The growing concern over climate change and reducing the amount of carbon discharged into the atmosphere has led to the adoption and global acceptance of many technologies which, only a few years ago, were considered farfetched or novel at best. The electric vehicle (EV) is one such technology.
EVs are fast becoming a fixture on the world’s roads with the industry expecting sharp increases in EV deliveries. Bloomberg estimates EVs to grow exponentially—from around 3 million vehicles in 2020 to 66 million by 2040. The latter represents an astounding two-thirds of the global auto market.[i]
One thing all these vehicles will need is a charging station and the newer models feature a battery storage system and two charge points each. Actually, the vehicles will need a network of charging stations as they travel from point A to point B. EV charging is becoming an industry in and of itself. In 2021, EV charging was a $6.8 billion USD market already. By 2025, it is expected to reach over $20 billion USD with a compound annual growth rate (CAGR) of 38%.[ii]
The plethora of charging stations entering the market brings associated risks. With high-voltage electricity being transferred between charging stations and EVs, malfunctions are sure to result in a fire. While incidents of fires during charging have yet to become commonplace, they have occurred (watch one here), and with the increase in EVs, this is likely to increase.
There are several things to consider when evaluating the fire risks surrounding EV charging. The first is the charging system itself. EV chargers face the same fire risk as any electrical installation. Their safety and security depend in large part on the quality of the wiring and components, as well as the competency of the installer. This is especially the case in home chargers.
Improper or outdated wiring can short circuit, arc, and/or overheat, all of which can result in a fire. Furthermore, the ground fault circuit interrupters used in these installations also have a notoriously high failure rate, estimated to be 57%.[iii]
The makers of the charging equipment must conform to the National Electric Code which mandates they have their equipment certified by an independent agency such as Underwriters Laboratories (UL®). Additionally, they must install proper grounding and use monitoring equipment that can sense excessive temperature and shut the charging process down.[iv]
So, while these requirements will no doubt result in safer EV charging, electricity has a habit of finding ways to start fires.
The second risk involves the vehicle being charged. Many lithium-ion battery fires occur during charging because the cells overheat when there is a defect in the battery or in the battery management system. So, the large BESS in the EV also represents a fire risk that should not be ignored.
Any fire at an EV charging station has the potential to spread to the vehicle being charged. Vehicles represent a significant fire load that, when fully involved with fire, can easily spread to adjacent vehicles or structures as was dramatically shown in the video.
In the video, a significant fire developed that involved a total of three vehicles in under three minutes. Aside from the speed of the fire, the fire also was too large to extinguish by portable fire extinguishers as soon as it self-vented from the vehicle of origin. With NFPA setting the gold standard response time at four minutes for the first engine, some form of fire suppression must occur prior to the fire department’s arrival if a conflagration is to be avoided.
Finally, EV charging stations will be frequently coupled with small to medium sized energy storage systems (ESS). To accommodate a large demand for EV charging (having each station occupied and actively charging), ESS will be necessary to supplement direct grid electrical supply. When demand subsides (overnight for example), the ESS will recharge from the grid supply and be ready for the next peak in EV charging demand.
For more information on the fire risks associated with ESS facilities, see here.
Fortunately, fire suppression technology exists that can easily be installed in home and public EV charging stations and its associated infrastructure. The Stat-X® condensed aerosol system is ideal for these frequently unmanned EV charging stations.
The Stat-X system can be used as a stand-alone fire suppression unit that is activated when a preset temperature is reached on the unit. The units can also be designed in a system that is activated in a total-flooding manner when a fire detection system detects fire or the products of combustion.
The rapid response of the Stat-X system quickly suppresses fires while they are still manageable, thereby limiting damage and preventing uncontrolled fire spread. In enclosed spaces, the agent additionally remains suspended for up to twenty minutes to prevent reflash. Discharge of a Stat-X unit requires minimal cleanup.