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Cleve Hill - The Continuing Story

By Richard Fleury

The world’s biggest battery – and the danger to Faversham – just doubled in size.

In the last issue, we reported on the threat to life posed by plans to install the largest battery plant ever built on the proposed solar power station on Graveney marshes.

We can now reveal it will be TWICE the size. With its capacity ballooning from 350 to 700 MWH, the Cleve Hill mega-battery is now more than five times the size of the current world record holder in Australia.

The developer’s ambitions fly in the face of safety warnings from around the world. The lithium ion battery will be housed in 120 metal shipping containers – each one a ‘bomb’, according to a respected physics professor.

Based on industry experience both in the US and South Korea, the odds are that at least one of these containers will catch fire. And as our investigation in the last issue of the Faversham Eye showed, li-ion battery fires can spread in a catastrophic chain reaction called thermal runaway, creating clouds of highly toxic hydrogen fluoride (HF) gas.

South Korea ordered a nationwide probe following blazes ar 23 battery storage facilities

Cleve Hill Solar Park Ltd, the company behind the project, is doubling down just months before the planning inspectors’ 30 November deadline. The fate of Graveney marshes and surrounding areas then lies with the Secretary of State for Business (Andrea Leadsom, at the time of writing).

CHSP quietly announced the dramatic news in September, at a planning hearing in Teynham to discuss the battery. Despite being completely untested at this vast scale, the controversial technology was not initially on the inspectors’ agenda. The hearing was scheduled only at the request of the Faversham Society.

“It’s only as a result of us battering away, saying this has to be raised. It hadn’t been dealt with,” says the Faversham Society’s vice chairman Sir David Melville.

CHSP sent 15 people, twice the number at any previous hearing, even jetting in staff from its Swiss battery supplier Leclanché from Geneva for half a day.

Physics professor Sir David was not impressed. “Who would you bring along to vouch for the safety of one of your operations?” he says. “The manufacturer of that equipment? It’s risible. They should have had someone from the Health and Safety Executive.”

Leclanché told inspectors its Graveney BESS (Battery Energy Storage System) would comprise 120 steel containers, each packed with 6 MWH of lithium ion batteries, claiming: “If each unit is made safe, it doesn’t matter how big the overall plant is”.

CHSP calls the project ‘pioneering’; PR-speak for an experiment. No battery installation of this scale has ever been attempted anywhere in the world before, let alone operated safely. Yet despite frequent, well documented fires and explosions associated with li ion batteries globally, CHSP insists its scheme is risk-free.

Leclanché vice-president Daniel Foehr admitted to inspectors: “The size of this project would be larger than anyone has experienced.” But, he said: “We don’t see this as one large installation. It’s a scaling up of an installation. For us it doesn’t make a big difference if we are dealing with 20 enclosures or 100 enclosures as we apply the same safety standards on each enclosure.”

Is it really possible to scale up this flawed technology without scaling up the risks? Sir David Melville certainly doesn’t think so. “It’s a fatuous argument, that it’s no more risky to have a hundred batteries than one,” he says.

Sir David, a distinguished academic (whose CV includes working for NASA on the Apollo 11 moon landings early in his career) believes each 40ft metal container is a potential bomb. “Bombs work by containing the pressures resulting from rapid combustion,” he explains. “That’s what a bomb is, when the metal casing gives way, which is very likely.

” At the hearing, Leclanché’s Daniel Foehr stated: “The fire suppression system inside container will close down fire and not propagate to the whole enclosure.”

To be clear, absolutely no evidence exists to support this claim. Currently there is no publicly available data proving that suppression systems such as sprinklers and extinguishers – so called ‘active fire protection’ – can completely prevent or control thermal runaway. Suppression doesn’t penetrate a battery’s cells, so the heat inside cannot be absorbed or dissipated. It can easily appear that the fire is out, but the heat is actually trapped inside a cell, which can produce enough heat to ignites neighbouring cells, triggering thermal runaway.

Leclanché spokesman Foehr further claimed that spacing containers three metres apart will prevent fire spreading between them. “With these safety distances, it can not propagate to the neighbouring one,” he said. “From 1 MWH to 1 GWH you can scale up according to safety rules and guarantee there is no fire risk.”

Nonsense, says Sir David. “Look at the Great Fire of London,’ he argues. “Once you have a decent sized fire, then it will spread over distances of tens of metres.”

At the hearing he asked: “There have been runaway fires. Did these precautions not exist?”

BESS fires continue to flare up around the world with alarming frequency. Fires linked to lithium ion batteries have struck Europe, the US, Australia and Asia. In South Korea alone, fires have struck 23 of the country’s 1,490 battery storage installations since 2017. That’s three fires per 200 sites. In response, the Korean government suspended operations at 522 facilities and launched a five month official investigation which concluded in June this year. But more about that later.

Leclanché’s Daniel Foehr answered: “These incidents have been a paradigm shift in lithium ion industry. The Korean government investigated those manufacturers. Manufacturers redid a lot of their design and harsher regulations brought in improved design with early detection systems within the enclosures, monitoring and automatic shutdown in the event of a fire. This makes the systems way, way more reliable than two years ago.”

Only this year, an exploding li-ion battery container at an Arizona solar power plant hospitalized four firefighters with chemical and chemical-inhalation burns. The container included a built-in alarm and a self-activating fire-suppression system.

The accident, in April 2019, prompted an Arizona state energy industry regulator to brand the risks ‘unacceptable’. It was the second fire suffered at an Arizona battery facility. The first, in 2012, was caused by a battery cell being overcharged due to a failure of the energy storage management system. Lightning struck for the second time despite the li ion batteries with 2 MWH capacity (a third of Cleve Hill’s planned 6 MWH per container) being housed in an industry-standard metal enclosure. Equipped with the same kind of safety systems CHSP proposes for its Graveney mega-battery. The container was designed to withstand significant heat and pressure and the interior was climate-controlled to keep the batteries at a safe temperature.

Following an inquiry into the fires, Arizona energy regulator, Commissioner Sandra D. Kennedy concluded in August that lithium ion batteries – specifically those that release hydrogen fluoride – “are not prudent and create unacceptable risks”.

The Arizona Power Service’s system supplier Fluence, is among the top US energy storage companies, with a clean, ten-year track record of building and operating 760 MWH of large-scale batteries.

In contrast, Leclanché has installed just 150 MWH. It’s largest BESS to date is 34 MWH. If it’s approved, Cleve Hill represents more than four times the total capacity the company has ever installed.

“Everything they’ve built so far is a fraction of this,” says Sir David Melville.

Leclanché s project manager for the world’s biggest battery installation is James Naish. James graduated with an engineering degree from Northumbria Uni a little over a year ago. Before being hired, his employment experience was largely limited to bar work and helping out on his family’s farm.

But returning to South Korea, let’s take a closer look at the ‘paradigm shift’ Leclanché claims has occurred within the li -on storage industry ‘over the last two years’. The Korean government’s findings on battery facility fires were only released in June this year. The report blamed four factors: poor grounding causing electrical shocks, bad contractor installation, a lack of integrated control and protection systems and ‘insufficient management of the operation environment’. It found that fires were more likely in certain environments, notably coastal sites, which caused humidity and salt damage to equipment. Of the 23 installations that caught fire, 18 were in coastal or mountain areas.

The proposed Cleve Hill site is low lying marshland, on a flood plain just metres from the sea.

“Battery manufacturers, system integrator companies and power conversion system companies are all at fault,” said Kim Jung-hoon, the electrical engineering professor heading the investigation panel.

Battery cell defects were found, but testing didn’t result in fires. So do li-ion batteries explode? In 2017 battery fire safety study by Norway based DNV GL, a leading independent advisor to the renewable industry. Despite conducting hundreds of ‘abuse rests’ on cells, none exploded. But researchers found that battery cells exposed to heat released flammable gases. “The explosion hazard is not the battery itself, but the gases it may generate,” the report concluded.

Either way, the energy industry is being forced to acknowledge that fires linked to l-ion batteries occur with disturbing regularity.

“Li-ion batteries can burn,” said Ben Ditch, a fire researcher at FM Global, an American insurance company specializing in loss prevention for global corporations. “The fact is the hazard exists. It is something a lot of us have been worried about for some time.”

The spectre of disaster looms large within the battery storage industry. Global industrial consultants and analysts Wood Mackenzie tracks the safety of 200 battery storage systems in the US with a capacity of 10 MWH or more. The two Arizona fires plus another at the S&C Electric Company’s testing facility where li ion batteries were the suspected cause put the ratio of fires to batteries at two or three out of 200 – exactly the same as in South Korea. At those odds, it is almost inevitable that one of Cleve Hill’s 120 containers will catch fire.

“That’s one percent,” says Sir David Melville. “So with more than 50 percent certainty you are going to have one fire. And one fire could cause the runaway! Small scale fires are containable. But if you have got hundreds of containers together, it’s a different kettle of fish.”

Wood Mackenzie’s energy storage research director Ravi Manghani has said: “The ratio has to go down at least an order of magnitude, if not more,” adding: “The industry needs to do a better job of manufacturing safer cells, designing systems that have sufficient levels of redundancy, and having real-time monitoring that engages predictive analytics.”

UL LLC – formerly Underwriters Laboratories – is a 125-year old global product safety certification company with offices in 46 countries. Its principal engineer Ken Boyce said in an interview: “Li-ion battery cells fail at a rate of only around one in every 12 million. Unfortunately, with billions of cells now being installed each year, that means something is going to happen.”

Something is going to happen. And the odds are it will happen to the what is by far the biggest li-ion battery the planet has ever seen.

So who, if anyone, will insure an experimental, untested power station built in one of the UK’s most densely populated counties, on a flood-prone site between two towns of 20,000 and 32,000 people and a city of 55,000?

The answer is nobody... yet. At the recent planning hearing CHSP admitted: “We don’t have an insurer on board yet, it’s a bit premature for that, but we are in discussion with them,” said the company’s lawyer Gareth Phillips, adding: “It’s a fairly obvious point that there’s no way we’re going to proceed without insurance because it would be a huge risk if something goes wrong, so insurance would have to be in place before construction went ahead anyway.”

If something goes wrong, or when? Much of the research carried out into the risks of li-ion battery storage is done by manufacturers and utility companies themselves, with test results kept secret. Inevitably, that puts local residents researching the risk to their community at an impossible disadvantage.

In our last issue, we reported on gas dispersal modelling carried out by biochemical engineer Dr Bruno Erasin, who lives near the site. In response, CSHP commissioned its own report from consultants Arcus. Perhaps unsurprisingly, it concludes that a battery fire in one container where suppression equipment has failed would not release enough HF gas to poison those living nearby.

Wind dispersal patterns - In a key experiment in the Nevada desert in 1986, acid was released forming a dense, ground-hugging cloud of deadly hydrogen fluoride, the gas produced in li-ion battery fires. Two miles downwind and depending on the wind direction the toxic cloud takes in the edge of Faversham. The cloud will have more than twice the lethal concentration of gas. As it travels beyond the town it will dilute causing blindness and life long injuries. For a full explanation of the possible risks of a fire at the battery park (see Issue 5)

“They’re throwing a lot of money at this.” says Sir David Melville. “I’ve gone through Bruno’s calculations really thoroughly and they’re very sound, using well-established models. And their stuff is a different model, by a consultancy working in this area.”

Since our report in the last issue, CHSP has finally contacted Kent Fire and Rescue Service, outlining the company’s plans for managing a fire and is awaiting a response. For firefighters, li-ion battery fires are hazardous, intense and difficult to control. Even relatively small fires can take days or even weeks to extinguish and can appear fully extinguished when they are not. Dumped household li ion batteries were blamed for setting 300 tonnes of refuse on fire in Scotland earlier this year. Forty firefighters and six fire trucks were needed to fight the two-day fire at a waste site in Dunbar in January. Afterwards recycling company Viridor warned a damaged li ion battery can ‘project a shaft of flame for several minutes and can ignite surrounding waste material’.

According to UK waste management trade body the Environmental Services Association (ESA), a quarter of the 510 fires reported by ESA members across the UK in 2017-18 were attributed to discarded li-ion batteries.

Li-ion batteries continue to be linked to catastrophic fires, both overseas and here in the UK. Charging batteries are suspected of triggering the recent blaze which sank the Californian dive boat Conception, claiming 34 lives. The £100 million fire which destroyed Ocado’s automated warehouse in Andover earlier this year began when a li ion powered robot caught fire while charging.

Meanwhile, the number of battery fires on aircraft continues to rise. In the US, the Federal Aviation Administration has said: “FAA battery fire testing has highlighted the potential risk of a catastrophic aircraft loss due to damage resulting from a lithium battery fire or explosion.” Leading US aviation safety consultant John Cox describes lithium-ion battery fires as “one of the few rising risks in aviation”. And as recently as July this year, a Virgin Atlantic Airbus with 217 passengers on board was forced to make an emergency landing during a New York to London flight after a passenger’s battery pack caught fire.

The energy companies behind the Cleve Hill venture – Hive Energy and German-owned Wirsol – are guaranteed to make many tens of millions a year trading on the energy market with their monster battery. So it should be no surprise that they are willing to gamble that nothing will go disastrously wrong.

Their assurances may ring frighteningly hollow to those of us living in its shadow, but we are not the people they need to convince; it’s the planning inspectors, Andrea Leadsom MP and, let’s not forget, the insurance industry.

In the end it may not be the loss of a unique and bleakly beautiful landscape and its wildlife, the prospect of lasting environmental damage or even the potential loss of human life that pulls the plug on this nightmarish industrial experiment but simply the reluctance of underwriters to take a punt on such deeply unpromising odds.


A plan by Faversham MP Helen Whately to debate the proposed solar power plant in the House of Commons on 9 September was scuppered by Prime Minister (at the time of writing) Boris Johnson’s unlawful proroguing of Parliament. Ms Whately opposes the scheme on enviornmental grounds but has remained silent on the battery issue. Instead, 50 local campaigners travelled to Westminster to meet Environment Minister Zac Goldsmith as part of a visit by the Graveney Rural Environment Action Team (GREAT).


Faversham-based Richard Fleury has been a journalist for 30 years, writing for national newspapers and magazines including BBC Top Gear, Arena, GQ, Wired, the Times and Sunday Times and the Guardian.


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