"A fire in an energy storage system (EOS) with lithium-ion batteries is complex. It's a combination of different types of fire that also develops at lightning speed." According to Cor Meedendorp, time is therefore everything to prevent unsafe situations and (collateral) damage. He is CEO of FiFi4Marine, a company that develops automated extinguishing systems for EOS.
Matter of seconds
In recent years, Meedendorp and his colleagues have tested many lithium-ion batteries for thermal runaway, a chemical process in which the temperature of a battery cell suddenly rises rapidly. For example, due to a thermal, electrical or mechanical failure. "At first, you don't see anything. Then maybe a tiny bit of smoke. And then, within seconds of popping the cell, there is a degassing and an aggressive fire that spreads to other battery cells."
In addition to the speed at which such a fire develops, it is also complex, according to Meedendorp. This is because it is a combination of different types of fire: fire class A (solids such as plastics), B (liquids such as electrolyte), C (gas fire), D (metal fire) and E (electrical fire). "And of these 5 fire classes, only A can be extinguished with water," he observes.
Time
For employees or emergency responders on site, it's all about switching quickly and gathering information, but that's a challenge. First, the fire brigade receives a notification. They then have a response time and have to make a deployment plan upon arrival, in which the safety of people is the most important. "But you don't really have that time," Meedendorp notes. "In addition, the risk of explosion that arises is more complex than fire load. A wall, or in my field a ship's hull, can protect you well against fire or fire loads. But in the event of an explosion, there is an unpredictable pressure wave. In short; Lithium-ion batteries are extremely safe, right down to the point where they are not safe. Then, all of a sudden, they are extremely dangerous in a very short time."
Selective extinguishing
The battery tests, by causing a thermal runaway and then extinguishing it with a compact foam injection, proved to be very efficient. And based on all the insights, Meedendorp's company has developed a unique extinguishing system. It takes gas and temperature measurements in every battery in an EOS. "Is only gas measured? Then there is immediately a specific message from the system and the control to turn off and ventilate only that battery. Is gas and too high a temperature measured? Then the extinguishing system is activated at lightning speed, without the intervention of a person. By the way, the compact foam that is used is a biological premix that can be used for all fire classes. This method of extinguishing the fire stops immediately. And major (collateral) damage is prevented."
Safely back to port
Meedendorp gives an example: "One of our first extinguishing systems was installed on a fully electric Danish E-ferry in 2017. The vessel has 4.3MWh of battery capacity on board, divided into 20 battery groups. Each group consists of 42 battery modules. And each module has 32 cells. That's a total of 26,880 cells. Each battery group is connected to the extinguishing system with a separate pipe. If one of the modules catches fire, the selective extinguishing starts, i.e. only on the battery group in question. In the case of the E-ferry, it means that 95 percent is saved, allowing the ship to sail safely back to the nearest port."
From the water to the land
FiFi4Marine is now also active on land, where, according to Meedendorp, the demand for EOS is increasing. "For example, when it comes to parking garages and data centres. And also think of companies that want to establish themselves somewhere, but have to deal with grid congestion. Entrepreneurs then look at the possibilities of EOS, for example in containers that are at a safe distance from the business premises. However, from an electrical and climate technical point of view, I am in favour of an EOS in the building. And that is possible with an automatic extinguishing system for lightning-fast extinguishing. Because time really is everything."
Meedendorp recently spoke in the webinar 'Extinguishing fires in energy storage systems' of the Mutual Insurers Platform of the Dutch Association. Jetty Middelkoop, Hazardous Substances Advisor at the Amsterdam-Amstelland Fire Department, was also present. She shared her experience with a fire in the energy storage system of a brand new river cruiser. Curious? Join Jetty on board.
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