With frequent extreme weather events, how can photovoltaic power stations protect themselves?

Since July, extreme weather events have become increasingly frequent across China, including floods in Guangxi, typhoons in the Yangtze River Delta region, flash floods in northern Hebei, severe convective weather in Hubei, and torrential rains in Liaoning. From Northeast to South China, multiple provinces are experiencing the impact of extreme weather.

For photovoltaic power plants, the arrival of extreme weather is also a test of their operational mechanisms. Without proper preventative measures, incalculable losses could occur.

Large areas of photovoltaic modules were submerged by floods!

Affected by Typhoon Maysak, the 10th typhoon of the year, Guangxi experienced continuous heavy rainfall. On July 6th, several reservoirs in Hengzhou City, Guangxi, experienced dangerous situations.

Previously, the Nanning Municipal Emergency Management Committee issued a notice stating that since July 4th, most parts of Nanning City had experienced heavy to torrential rain, with some areas experiencing extremely heavy rain. Water levels in some rivers rose rapidly, and some reservoirs experienced serious emergencies, making the flood control situation severe. According to the "Nanning City Flood and Drought Relief Emergency Plan," the flood control emergency response in Nanning City was upgraded from Level III to Level I at 11:30 AM on July 6th.

Passengers on high-speed trains filmed large areas of ground-mounted photovoltaic power stations in Guangxi being submerged by floodwaters. Furthermore, in some severely flooded areas, the floodwaters had already inundated parts of these photovoltaic power stations, and large-scale photovoltaic power stations were visibly damaged to varying degrees.

More important than the damage to these photovoltaic modules is the electrical safety issue. Since photovoltaic power stations are themselves power generators, when these power generation devices are submerged, if broken live cables fall into the floodwaters, the entire flooded area will carry a dangerous voltage.

It is impossible to determine whether the water surface is electrified with the naked eye. If rescue personnel accidentally enter, they are at high risk of step voltage electrocution, a scenario of extremely high risk.

Meanwhile, videos posted online show that some rooftop photovoltaic power stations, due to insufficient stability, were completely washed away by the floodwaters. Some component frames were deformed, cables were swinging wildly, and large amounts of rainwater were pouring in.

Strong winds overturned photovoltaic power stations in Hubei and Zhejiang!

Over the past two days, Typhoon Bavi made landfall in the Jiangsu, Zhejiang, and Shanghai regions. On July 11th, Bavi made landfall along the coast of Kanmen Street, Yuhuan County, Taizhou, Zhejiang Province, and then made a second landfall around midnight on July 12th in Qingjiang Town, Yueqing County, Wenzhou, becoming the strongest typhoon to hit my country this year. The villages of Yingdong and Dongsha, located near the coast, were situated close to the typhoon's landfall points.

According to reports, a company in Taizhou, Zhejiang Province, suffered significant losses as all its rooftop solar panels were torn off by Typhoon Bavi.

Notably, in contrast, a homeowner in Wenzhou, Zhejiang Province, opted for proactive protection against the typhoon.

It is understood that to prepare for Typhoon Bavi, a homeowner in Wenzhou chose to dismantle and preserve all the solar panels on his roof before the typhoon struck. Last year, this homeowner invested in and constructed a solar panel project covering approximately 1,000 square meters on the rooftop of a high-rise building near the sea in Longwan District, Wenzhou.

The homeowner stated that dismantling and reinstalling would indeed incur additional costs of several thousand yuan, but the main concern was the risk of the solar panels being blown away by the typhoon and injuring others.

Meanwhile, on July 6th, Baisha Town, Yangxin County, Huangshi City, Hubei Province, was hit by severe convective weather, with sudden and strong winds causing varying degrees of damage to outdoor facilities throughout the area. The 25-kilowatt village-level photovoltaic power station in Wangwujing Village was severely damaged.

It is understood that this power station is a core revenue-generating project for the village collective. Photos from the scene show large areas of photovoltaic modules overturned and damaged, photovoltaic supports severely deformed and scattered on the ground, many photovoltaic panels broken and deformed, and transmission lines broken and detached. This not only caused significant losses but also created multiple safety hazards at the disaster site, including potential for electrical leakage and falling debris.

With frequent extreme weather events, how can photovoltaic (PV) power plants protect themselves?

Faced with these unforeseen circumstances, how can PV power plants avoid losses or minimize them? For owners, PV power plant protection cannot rely on last-minute efforts; instead, a comprehensive lifecycle protection system covering site selection, design, operation and maintenance, emergency response, and insurance should be established.

Firstly, in terms of site selection, risk avoidance is crucial from the outset. During the planning stage, risk assessments must be conducted based on historical weather data and the probability of extreme weather events. Avoiding floodplains and high-risk areas for geological disasters is a fundamental requirement. The Ministry of Housing and Urban-Rural Development's mandatory standard, "Specifications for Solar Power Generation Engineering Projects (Draft for Comments)," clearly requires that the flood control standard for PV array areas should not be lower than a 30-year high water (tide) level. This means that hydrological conditions must be fully considered during site selection, and complacency is unacceptable.

In terms of design, PV modules should employ double-row piles and diagonal bracing to enhance the pull-out resistance of the support foundation, and the connection between the module frame and the clamping block should be reinforced to prevent tensile failure. The safety level of photovoltaic (PV) mounting systems should not be lower than Level III, and the safety level of the mounting foundation should not be lower than the safety level of the upper structure. Tracking systems should have the capability to position themselves in a safe posture.

Furthermore, the protection level of outdoor electrical equipment should not be lower than IP54. Inverters, combiner boxes, transformer substations, and energy storage compartments should be reinforced with enhanced sealing and waterproofing, raised bases, and additional water-blocking and drainage facilities. Low-lying sites should be equipped with pumping equipment in advance, and water ingress points should be sealed to prevent water damage, short circuits, and explosion risks.

Besides preliminary preparations, a lack of routine maintenance can lead to failure at critical moments.

It is important to know that the 24-48 hours before a typhoon is a critical window that determines the fate of a power station. Before extreme weather arrives, it is necessary to inspect the central pressure blocks, side pressure blocks, and fixing bolts, and tighten, replace, or repair any loose, rusted, or missing fasteners. Check the crossbeams and vertical beams of the mounting system for bending, deformation, and cracks. Older power stations, windward roofs, and large-span arrays should be reinforced with wind-resistant bracing rods and counterweight sandbags. With the frame of the solar panels constantly exposed, inadequate daily inspections can lead to problems such as loose fasteners and rusted or cracked brackets, which can be amplified by strong winds.

Replace any aged or worn-out seals on the inverter and combiner box cabinet doors immediately. Seal cable entry holes and gaps in cable trays to prevent rainwater backflow. Inspect AC and DC cable joints to prevent leaks and sparks during rain.

In the event of severe extreme weather, one can choose to completely disassemble and preserve the solar panels, as mentioned by the Zhejiang homeowner, and reinstall them once the weather returns to normal. While this incurs additional installation and disassembly costs, it is far less than the loss of the entire power station being overturned and destroyed.

Of course, even with the most comprehensive protection, the destructive power of extreme weather can sometimes exceed expectations. In such cases, insurance is the last resort to mitigate losses.

Solar power station natural disaster insurance covers equipment damage caused by earthquakes, floods, typhoons, hail, sandstorms, etc., with compensation based on actual losses. Complete destruction may be compensated based on replacement cost. However, it should be noted that defects in the equipment itself, excessive use, and aging are not covered.

Currently, the insurance industry is also constantly innovating. Some institutions have launched financial products such as "carbon asset weather insurance." Financial regulatory departments in some regions are guiding insurance institutions to develop comprehensive insurance products covering property damage, power generation revenue loss, and public liability.

Are photovoltaic power plants still suitable for areas prone to extreme weather?

With the increasing frequency of extreme weather events, a real question is emerging: are photovoltaic power plants still suitable for these high-risk areas?

The answer is yes, but the requirements must be raised. First, it's crucial to understand that extreme weather is not a "terminal illness" for photovoltaic power plants. Related reports indicate that most photovoltaic power plants, with proper site selection, design, and maintenance, can withstand most extreme weather events.

In the future, building photovoltaic systems in these areas will require meeting high standards across multiple dimensions, including site selection, design, operation and maintenance, and insurance. From an industry trend perspective, the disaster prevention system for photovoltaic power plants is shifting from traditional "post-disaster repair" to a comprehensive model of "pre-disaster structural reinforcement, equipment upgrades, intelligent management and control, and differentiated layout."

After all, the future of the photovoltaic industry depends not only on improving power generation efficiency and reducing costs, but also on whether it can safeguard its safety in the face of increasingly severe climate challenges.