Thursday, April 11, 2024

Protecting energy storage from fire risk

Kristoffer Eldin

As global government’s push towards ambitious sustainability targets, the energy storage market is expanding rapidly. To keep pace with rising demand, between 2022 and 2030, it’s estimated an additional 387GW/1, 143GWh of energy storage is needed globally. That’s more than Japan’s entire capacity for 2020.

With more energy being stored globally, more batteries are regularly being used to higher capacities. That brings about significant fire risks, and many are seeking stronger reassurance on safety as the market continues to expand.

Kristoffer Eldin, managing director, Dafo Energy Storage Protection, unpicks the risks associated with increased battery storage globally and discusses how to mitigate these to ensure a safe transition to a sustainable future.

A changing energy landscape

A key part of global environmental targets is the shift to net zero emissions by 2050, and as businesses and individual drive towards low carbon targets, global reliance on electricity is skyrocketing.

The resulting ‘electrification’ (both domestically and commercially) is evidently already having a positive impact on global carbon emissions. It’s also seeing an increase the number of batteries (predominately lithium-ion (li-ion) batteries) needed to store and distribute the clean energy. This brings about new fire safety risks, which are evidenced in many recent battery fires at energy storage facilities.

Unpicking the risks…

For li-ion batteries, the primary risk is thermal runaway; a process initiated by a battery cell malfunction. That malfunction can occur as a result of overcharging, overvoltage, physical damage, mechanical failure or overheating.

In thermal runaway, a battery experiences extreme temperature increases, which prompts the battery to release excess energy, causing further temperature increases. If those temperatures aren’t controlled quickly, the battery can be at risk of fire, toxic gas emissions and even large explosions.

With energy storage facilities, as batteries are often stored in close proximity, the risk is amplified, as thermal runaway can spread across batteries.

A distinct lack of regulation

Disappointingly, there’s a lag in mandatory guidance around battery fire safety at energy storage facilities, with many government and insurer conversations around the issue still in relatively early stages.

Although there are some optional standards, safety decisions ultimately rest with owners and operators. Unfortunately, that means it often comes down to price. However, there is an important cost trade-off between:

  • Opting for a cheaper solution that isn’t necessarily fit for purpose and the extensive costs once the risk is realised and not effectively mitigated
  • Selecting the right solution, ensuring safety from the outset.

Out with the old, in with the new… or not?

With electric powering so much of our daily lives, there’s a growing presence of scrap batteries in everyday waste streams. Subject to the same risks, on an arguably larger scale due to the harsh waste processing streams, these batteries need to be identified, stored and handled carefully to minimise risk.

The presence of batteries in manufacturing processes is also increasing, and scrap batteries can be produced on a large scale before being discarded. For example, should a car manufacturer experience issues with a battery (post mass-manufacture), they will likely switch this out in the final model for a new battery. The resulting scrap batteries – in mass – are subject to the same battery risks, and they will need to be stored carefully before they’re repurposed for use in new components or car models.

Overcoming risks to enable a safe, green future

In thermal runaway, li-ion batteries are able to produce their own source of oxygen, which can self-sustain fires from within. This makes suppression using traditional measures particularly challenging.

Research suggests large quantities of water, applied for extensive periods of time, is the most effective suppression solution for li-ion battery fires. However, this is time consuming, expensive and in direct contrast with the environmental initiatives that are leading the new energy revolution.

To suppress thermal runaway risk sustainably and effectively, extensive research – carried out by Dafo Vehicle Fire Protection and Research Institutes of Sweden – points to an early fire warning system, supported by immediate spot cooling. This needs to detect potential battery failures ahead of temperature increases, preventing thermal runaway from progressing. That system should be built inside the energy rack to control temperatures and risk from within the battery, containing and minimising risk.

Temperature development with suppression system either at venting or thermal runaway.
 Tests conducted at RISE by Dafo VFP.

A risk destined to grow

Inevitably, as demand for sustainable energy continues to increase, the risks brought about by li-ion batteries will only become more prevalent.

Of course, the switch to sustainable energy is critical for our future, but doing so safely is essential.

To find out more, visit Dafo’s Energy Storage Protection.

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