become cloudy under prolonged UV exposure.
Sourcing: Many US projects are sourcing PV modules outside of China and it is important to ensure that these new factories have been properly reviewed, even if they are part of a larger, already reviewed, parent company. It is also critical to ensure modules have the proper market-level certifications and that claims for bifaciality, degradation, and other characteristics are within expected ranges.
Productivity: While an extra 5%-10% generation may seem like a “no brainer”, bifacial modules are not the answer in every situation. High efficiency monofacial modules may compare favorably in some cases, so it is important to carefully evaluate energy models to ensure the best modules are selected for the specific project constraints. It is also important to evaluate the site and O&M procedures to ensure that albedo expectations (whether based on ground measurement or satellite data) are realistic for the whole project life.
This poster will help investors, developers, and asset owners better understand the nuances of bifacial PV modules at the project level and provide tools and insights to help market actors make informed decisions through good due diligence.