Mega-batteries in the electricity system, industry and in our homes are on the way, and that will throw up challenges when it comes to fire safety. In the USA, development is more advanced, and the work on managing the risks is in full swing.
Our energy system will be transformed in the years to come. Sustainable energy will become more prominent and the storage of surplus energy from wind turbines and solar cells will be an important part of the solution. Therefore, Energy Storage Systems (ESS) will play a pivotal role, both in the general infrastructure, in industry and even in domestic homes. Development is gradually getting underway around the world, but if you look at the USA, it is in full swing, with ESS being constructed on a large scale.
However, it will entail a number of fire safety challenges when you install large-scale batteries with all the chemicals and energy volumes they contain.
- In Denmark, we are sniffing around the area, for example, in connection with solar farms, in large companies and in data centres. However, the technology entails a number of challenges in terms of fire safety. In a fire, the batteries can emit flammable gases, or ‘thermal runaway’ can occur, whereby the battery generates heat uncontrollably with the result that the battery cells can self-combust. When an entire room is filled with batteries, this poses a risk that has to be managed, says Mikael N. Gam, who is a fire safety consultant with DBI – the Danish Institute of Fire & Security Technology.
New standards in the pipeline
Even though the prevalence is greater in the USA, the technology is also fairly new there. There are standards in the field but they are currently being revised thoroughly due to the experiences gleaned in recent years.
- There are new and relatively prescriptive standards on the way which must describe what you need to do to ensure an acceptable level of fire safety according to American standards. This will change, for example, when an ESS is covered by the standard based on the type of battery technology and the volume of energy in the batteries. As far as possible, the standards will also cover future technologies so that unregulated technologies cannot emerge, even though the field is developing rapidly, says Mikael N. Gam.
In addition, there will be limitations to the energy capacity (probably a maximum of 50 kW) in every block in an ESS and minimum distance requirements between the blocks and between a block and the walls, if the system is installed in a building. This way, you are minimising the risk of a fire spreading unhindered in a really large ESS. There are solutions available up to 30,000 kW, and it is expected that this will increase further in the coming years.
- At the same time, in the drafts of the new standards the scene is now set for requirements for sprinkler systems, for which there is a strong tradition in the USA, explains Mikael N. Gam.
What about the emergency response teams?
It is not only in relation to standards that ESS is being looked at in more depth in the USA. Full-scale tests of various ESS systems are being carried out in order to gain more knowledge on how batteries react in a fire when ‘thermal runaway’ occurs, what effect the batteries have in terms of heat in a fire, how fire spreads between the battery blocks, which gases are created and what can be used to extinguish them.
The last point is particularly crucial as some batteries, for example, can flare up again days or weeks after they have been extinguished and because different battery technologies require different extinguishing methods. For example, it is possible to extinguish a lithium-ion battery with water. But, if you pour water on a lithium battery it can create hydrogen, which is extremely flammable.
- Another aspect that is being focused on is the training of emergency response teams so that they can deliver an effective response. This is made more difficult by the fact that different ESS systems require different responses and that the technology is developing at such a rapid pace that standards can't keep up. This also makes it difficult for emergency response teams to keep up, says Mikael N. Gam.
The work on fire-testing ESS systems and finding a solution to the training of emergency response teams continues apace in the USA. And, there is good reason to keep abreast of the solutions they come up with on the other side of the Atlantic. Because even if the prevalence of ESS is still limited on these shores, it is on its way.