Five Myths and Misconceptions Around BESS & Lithium Battery Safety

Driven primarily by concerns about climate change and resource availability, the demand for renewable and sustainable forms of energy has soared. But intermittency in sectors like wind and solar power — a disruption caused by the inconsistency of the weather — has made them less reliable as forms of energy. These limitations, however, have been primarily offset by the use of Battery Energy Storage Systems (BESS), a means of storing the energy produced until it is needed.

Lithium-ion (Li-ion) batteries have long been the most common type of battery used in BESS, offering numerous advantages such as size and power density, making them affordable and versatile as a means of storage. However, these batteries aren't perfect; they can fail, so it's essential to understand what's true and what isn't about lithium-ion batteries and the systems they make up.

Myth #1:?There are standards that risk managers and facilities managers can use to guide them toward creating policies and processes.

Though standards like the National Fire Protection Association 855 (NFPA 855) have been published and continue to be refined, there are fewer standards and forms of guidance regarding Energy Storage Systems compared to other industries. With interest in BESS steadily increasing and the decrease in lithium-ion battery prices, standards are being quickly created and revised. However, the BESS industry is still in its infancy, and policy creation is ongoing. For this reason, working with risk engineering organizations is especially important to develop safe processes and risk assessments for your facility.

Myth #2: Failure rates of BESS at battery storage facilities are well-known and published.

Currently, the communication of data on the state of failure rate research could be better. Publicly available data on BESS reliability is limited and inconsistent, and much of the recorded information was collected in highly controlled and fixed conditions. Due to the variability of real-world use, this data can be unhelpful in determining actual risk. Furthermore, there isn’t yet any consensus on how to present data, making combining or evaluating datasets challenging. Fortunately, research is progressing significantly, and public data storage platforms are providing familiar and easily navigable locations to find and share data. Some well-known platforms include the Battery Archive and the National Renewable Energy Laboratory.

Myth #3: Lithium-ion fires are similar to other industrial fires and don't require specific planning.

An important concept when talking about lithium-ion batteries and their associated risks is "thermal runaway." Physical damage to a lithium-ion battery cell, degradation due to extreme temperatures, ageing, or poor battery maintenance are among the many potential causes of thermal runaway. Once triggered, thermal runaway is a chain reaction within the battery that leads to an uncontrollable, self-heating state that can result in a violent ejection of gas, shrapnel, smoke, fire, and the potential for deflagration/explosion. Although any industrial fire is bad, lithium-ion battery fires are especially dangerous and possess unique attributes that make them very difficult to extinguish.?However, if they are extinguished, they are prone to reignition that could result in deflagration and injury to personnel or emergency responders in their vicinity. ?Current guidance for responders is to maintain a safe distance and focus their efforts on cooling adjacent units where possible, and to let the fire run its course.

The existing fire mitigation technologies may be able to supress the battery fire but fail to cool the batteries at the cell level to prevent thermal runaway propagation. In that context, we do not yet have a ‘silver bullet’ fire mitigation solution for Li-ion batteries. Currently, water-based fire mitigation, with its known disadvantages, is still being considered the best bet to supress battery fires due to its superior cooling properties, low cost, and availability. A multi-layered strategy which includes early detection and fire suppression specific to battery configuration, application, and location needs to be developed and reviewed on a case-by- case basis.

Read on to debunk Myths 4 and 5!