Solar Reliability: Top Performers Amid Rising Failures

A paradox is unfolding at the heart of the global solar industry, a sector celebrated for its relentless innovation and pivotal role in the clean energy transition.

While the number of elite solar module manufacturers achieving “Top Performer” status remains robust, a startling undercurrent of increasing failures is casting a long shadow over the broader market.

This dichotomy, laid bare in Kiwa PVEL’s 11th annual PV Module Reliability Scorecard, released this week, serves as a potent reminder that not all sunshine is created equal.

Kiwa PVEL, the independent laboratory renowned for its rigorous quality and reliability testing of solar photovoltaic (PV) modules, has delivered a nuanced, even unsettling, report.

On one hand, the 2025 Scorecard celebrates 50 manufacturers as “Top Performers” in at least one of its demanding tests.

A select nine of these have even managed to earn this coveted designation across all seven critical test categories for at least one module type, demonstrating a remarkable commitment to excellence.

Yet, beneath this veneer of success, a concerning trend emerges: an unprecedented 83% of all module manufacturers evaluated experienced at least one test failure.

This figure represents a significant leap from the 66% reported in the 2024 Scorecard, which itself was a record high at the time.

This isn’t merely an academic exercise in laboratory statistics.

The Product Qualification Program (PQP), Kiwa PVEL’s flagship testing suite, simulates years of real-world environmental and mechanical stresses—from extreme temperatures and high humidity to the relentless impacts of mechanical stress, hail, and ultraviolet light.

The results from these tests directly translate into the long-term performance, reliability, and ultimately, the profitability of solar projects around the globe.

The mixed bag of results across various PQP tests highlights the complexities inherent in a rapidly evolving technological landscape.

While some critical metrics, such as PID (Potential Induced Degradation) and PAN (Performance at Normal Operating Conditions), show signs of improvement, other vital indicators are trending in the wrong direction.

The module breakage rate for Mechanical Stress Sequence (MSS) and Hail Stress Sequence (HSS) tests, for instance, has worryingly increased.

Likewise, while UV Induced Degradation (UVID) results are beginning to improve, they remain a source of concern for a segment of the market.

These aren’t minor glitches; increased breakage rates under stress conditions can lead to costly operational failures, reduced energy output, and significant maintenance burdens for solar farms.

Tristan Erion-Lorico, Vice President of Sales and Marketing at Kiwa PVEL, acknowledged, “The rapid pace of innovation in the PV module landscape is encouraging, and it’s great to see more products achieving Top Performer status.”

His sentiment captures the industry’s forward momentum, but he quickly pivoted to a crucial warning: “However, we continue to caution buyers not to assume all modules are created equal.

Our testing continues to uncover significant variability in performance and long-term reliability.

The Scorecard remains an essential tool for navigating these differences, helping procurement teams make smart, risk-conscious decisions.

This “significant variability” is the elephant in the room.

In an industry where long-term financial commitments underpin multi-million dollar projects, the difference between a highly reliable module and one prone to early degradation or failure can be catastrophic for returns on investment.

For solar project developers, financiers, and asset owners, the Scorecard transcends a simple ranking; it becomes an indispensable due diligence instrument, a safeguard against unforeseen operational headaches and diminished energy yields over a project’s decades-long lifespan.

Kevin Gibson, Managing Director of Kiwa PVEL, echoed this sentiment, noting that the 2025 Scorecard “reveals both the progress and the challenges that come with a dynamic PV module market.”

He emphasized the decade-plus commitment to rigorously testing modules to uncover trends, adding, “While not every test result exceeded our expectations, many did—demonstrating resilience and excellence in an evolving industry.”

The implicit message for the global solar market is clear: vigilance is paramount.

As manufacturers race to introduce new technologies and drive down costs, the temptation to cut corners on reliability can be insidious.

The fact that only 21 model types achieved Top Performer status in all core reliability tests, and a mere three of those also excelled in PAN, underscores how rare truly robust, all-around performance remains.

In an era where solar power is increasingly relied upon as a foundational element of national energy grids, the long-term integrity of every installed module is not just a commercial consideration but a matter of energy security.

Kiwa PVEL’s 11th annual Scorecard is more than just a report; it’s a critical barometer for a maturing industry, highlighting the ever-widening gap between the best-in-class and those struggling to meet fundamental reliability benchmarks.

It serves as a stark reminder that while innovation propels the sector forward, meticulous quality assurance is the bedrock upon which its sustainable future must be built.

The full Scorecard, a vital resource for navigating these complexities, is available online at scorecard.pvel.com.