Battery Energy Storage Sites: Safety Regulations

David Mundell Excerpts

Thursday 5th June 2025 Commons Chamber

[John Milne (Horsham) (LD)]

I beg to move,

That this House recognises the unique challenges posed by lithium-ion fires in battery energy storage sites; and calls on the Government to bring forward enforceable national regulations for their design and construction.

I have asked for this debate in order to highlight important issues associated with lithium-ion batteries when deployed at grid scale. These installations are known as battery energy storage systems, or BESSs. In particular, I am calling for clear national regulations that could be applied in the same way in every part of the UK. We need legislation, and I hope that this debate will push the Government further along the road to passing it.

The UK has set a target to achieve net zero emissions by 2050. To achieve that, many wind and solar farms have been constructed and permissions are being sought for many more. I fully support the drive towards renewable energy; the enhanced regulation that I am suggesting today is intended to secure the industry’s future, not to create more obstacles. I think it is perfectly possible to draw up regulations that will not stand in the way of BESS roll-out, and which in the long term could actually save the industry from a wholly avoidable setback in the event of an accident.

BESSs solve the classic question of what to do when the sun don’t shine and the wind don’t blow. They provide a number of highly useful functions, including load balancing, peak shaving and energy arbitrage. Above all, they make it practical to meet a much larger percentage of our national energy needs from renewables. However, every energy system carries some kind of risk, and most BESSs currently use lithium-ion battery technology. In the event of an accident—and sooner or later there are always accidents—lithium-ion batteries catch fire in a different way from other materials, in a process known as thermal runaway. It is important to note that most BESSs now rely on lithium iron phosphate or LFP batteries. This chemistry is much more stable than lithium nickel manganese cobalt oxide or NMC cells, which are common in consumer uses. That means fewer incidents, but those incidents can still be dangerous. In the future, there will undoubtedly be other chemistries, so we need to leave space for innovation.

Thermal runaway generates very high temperatures and requires different firefighting methods. It is usually best not to try to put out the fire, but rather to control the spread. Firefighters also have to contend with severely toxic gas emissions, the risk of an explosion, soil contamination and damage to watercourses. To repeat, I am in no way suggesting that battery energy storage systems are inherently unsafe. The risks they entail may be different from those of traditional systems, but they are perfectly controllable.

[David Mundell (Dumfriesshire, Clydesdale and Tweeddale) (Con)]

Does the hon. Gentleman share my concern that the location of many of these sites are in rural areas, which are often served primarily by retained firefighters? They are a long way from where specialist firefighting resources would come from, and that does not seem to be taken into account fully in the planning process.

[John Milne]

I appreciate the right hon. Gentleman’s intervention. I agree that such sites can be in remote locations where there are fewer resources. As I will say later in my remarks, fire officer training is very much part of what I am recommending.

There is a strong case for mandating water-based suppression systems, off-gas detection, ventilation systems and thermal runaway mitigation as design conditions. Unfortunately, that is far from the case today. The guidelines for planning approval are imprecise and vary across the devolved nations. Currently, the burden of responsibility falls on individual local authority planning officers who have no specific training or background in lithium-ion technology—and why on earth would they?

For reasons that are hard to understand—perhaps the Minister can explain—fire and rescue services have not been made statutory consultees for planning applications. The current guidance states that applicants are “encouraged to engage” rather than required to do so, but even compulsory consultation is not enough by itself because the fire services themselves do not always have the expertise. Within the last fortnight, Henry Griffin, Suffolk’s deputy chief fire officer asked for fire services to be given new powers, saying:

“I’d like to see a power that is akin to a regulatory order like those for a commercial property, where we would have the power to enforce safety measures on those sites.”

He explained that the fire service is currently just a “contributing partner”, able to give “direction and professional advice”, but not necessarily to require what it might like.

The result is inconsistency, which is destructive both of public trust and of the success of the industry. In my own constituency of Horsham, the local planning authority has rejected a BESS application, while a similar site, just half a mile away, across the border in Mid Sussex, has won approval. Such inconsistencies show alarming parallels with Grenfell. The Grenfell disaster was the end result of many failings by both individuals and companies, but at heart it was a failure of regulation. The rules left things wide open for exploitation by cost-cutting developers, which is exactly what happened. Just as with lithium-ion batteries, a new technology—in that case cladding—was being used at scale for the first time, without proper understanding of the risks. The time to act is now because the number of BESS applications is expanding exponentially.