Real-life PV failures, human-induced degradation and what the industry can learn

Coming back from EU PVSEC 2026 in Rotterdam, one topic remains especially important to me: module reliability does not end at the factory gate.

At this year’s EU PVSEC, I presented examples of real-life PV module failures and what I describe as Human Induced Degradation (HID). Alongside the talk, our contributions also covered outdoor measurements of shade-resistant PV modules and the temperature behaviour of different cell technologies under reverse bias.

Quality is more than a “good” module

The PV industry has made enormous progress in manufacturing quality and module efficiency. Yet modules that leave production in good condition can still be damaged during transport, handling, installation or operation and maintenance. These post-production influences matter because their effects can appear later in the field, where identifying responsibility becomes considerably more difficult.

Why this becomes a commercial issue

When a failure appears in operation, the manufacturer is often the first party confronted with a warranty claim. But the root cause may sit elsewhere in the project chain. Without adequate incoming inspection, documentation and diagnostics, distinguishing a manufacturing defect from transport or installation damage can become challenging for manufacturers, EPCs, investors and asset owners alike.

Partial shading remains a practical reliability topic

Our work on shade-resistant PV modules addresses another real operating condition that is often underestimated. Partial shading is not only an energy-yield issue; depending on module architecture and operating conditions, it can also influence reverse-bias stress and thermal behaviour. Understanding these effects requires looking beyond nameplate power and evaluating technologies under realistic scenarios.

From research to better project decisions

This is why I continue to value EU PVSEC: it creates a bridge between scientific investigation and problems observed in actual PV projects. Feedback from researchers, manufacturers and other industry experts helps turn individual observations into broader lessons for module design, qualification, project execution and risk management.

For me, the key message is straightforward: achieving reliable PV systems requires responsibility across the complete value chain — from module design and manufacturing through logistics, installation and decades of operation.