Huge photovoltaic modules, in danger!

Recently, meteorological agencies in multiple countries have issued high-level warnings, indicating that a "super El Niño" that could reshape the global climate pattern is rapidly approaching from the end of 2026 to the beginning of 2027. For China's photovoltaic industry, this means that extreme weather events such as typhoons, strong gusts, and blizzards are transforming from "black swan" events into "gray rhinos." As the core power generation unit of a power plant, the adaptability to extreme environments, structural stability, and load safety of solar panels will directly determine whether they can withstand countless extreme weather events throughout their 25-year lifespan.

However, a recurring but often overlooked industry issue is that the shortcomings of ultra-large-size photovoltaic modules are becoming increasingly apparent under normalized extreme weather conditions. Their comprehensive ability to cope with harsh operating conditions has become a critical issue that urgently needs to be examined.

The "Triple Blow" of El Niño

El Niño is not an abstract meteorological term, but a crucial test that photovoltaic power plants must face. When global atmospheric circulation becomes abnormal, my country's densely populated photovoltaic (PV) installation areas are facing the combined impact of three extreme weather events:

First, frequent and intensifying typhoons and strong gusts. The number of typhoons forming in the Pacific has increased, and their landfall intensity is stronger than usual, significantly raising the probability of severe convective weather in coastal and inland areas. For PV power plants, this means that repeated alternating gusts have become the norm, and the modules are no longer subjected to single wind pressure events, but rather to high-frequency dynamic fatigue.

Second, extreme heat waves. The number of days with extreme high temperatures in summer is increasing, and the surface temperature of modules frequently exceeds 70°C. The difference in thermal expansion coefficients between glass, frames, and cells is amplified at high temperatures, leading to a continuous increase in internal stress accumulation.

Third, extreme precipitation and blizzards. The increase in torrential rains and floods in the south and extreme blizzards in the north significantly increases the probability of non-uniform loads on the module surface, while high humidity accelerates material aging.

These three characteristics correspond precisely to the three fatal challenges facing PV power plants: dynamic fatigue, thermomechanical stress, and non-uniform ultimate load. Ultra-large modules are almost entirely failing in all three dimensions.

The Physical Dilemma of Ultra-Large Modules: When Area Expansion Meets Natural Laws

Ultra-large modules, measuring 2384mm × 1303mm and above, have a total area of ​​3.1㎡ and above, representing at least a 15% increase in area compared to the industry standard module's 2.7㎡. However, both types of modules use the exact same 2mm thick glass; the ultra-large modules lack any material upgrades or thickness reinforcement design, amplifying potential risks.

Deformation is the first crack. Test data shows that even under natural static conditions, the glass deformation of ultra-large modules is already twice that of standard modules; under maximum load, the glass deformation soars to three times. This significantly increased deformation keeps the module glass under prolonged overload, easily leading to irreversible damage such as glass breakage, microcracks in solar cells, and encapsulation delamination, drastically shortening the module's lifespan.

Fatigue is the second crack. In El Niño years, typhoons and severe convective weather bring not one-time impacts, but a relentless "fatigue war" of repeated gusts. Standard modules can reliably withstand 20,000 cycles of dynamic load testing at ±1500Pa, maintaining structural integrity and performance degradation throughout, demonstrating exceptional dynamic fatigue resistance. In contrast, ultra-large modules, under the same ±1500Pa dynamic load conditions, begin to show signs of failure after only 2,000 cycles, exhibiting only 10% of the dynamic load tolerance of standard modules.

As gusts of wind repeatedly lash the module surface, the frame and glass gradually loosen due to fatigue, eventually collapsing completely at a critical point. This is why, after extreme weather events, we see "kite-like modules" scattered on the ground—frames torn, entire modules detaching, and the modules breaking free of the support system like kites with broken strings, causing devastating damage to power plant assets.

Ultimate pressure resistance is the third major obstacle. Multiple authoritative experimental data confirm that standard modules can withstand non-uniform loads up to 6500Pa, while ultra-large modules can only reach 4300Pa, representing a 30% reduction in ultimate pressure resistance. In extreme wind tunnel simulation tests, standard modules can withstand wind speeds exceeding 60 m/s, while ultra-large modules experience structural failure under wind speed conditions of 45 m/s.

For the frequent extreme weather events during El Niño years, 45 m/s is not a theoretical value in the laboratory, but a real-world test faced every year. An extreme blizzard in the north or a strong convective wind in the south can be the final straw that breaks the back of ultra-large modules.

Same wind conditions, different outcomes: The direction given by regulations

In 2022, a 300MW photovoltaic power station in Northwest China became a typical case of ultra-large module failure due to extreme weather. The project site is located in a typical high-risk climate area with frequent sandstorms and extreme gusts, and the relevant extreme weather events are predictable and controllable. However, the project used ultra-large modules throughout its construction without optimizing the selection based on the regional climate characteristics.

At the time of the accident, the area experienced gusts exceeding level 13. Following the severe weather, the power station suffered extensive damage to its modules and support systems, resulting in substantial direct economic losses and long-term power generation revenue losses. However, several other photovoltaic projects in the area using standard modules experienced only minor damage under the same extreme weather conditions, with their power stations operating smoothly and unaffected. This vividly illustrates the shortcomings of ultra-large modules under extreme conditions.

Faced with the escalating El Niño effect, the national government has provided a clear solution—the recently issued photovoltaic module energy efficiency standards are reshaping the industry's selection logic from a policy perspective. Energy efficiency standards incorporate module conversion efficiency, low degradation characteristics, and high-temperature performance into a comprehensive evaluation, while the "Photovoltaic Module Safety Requirements" impose mandatory requirements on module mechanical load, frame strength, and electrical safety. These regulations convey a clear and firm message: safety is the bottom line, efficiency is the direction, and size expansion is not the answer.

Increasing module size is one means for the industry to reduce costs and increase efficiency, but it must never come at the expense of structural safety. The problems currently exposed in ultra-large modules, such as excessive deformation, insufficient load capacity, and lack of safety margin, are no longer low-probability hazards under normalized extreme weather conditions, but rather frequent and certain risks. For investors and builders of photovoltaic power plants, it is urgent to abandon the "size-only" selection mindset and prioritize the long-term reliability of the modules.