Prolonged high temperatures sound the alarm for photovoltaic safety: A summary of this year's photovoltaic fires

Since the summer of 2025, many parts of China have experienced persistent high temperatures. Photovoltaic power stations, being high-voltage DC facilities permanently exposed outdoors, face amplified safety risks in the heat. Numerous photovoltaic fires have occurred in just a few months this year. While most have not resulted in casualties, they have frequently made headlines, sounding a clear warning about photovoltaic safety. Today, I will summarize and discuss why this is happening now, when it wasn't a problem before. Is it a regression in technology, or are there deeper reasons? (If you find this helpful, please like and share it with friends. We can discuss and exchange ideas in the comments section, and please correct any mistakes.)

I. Review of Frequent Photovoltaic Fires Over Time

On January 28, a large fire broke out at a photovoltaic power station on the roof of a warehouse in Zhumadian, Henan Province. While there were no casualties, the roof and some equipment were destroyed.

In March, a fire broke out in the photovoltaic panel cables on the exterior wall of a factory in Jinhua, Zhejiang Province. The fire spread rapidly along the wall, but was extinguished before reaching the factory interior.

On April 9, a fire broke out at an automotive electronics factory in Wenzhou, Zhejiang Province, due to a photovoltaic system malfunction, causing a production disruption.
On April 24, a suspected short circuit in a photovoltaic system on the roof of a factory building in Huizhou, Guangdong Province, caused a fire, again raising industry concerns.

On May 21, a fire broke out at the nation's first "sound barrier + photovoltaic" demonstration project on the Hongmeinan Road overpass in Shanghai. The fire originated in the photovoltaic components on top of the overpass sound barrier, burning through the steel structure, causing falling debris and traffic congestion. This project had only been operational for less than a month.

On May 25, a fire broke out in the photovoltaic panels on the roof of a factory on Yuanming Road in Shanghai. The fire covered approximately 10 square meters, caused by damage to the insulation layer of the DC cable, resulting in a short circuit between the conductor and the color-coated steel plate, causing a continuous DC arc.

On July 14, a fire broke out at the Xiaogang plant of Tainan Cement's Sanyuan Energy Technology Company in Kaohsiung, Taiwan. The photovoltaic facilities on the factory roof were severely damaged.

On July 21, a fire broke out in the photovoltaic panels on the roof of the Phase 1 factory building of Honeycomb Energy in Jintan, Changzhou, Jiangsu Province. While there were no casualties, this was the second fire at the facility within a year.

These cases show that photovoltaic fires have spread from remote, large-scale ground power stations to high-density urban areas such as rooftops, factories, and transportation facilities. If an accident occurs, the impact extends beyond equipment damage and may affect personnel and urban safety.

II. Analysis of Fire Causes: High Temperatures Are Only the "Trigger"

According to accident investigations and industry statistics, photovoltaic fires are mainly caused by the following reasons:

1) Hot Spot Effect (approximately 35%-40%)

When the surface of a component is blocked for a long time by bird droppings, leaves, dust, etc., the local area cannot generate electricity normally, instead consuming electricity and generating heat. In the summer's high-temperature environment, the local temperature can soar to 150℃ or even 180℃, enough to ignite the backsheet and nearby combustibles.

2) DC Arcing (approximately 30%-40%)
The DC voltage of a photovoltaic system can reach 1000V. If the wiring is loose, the insulation is damaged, or it is damp, a high-temperature arc of 3000-7000℃ can easily occur at the point of poor contact, quickly igniting the components or structural materials.

3) Loose, Aged, or Short-Circuited Electrical Wiring
Components, inverters, and junction boxes that are not securely connected or poorly sealed can lead to increased resistance and decreased insulation over time, creating a fire hazard.

4) Quality Issues Due to "Involution"

In the past two years, component prices have continued to fall, and many companies have continuously compressed manufacturing costs due to price "involution." The inevitable result is "cutting corners," reducing processes, and lowering costs, which inevitably affects product quality and lifespan. Some companies even "cut corners" in component materials, protection levels, and testing, thus creating quality hazards.

This year's "rush to install" driven by policy has led to a mixed bag of installation teams. Inexperienced contractors have not strictly followed grounding, lightning protection, and crimping standards, resulting in inconsistent system quality. This model of "low-price bidding + extensive installation" has increased the frequency of fire accidents during the high-temperature season.

5) External Environmental Factors
Extreme weather (lightning strikes, strong winds, hail), high-temperature exposure, or combustible building materials in the installation environment can all increase the risk of fire.

IV. Prevention Through Control Across the Entire Chain, from Design to Operation and Maintenance

1) Design Phase: Use components and junction boxes with high fire ratings (UL94 V-0 or higher); rationally plan wiring to reduce crossings and stacking in high-temperature areas; add fire barriers on roofs or within structures.

2) Installation Phase: Strictly follow the "Technical Specifications for Photovoltaic Power Station Projects"; ensure proper crimping of connectors, consistent models, and good grounding; provide heat insulation and flame retardant treatment for combustible structures such as metal roofs.

3) Operation and Maintenance Phase: Conduct regular infrared inspections and promptly address any abnormal temperature rises; promptly remove obstructions from the surface of components to prevent hot spots; establish arc detection and real-time monitoring systems with automatic anomaly alerts.

4) Emergency and Fire Protection: Promote component-level rapid shutdown (reducing DC voltage to below 30V within 30 seconds); install sprinkler systems and fire extinguishers in important locations such as factories and transportation facilities; establish fire emergency plans and drills.

 

In Conclusion: Safety Is the "Lifeline" of Photovoltaic Development

High temperatures are not the only cause of photovoltaic fires; they merely amplify existing defects and hidden dangers in the system. As photovoltaics are rapidly adopted in high-density urban and industrial areas, the social impact of uncontrolled safety risks will far exceed the loss of equipment itself.

Therefore, the photovoltaic industry needs to improve safety standards across the entire chain—from source materials and design to construction and installation, and finally to operation and maintenance monitoring and emergency response. Only in this way can photovoltaics, in a continuously expanding market, not only generate more power, but also do so stably and safely.