BESS Technology

The fire safety of Battery Energy Storage Systems (BESS) has become a growing concern due to around 70 fire-related incidents since 2012, 60 since 2018 [BESS Failure Event Database]

The rapid expansion of BESS projects and the supporting industry has led to an increase in concerns, as the occurrence of fire incidents has also escalated. BESS fires can pose a significant safety risk to the area surrounding the BESS installation, posing a human safety risk from the fire and products of the fire and a risk to the environment.

Whilst safer than some other forms of Lithium Ion battery, Lithium Iron Phosphate batteries (LFP) can and do ignite and are subject to thermal runaway. LFP Battery fires not only pose a risk through the fire itself and the challenges of containing/extinguishing, but also the production of toxic gases, including carbon monoxide (CO) and hydrogen fluoride (HF)(Liu, P., et al., 2020. Thermal runaway and fire behaviors of lithium iron phosphate battery induced by over-heating. Journal of Energy Storage, 31, p.101714.)

The Trina Solar UK Holdco Ltd Planning Statement for the proposed Frome Power - Energy Storage Facility, provides a general description of the fire detection and fire prevention equipment to be installed, although the loose reference to meeting international standards is less than adequate.Smoke detection and inert gas fire suppression mechanisms are not currently deemed best practice and there is no information on how reliably these would operate in the event of fire - particularly a thermal runaway that in one cell, leading to a domino effect within the battery, potentially leading to explosion. As the battery size increases, the likelihood of a more severe fire also rises. In the event that a battery fire is extinguished, there are still significant potential hazards, including secondary fire, deflagration and toxic gas release. Therefore, it is essential to implement a secondary fire extinguishing system and closely monitor for any rekindling - this is not described in the Planning Statement.

As planning regulations and practice is relatively slow to catch up with technological developments, it seems clear that there is a lack of effective guidance for planning authorities on large-scale BESS developments.

Similarly, it would appear as though safety legislation and practice also needs to catch up. “Safety of Grid Scale Lithium-ion Battery Energy Storage Systems” Fordhamet al., 2021.

UK Government guidance on Battery Energy Storage Systems

The following is copied from the the UK government website's Renewable and low carbon energy guidance section on Battery Energy Storage Systems:

Electricity storage can enable us to use energy more flexibly and de-carbonise our energy system cost-effectively - for example, by helping to balance the system at lower cost, maximising the usable output from intermittent low carbon generation (e.g. solar and wind), and deferring or avoiding the need for costly network upgrades and new generation capacity.

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What is the planning application process for battery energy storage systems?

When applying for planning permission for development involving lithium-ion battery energy storage systems these are subject to the requirements set out in The Town and Country Planning (Development Management Procedure) (England) Order 2015.

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What can applicants seeking planning permission for battery energy storage systems do to ensure they consider any potential risks?

Where planning permission is being sought for development of battery energy storage systems of 1 MWh or over, and excluding where battery energy storage systems are associated with a residential dwelling, applicants are encouraged to engage with the relevant local fire and rescue service before submitting an application to the local planning authority. This is so matters relating to the siting and location of battery energy storage systems, in particular in the event of an incident, prevention of the impact of thermal runway, and emergency services access can be considered before an application is made.

Applicants are also encouraged to consider guidance produced by the National Fire Chiefs Council (PDF, 488 KB) when preparing the application.

The location of such sites are of particular interest to fire and rescue services; who will seek to obtain details of the design, and firefighting access and facilities at these sites in their register of site specific risks that they maintain for the purposes of Section 7 of the Fire and Rescue Services Act 2004.

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What can local planning authorities do to ensure they consider any potential risks when determining the planning application?

When planning applications for the development of battery energy storage systems of 1 MWh or over, and excluding where battery energy storage systems are associated with a residential dwelling, are submitted to a local planning authority, the local planning authority are encouraged to consult with their local fire and rescue service as part of the formal period of public consultation prior to deciding the planning application. This is to ensure that the fire and rescue service are given the opportunity to provide their views on the application to identify the potential mitigations which could be put in place in the event of an incident, and so these views can be taken into account when determining the application.

Local planning authorities are also encouraged to consider guidance produced by the National Fire Chiefs Council (PDF, 488 KB) when determining the application.

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