French optical storage facility explodes, sending flames into the sky！

French optical storage facility explodes, sending flames into the sky！

On September 29, 2023 local time, a fire broke out in a chicken farm in the Peter Maillet district of Saint-Esprit, France. Preliminary investigation showed that the fire was caused by the explosion of lithium batteries in the photovoltaic energy storage facility.

According to reports, a total of 400 lithium energy storage batteries were running on site when the fire broke out. Staff from French electricity group EDF first disconnected the damaged device, then used water to build a barrier to protect local residents from toxic smoke, and used dry powder and foam fire extinguishing agents to control the fire.

According to STIS feedback, the fire caused no casualties, but the windows of nearby houses were blown out. At least 300 households around the fire scene felt the explosion, and nearby residents have been evacuated.

About 20 firefighters from the François, Ducos, Rivière-Salée, Vauclin and Fort-de-France barracks participated at the explosion site, providing relevant support through the French electricity group EDF, and the situation was completely under control after three hours. The fire caused many nearby houses to lose power, and power was gradually restored until the evening.

At present, the photovoltaic energy storage device of the chicken farm in France has been completely destroyed. According to preliminary estimates, the economic loss has reached one million euros.

Previously, in early August this year, firefighters from the Italian province of Treviso responded to a fire in a poultry farm shed in the city of Volpago del Montelo.

Why are PV module level shutoffs important in a fire?

There are many reasons for fires in photovoltaic power stations. Among them, the equipment with greater fire risk includes inverters, combiner boxes, cables, and components. As long as it is an electrical system, there is a risk of fire. With the advancement of photovoltaic technology, the power level, current and voltage of photovoltaic products continue to increase. The voltage of photovoltaic systems has increased from hundreds of volts to thousands of volts. Higher voltages are more likely to cause fires. Fires in photovoltaic power plants pose a big challenge to firefighters. After a fire breaks out in the system, high voltages of hundreds or even thousands of volts will still be generated. If firefighters rush to rescue, it will pose a life-threatening threat.

The difference is that if a component-level rapid shut-off is installed on the photovoltaic system, firefighters can quickly cut off the connection between the component levels. According to NEC regulations, the voltage can be reduced to 80V within 30 seconds before proceeding. save.

Do all inverters have module-level rapid shutdown capabilities?

The inverters currently on the market are mainly divided into centralized inverters, string inverters and micro inverters. Among these three types of inverters, only microinverters have the shutdown function, and the other two types of inverters currently do not have the component-level fast shutdown function. The micro inverter adopts a fully parallel circuit design, which can invert the DC power of each component into AC power and then integrate it into the grid. The DC voltage is about 60V. It has the advantage of naturally having no DC high voltage and completely solves the problem of arcing due to high voltage DC. It reduces the risk of fire and also solves the problem of photovoltaic power stations hindering rescue operations when a photovoltaic fire occurs.

However, the popular market for micro inverters is not yet large. Most of them choose conventional centralized inverters or string inverters. Therefore, these two types of inverters need to be equipped with fire-fighting quick shutdown switches. The component-level fast shutdown function can be realized. The use of component-level rapid shutdown devices is currently the simplest, most mature way to achieve this requirement.

What is a component level shutdown?

Component-level rapid shutdown is a device that can achieve component-level rapid shutdown. In the event of an unexpected disaster, the connection between each component can be quickly shut down remotely or manually, thereby eliminating the DC high voltage present in the photovoltaic system array, reducing the risk of electric shock, and ensuring the rescue safety of firefighters to the greatest extent. BLD component-level shutoff has many advantages such as safety, reliability, flexible installation, high efficiency, and low noise. Dual-pass DC input greatly reduces installation costs and complies with US NEC regulations and standards. It is small in size and light in weight and can be directly stuck on the module frame or pasted on the module backplane.