Battery Energy Storage Systems (BESSs) have become more common across Washington state, though many are situated in high-fire-risk areas.
Li-ion Tamer and Stat-X preventative measures offer top-of-the-line protection from BESS fires. Both devices have been thoroughly UL tested and comply with NFPA standards; both detect off-gassing, thermal runaway and fire propagation in batteries. BESS fire suppression is often mandated by local fire districts for electric utility projects and is essential to prevent fires from spreading in remote areas.
Detection of Thermal Runaway
While lithium-ion remains the go-to technology for BESSs, work is underway to increase their battery chemistry options and expand energy storage systems’ options. While new types of batteries might have different properties than lithium-ion ones, any BESS design must include adequate safeguards against potential issues.
At a minimum, it’s crucial that all systems incorporate thermal management and fire suppression measures as part of their design; the physical layout must also prevent batteries from touching each other to minimize thermal runaway in a damaged cell that could otherwise spark a full-scale fire event.
As soon as this condition arises, chemical reactions in a battery cell electrolyte break down and heat is produced, leading to off-gassing that increases pressure in the cell and eventually leads to smoke being exhaled, signalling imminent explosion or fire.
Lithium-ion BESSs now boast advanced off-gas detection. The sensor’s purpose is to identify and warn of off-gassing before temperatures increase to the point where thermal runaway occurs and fire spreads further.
Other sensors are also available for monitoring other potential causes of catastrophic BESS failures, including Power Quality Sensors which detect electrical abuse as well as Refrigerant (R-134a) Gas sensors to detect leaks from battery cooling systems and shock and vibration sensors to alert operators to any mechanical abuse that can lead to battery fires or thermal runaway events. All these advanced sensors can be conveniently bracket-mounted inside BESS without taking up valuable floor space.
Detection of Smoke
Damaged cells within a BESS can quickly overheat, producing CO2, volatile organic compounds (VOCs) or other compounds (dependent upon battery chemistry), that become off-gasses that could ignite into fires if their levels reach critical thresholds; once ignited, thermal runaway may quickly spread across multiple cells in the system.
BESS fire protection systems must detect off-gasses as early as possible to limit thermal runaway and limit the risk of fire for nearby cells, equipment and the facility as a whole. That is why TSware offers monitoring sensors, an EMS system (BESS EMS) and a fire suppression system (Stage 3), all capable of detecting smoke caused by damaged batteries releasing their volatile gases that create off-gassing of smoke-causing substances that quickly escalate to thermal runaway.
When the TSware BESS monitoring system (which includes Power Quality Sensors, Coolant & Water Sensors and Shock & Vibration Sensors) detects an off-gas event, it triggers Stat-X’s fire suppression system to shut off batteries immediately and activate ventilation in order to clear away flammable gases that accumulate. In comparison with water-based systems that require costly installation with costly cylinder weighing and hydrostatic testing procedures for installation purposes, Stat-X can be quickly installed within either its battery enclosure or container for quick response time in case of fire outbreaks without incurring expensive damage to electrical/mechanical equipment.
Detection of Leaks
BESSs are generally ungrounded systems, in which all line conductors are intentionally disconnected from the ground. When one of these isolation points becomes faulty it can create an unsafe phase-to-phase or line-to-line short that could prove catastrophic, making it essential to identify and resolve initial fault conditions as quickly as possible. A DC-sensitive residual current monitoring system is employed here; such devices detect leakage currents within individual modules, packs and containers as well as optimise energy management by collecting data and using battery management systems (BMSs). Additionally, a battery management system (BMS) helps collect data for data management as well as optimize energy management.
At present, with more large-scale BESS projects entering the market, comprehensive safety systems are of vital importance in design. This involves segregating kilowatt groups into MAQ zones, understanding structural fire ratings, designing for limited egress in confined spaces and limited egress, securing fire marshal approval as well as installing an appropriate fire suppression system.
Effective fire suppression systems must not only deplete oxygen and extract heat from a fire but also prevent further spread to unburnt batteries. This may be achieved using multiple methods including directed spray application that targets specific threat areas or total flooding to cover an entire container or room. Regardless of which system is chosen, all must be reliable enough to return to service once a fire has been extinguished.
Detection of Fire
Battery Energy Storage Systems (BESSs) are large-scale reservoirs of electrical energy. The systems are installed within facilities and connected directly to the power grid, offering the potential to store electricity for later release into buildings or communities as needed, helping balance the load on the power grid, as well as providing power directly.
Fires pose a significant threat to a BESS and can quickly escalate, threatening both property and investment alike. Reliable fire prevention strategies are key to lowering total operating costs (TOC). Early warning sensors with clean suppression systems can detect threats at their earliest stages (Stages 1& 2) before they spread or cause more serious harm.
BESSs typically contain multiple lithium batteries connected by complex control and monitoring systems, and as such can contain numerous potential sources for fire hazards to arise from. A manufacturing defect or mechanical/electrical abuse could initiate a thermal runaway, an extremely dangerous chemical reaction which converts chemical energy to thermal energy that spreads throughout each cell in the BESS.
In the event that preventive measures fail and a BESS fire does start, Nobel’s comprehensive fire protection solution for BESS must be activated: Containment. This involves using industrial IoT smart sensor technology (Li-ion Tamer Gen 3), alarm & control panels, and notification & A/V appliances to implement containment measures. The primary course of action would be for Nobel’s BESS Battery Management System to shut off power to all batteries in order to limit their temperature increases below thermal runaway thresholds; additionally, this may involve ventilation activation to remove potentially flammable gases from the area.