Global oversupply of PV modules has pushed some suppliers to cut costs, with consequences for quality. Attendees of pv magazine Week Europe’s quality-focused third session heard how tight margins can have knock-on effects that risk project bankability, and what can be done about it.
Six industry experts from across the solar value chain joined the 90-minute live broadcast on Dec. 2 to answer questions on common failures, if AI can identify faults before they happen, how a developer secures more than GBP 300 million in project finance, why is there so much variation between EPC quality, and more.
Jörg Althaus, director of engineering services and quality assurance at at Intertek CEA set the scene for the session by sharing quality insights from the field and some updated recommendations on how to avoid some of the most common failures, such as glass breakage on PV modules.
“Until recently, module manufacturers were building glass polymeric backsheet sandwiches with 3.2 mm fully tempered glass. Nowadays, they have moved to 1.82 mm rear and front glass, partially tempered,” Althaus explained. “At the same time, the frame has changes its design and has become a little bit weaker and the module has become bigger.”
The Intertek CEA director told attendees he wanted to be clear that glass breakage may have multiple reasons: there could be a material issue, a design issue, a combination of the module and the mounting structure. Intertek CEA has updated its recommendations to ensure more stringent checks on material quality, and Althaus also highlighted where typical module tests may be falling short.
“One important point is there that when testing is done for PV modules, it's typically done on a uniform load according to IEC standards. While in reality, the racking manufacturers will test their system in the wind tunnel, which provides a non-uniform load. The combination of both is hardly tested,” Althaus said. “Our recommendation is to do field representative testing of the actual module mounting method with the representative parts from the mounting part to represent the real loads seen in the field to avoid any weakness.”
Faults at electronic balance-of-system (EBOS) level can also have a marked impact on project revenues over time, and a well-designed PV installation has potential to reduce costs in the long run. Josep Tienda, Vice President of International Sales at Shoals Technologies – a platinum partner of pv magazine Week Europe, joined the session to explain the company’s approach to manufacturing bankable EBOS components.
Tienda explained how – counter to the industry norm of wiring in the field – Shoals offers prefabricated EBOS solutions that reduce the number of components and connection points on a project. He also offered attendees an overview of Shoals’ testing regime and argued investing in extra quality assurance at the manufacturing phase results in fewer failures in the long run.
“Our solutions are designed and manufactured just to ensure that the inverter is protected, and you don't have any issues in terms of yield and therefore downtime,” Tienda said.
The long-run cost that balance of system procurement decisions can have on a per kilowatt hour basis was put front and center by Andrea Viaro, global head of large-scale PV business at connector manufacturer Stäubli, a pv magazine Week Europe gold sponsor.
Viaro argued connectors are small components that can cause disproportionately large financial losses, and he brought a European Commission-backed study along to back his claim.
“Many of the potential failures which happen related to connectors or DC cabling in general, which have, in fact, the highest impact in terms of financial loss per kilowatt hour in a PV installation,” Viaro explained, before presenting case studies of real-world failures. These included a project site where cross connections – connectors which are not supposed to be mated together – led to an increasing number of failures over time, as well as a rooftop PV installation where poor field assembly led to a fire.
“This led not only to troubles in terms of damages to the PV plant and then additional costs for reconstruction and rebuilding the plants, replacing all the components, but also losses of the electricity for the company which owned the plant,” Viaro explained, adding that the failure resulted in an additional €100,000 per month bill for the company due to offtaking from the grid.
Mitigating these kinds of in-field EPC failures is critical to ensuring projects are bankable and David Penalva, CEO and co-founder of SolarGrade by HelioVolta, launched the session’s panel discussion with findings from more than 300,000 data quality points.
Penalva said there were three main takeaways from from HelioVolta’s research. The first is that quality varies significantly among EPC, “up to three orders of magnitude,” the second takeaway is that the EPC company size, years of experience or location “doesn’t really matter,” and the third was that 67% of EPCs studied did not meet the quality standards set by HelioVolta.
Attendees heard how there are three steps to getting better quality work from EPCs. These were ensuring quality issues are measured, taking action to change practices, and monitoring EPC processes – potentially by a third-party auditor.
“When we track a few EPCs and their subcontractors over three years, the period of three years overseeing them, we saw a reduction in issues per megawatt of up to 60% year over year, which is a huge amount,” Penalva said.
Tim Humpage, CEO of British Solar Renewables, joined the discussion with his own perspective on EPC work. British Solar Renewables operates on a model that sees the company develop projects that are built by its own in-house EPC. Humpage highlighted the company’s record of more than 1.5 GW built with 99.86% capacity across the fleet.
British Solar Renewables had made headlines earlier in 2025 by securing a $450 million debt raise and Humpage acknowledged that financing forces British Solar Renewables to think about supplier quality early in the development process.
“It helps having an in-house EPC because effectively you can appoint your EPC before you hit financial close, so it ties up a lot of those chicken and egg issues that lots of other people have,” he added. The other key bankability challenge raised by Humpage related ethical procurement and the CEO noted that British Solar Renewables has worked with SolarPower Europe and Solar Energy UK on the issue.
Assessing what equipment is bankable for a PV project is key for funders and Govinda Upadhyay, CEO of SmartHelio revealed he is increasingly being asked to share his findings on equipment faults. SmartHelio offers operation and maintenance (O&M) software designed to predict faults before they happen. The Swiss company’s AI-powered software tool detects signals in current and voltage patterns in a bit to prevent ground faults and other DC issues before they happen. Upadhyay said the goal was to move operation and maintenance to a predictive mode, an approach he compared to preventative medicine as opposed to symptom treatment.
“A lot of my customers come to me and tell me, Govinda great you have a lot of data. Tell me which inverters, which BOS system, which connector, which panel is better for me? And I think this king of intelligence is very important for people,” he said. “Funders are asking these questions. They are worried about their investments and they want to know that, okay, these guys have given me this proposal, what do you think about it? Does it make sense for my money to be there?”
Catch up on the entire pv magazine Week Europe session:
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