On the 28th May 2020, the proposal for the UK’s biggest solar farm was approved. For those ecologically minded, this seems like a huge win, a step in the right direction for sustainable development. However, on closer inspection, the questionable financial motivations, potentially catastrophic health risks, opposition from local communities, and impact on endangered ecosystems that this solar farm entails, puts a dampener on any potential progress towards green energy.
Surprisingly, local environmentalist groups have come out in opposition of the solar farm, with the Kent Wildlife Trust, Swale Green Party branch, The Countryside Charity (CPRE), Natural England, and the RSPB, all making public statements in resistance to the decision, after a long fought battle against the contractors for the past few years. The scientific arguments behind this oppositional consensus are two-fold, firstly stemming from the unsafe reputation of the batteries being used to store the energy, as well as the many destructive ecological consequences.
This project will be by far the largest solar farm in the UK and will cover almost five million square metres (900 acres) of marsh and fields. The largest solar farm in America is the ‘Topaz & Desert Sunlight farm’ at 4,700 acres; when you consider that the US is 40x larger than the UK, the fact we will have a solar farm only ~5x smaller than their largest, puts into perspective how truly enormous this project is. It will be the biggest solar farm in the UK, and the biggest battery in the world.
But why does this matter, surely the bigger the better, to serve the needs of our ever-growing population? With a power source this large, the batteries needed to store this energy come with their own host of problems.
A Battery Energy Storage System (BESS) of this size has never before been approved close to a highly populated area. The largest BESS was built in 2017 by companies Tesla and Neoen, in a remote region of Southern Australia, 10 miles away from the nearest settlement, and holds up to 185 megawatts of electricity. The BESS approved to store the energy produced at Cleve Hill will hold 350MW and will be located half a mile away from a village of 600 people and a primary school. Of course, this wouldn’t be an issue if these battery storage stations were completely safe.
The majority of BESS are made from lithium-ion batteries, which are popular in many household items (such as smartphones), because they’re light-weight, efficient, and don’t contain poisonous elements like lead, mercury, and cadmium, meaning they are ‘safe for landfill’.
However, they are also notorious for catching fire.
If a lithium-ion battery defects or overheats, it easily catches fires, that spreads through a process called ‘thermal runaway’, which is a type of positive feedback loop; essentially, it’s a cycle in which excessive heat keeps creating more heat, and there is no way for it to dissipate, and this runaway passes very easily from battery to battery. This means that any fault in a single battery, causes an unstable chemical reaction, which is small at first, but spreads easily, quickly, and exponentially. In a recent experiment the temperature between battery cells went from 220°C to 687°C in seconds. These runaway reactions can occur from high temperatures, damage to the battery casing, short circuits, and submersion in water, as metallic lithium has an exothermic reaction with water (their chemical contact creates heat).
Because of this, other solar farms of this size have been built in arid, desert zones, with very low population densities. Cleve Hill solar park is being built on marsh lands next to the sea, which is an area of frequent flooding, positioned between Faversham, Whitstable, Canterbury, and surrounding villages, totalling a population of approximately 100,000.
This is significant because, in a hypothetical situation where a single cell is slightly damaged, or if some of the battery station became flooded by the sea, an area the size of 80,000m2 (20 acres) could go up in flames within a minute. This area at sea level is a high flood risk, and often the sea will break over the wall, creating a floodplain. Due to this obvious risk, written into the Cleve Hill planning permissions, there will need to be a 5.5m high wall surrounding the batteries, and the electrical transformers (devices that transfer energy from one electrical circuit to another) are being made with in-built floatation capabilities. These requirements clearly show that the developers are aware of the flood risk to this area, and the hazards of lithium and water mixing.
There is not necessarily a risk of the fire spreading to the near population centres, due to the wet marsh land, and being surrounded by 13ft (5m) metal solar panels on all sides, which are not effective for fire spreading.
Rather, the main risk of a lithium-ion battery explosion is the gases produced as a by-product. Metallic lithium in these batteries chemically reacts with water, and produces a number of by-products: lithium hydroxide, hydrogen fluoride, phosphoryl fluoride, pure hydrogen, and many others.
Hydrogen is not inherently harmful, but is extremely flammable, and can cause massive explosions; if you hold a match up to a 1cm wide soap bubble filled with pure hydrogen gas, the explosion will be so extreme that you need ear protection. Hydrogen in the air has a flammability score of 20-60%, in comparison with petrol in the air, which has a rating of 1.5 – 7% flammability. The release of hydrogen is what gives lithium-ion fires their distinctive quality of burning for days or weeks at a time.
So, one of the by-products of a lithium-ion chemical fire is a flammable element which will further exacerbate fire, but what else will be released?
Lithium hydroxide, hydrogen fluoride, and phosphoryl fluoride all have the potential to be extremely dangerous gases.
Lithium hydroxide is a direct chemical combination of lithium and water (hydrogen + oxygen = hydroxide) and is classed as corrosive and acutely toxic, either through inhalation, swallowing, or on the surface of the skin. An excerpt from the official Emergency Response Guidebook, which identifies Hazardous Materials & Emergency Procedures, says “inhalation, ingestion or skin contact with material (LiOH) may cause severe injury or death”, due to burns and corrosion of tissue.
The other key group in question is the fluorine gases (hydrogen fluoride and phosphoryl fluoride), the effects of which are particularly severe. Even a diluted exposure to fluorine can be absorbed quickly into the skin and will cause deep burns if not treated within a few hours, and can even be fatal, if too much tissue is affected, leading to necrosis and corrosion of huge portions of the body. If droplets are inhaled or swallowed, this causes massive damage to the internal organs, and if not immediately fatal, leaves long-term damage on the body, such as lung disease, blindness, loss of limbs, and severe scarring.
In any case, the advice from all poison control centres is that if contact with fluorine is suspected, the patient must immediately remove themselves from the affected area, cut off all clothes, and wash their whole body with lots of clean water. How possible would this be if the entire village of Graveney was covered in fluorine gas within minutes, due to a battery explosion next to the sea? Current estimates say that, depending on direction, a 23mph wind would carry the toxic cloud to Graveney within a minute, Faversham within 9 minutes. Is this enough time to prepare these population centres for what is essentially a chemical warfare weapon?
The companies behind Cleve Hill claimed that they have made prior arrangements with the Kent Fire and Rescue Service, to ensure that the plans were safe, and any future emergencies would be manageable. But when asked, KFRS released this in an official statement saying that they “at no stage agreed to or signed off any plans relating to the project”.
It may sound like an outlandish accusation that these batteries are such a catastrophic risk, but we only need to look at the past evidence of lithium-ion batteries in action to substantiate these claims. On a much smaller scale, batteries of this type have exploded in laptops, hoverboards, and mobile phones, often causing severe burns and house fires, and billions in profit was lost due to extensive recall of dangerous products; hundreds of recycling plants have experienced fires due to consumers disposing of lithium-ion batteries incorrectly; South Korean electronics factories have faced explosions and fluorine gas exposure, causing many deaths; a California Robotics lab suffered a battery explosion which reignited 5 separate times, despite continuous extinguishing.
If the worst case should occur, and a battery fire takes hold, thousands of people would be affected by lithium hydroxide and fluorine gas exposure, and as explained in the figure (right), this could potentially lead to many hundreds of fatalities, with the below 5’s and elderly being at extremely high risk of death.
It goes without saying that the danger to human health of these batteries is extremely significant, but all other organisms in the area could be effected to the same level, with the potential to poison thousands of birds, mammals, and sea life within a huge radius.
It is not only the batteries which threaten the local wildlife, however. The developers claim that the solar park will deliver a 65% increase in biodiversity, compared with the current state of the land. However, their estimates where built on the species counts from farmed fields, which comprises some of the land that the solar farm will cover, and does not take into account the marshland areas which will also be replaced by 5m tall solar panels.
The arrangement of the panels is 16ft off the ground to mitigate the flood risk and will use an east-west orientation, because they can generate 44% more electricity than the same site with south-orientated panels.
These features of the solar array ensure that as little sunlight as possible will reach the earth underneath the panels, as this would be a waste of potential energy. The consequence of this is that very few plants will be able to grow in the darkness beneath the panels, making 900 acres of green land suddenly an organism desert.
This new metal panel desert will be directly in the middle of 3 habitats designated for their wildlife value at national and international levels. The solar farm is surrounded by a Site of Special Scientific Interest; a Special Protection Area; a Ramsar site (a wetland of international importance); and a Marine Conservation Zone. The Swale Estuary, Oare Marshes nature reserve, Graveney marshes, and Seasalter levels, are all protected areas, either by the Kent Wildlife Trust or the RSPB, due to their valuable habitats, and will all directly border the solar park. This causes an environmental phenomenon called ‘habitat fragmentation’, which is a key focus in many conservation programmes at the moment. Fragmentation occurs when an area of large connected habitat is split into small patches (a typical example of this is logging roads in the Amazon rainforest).
Fragmentation doesn’t always reduce the surface area of habitat significantly, but rather, the damage comes from the segregation of organism populations, causing ecological instability. Taking the hedgehog for instance: their numbers in the UK have fallen by 50% in the past 10 years, as they are particularly susceptible to fragmentation. Due to the increase of cars, roads, and fenced/walled gardens, hedgehogs have no way to move from one habitat to another, meaning that their search for food, mates, and locations to hibernate are made impossible by impenetrable barriers. This means that although people’s gardens have not necessarily got smaller, the hedgehog habitat has vastly decreased, because it has been split into small patches, which are difficult to cross between.
This small-scale example of fragmentation will be seen at a scale of 900 acres due to the solar park. Although no protected land is directly being destroyed, the huge barrier that Cleve Hill will present will impact many species.
However, there are also many species that will be impacted by direct habitat loss, as the solar farm covers 4 land types – arable land and meadows (79%), freshwater grazing marsh (7%), flood defences (12%), and the existing Cleve Hill sub-station (2%).
Species living on the freshwater dykes, open water scrapes, reedbed, saltmarsh, and seawall, will all be affected by the new structure.
Brent Geese use the marshland and fields to spend the winter, before migrating to the Arctic-tundra. Threatened Lapwings, Golden Plovers, Skylarks, Yellow Wagtails, and Corn Buntings feed and nest on the fields.
Birds of prey in the area will have their hunting grounds severely diminished, as they mostly hunt for small mammals and birds within the fields and reedbeds: this could cause a drop in numbers of Little Owl, Long-eared Owl, Short-eared Owl, Barn Owl, Tawny Owl, Kestrel, Marsh Harrier, Hen Harrier, Merlin, Hobby, Peregrine, and Sparrowhawk. These animals are extremely valuable, being the top of food chains, these are the species which maintain balance in an ecosystem, by controlling populations of mice, rats, voles, and small birds, which if left unchecked could decimate crops and plant communities.
Additionally, the large area of green land advertises itself as a safe haven for a wide range of migratory birds, who may have got lost or blown over to the UK on wind currents, and need to rest and feed before continuing their journey. Due to this, sightings of Rosy Starling, Montagu’s Harrier, Western Cattle Egret, Glossy Ibis, Turtle Dove, Bonaparte’s Gull, and many more, have all been documented in the area where the solar farm is due to be built. When these birds are flying over, they are attracted by a wide expanse of green next to the sea, offering shelter and food. However, once this landscape includes an uninterrupted sheet of metal 2.5 miles wide, these birds might not recognise the area as a safe refuge, and keep flying in search of a suitable habitat, causing starvation. The RSPB identifies starvation as the 4th highest risk to migratory birds, saying that ‘the risk of starvation is increased greatly when stopover sites are lost through climate change, or loss of habitat to development or agriculture’.
As well as providing much needed respite for these lost migrants, there are permanent residents which will also be displaced, or have their population destabilised by the solar farm. A colony of Little Terns, which nest precariously on the bare shingle beach. Avocets which were locally extinct in the UK throughout the 19th century, now have a stronghold nearby, with 20% of their national population in the Swale area. Cuckoos are often heard in the area, but numbers are rapidly dwindling, with worldwide population declining 66% in twenty years due to habitat destruction of their overwintering grounds in Africa, a trend which could be further exacerbated if their spring-summer habitats are also fragmented. A huge variation of wading birds and ducks call the Swale Estuary home, only a few of which have been named here.
Of course, all this bird life could not be supported if there was not also a huge amount of food, in the form of plants, invertebrates, and fish.
Hundreds of water voles have settled in this area, feeding on grasses and waterside reeds, maintaining clear waterways. The Swale canals are a key nursery bed for European Eels, which are critically endangered, after a population dip of 98% from overfishing, pollution, and fragmentation by dams disrupting migration. Many butterflies, moths, dragonflies, and other insect species take advantage of the huge plant diversity; thriving salt marshes, which Swale has the potential to be, have been found to be the third most productive ecosystem type in the world, after coral reefs and tropical rainforests.
Ecosystem destabilisation is a subtle and unpredictable process, which is easily avoided by maintaining the natural equilibrium created by balanced populations and habitats. A possible example to think about could be the local decline of birds of prey, or insectivorous organisms. The removal of predators like this causes a ‘trophic cascade’, in which all levels of the food web (trophic levels) are impacted by a single species. The results of this fall into 3 basic categories:
1. When a predator is no longer present, populations of their herbivorous prey begin to boom. Without a top predator to regulate their numbers, these animals put more pressure on the vegetation that they require for food, and can destroy large amounts of plant life. This then causes further problems, such as soil erosion and loss of habitat. Ultimately, humans are also impacted due to the resulting lack of soil fertility and clean water that depend on these plants.
2. Another problem involving the loss of vegetation, is the competition created between herbivorous species. Competition between species for the remaining plant life is high, so weaker species lose out to stronger ones, leading to the loss of weaker animals, as well as plant species. Increased competition, therefore, leads to a higher rate of extinction of the remaining organisms, and a lack of biodiversity.
This is normally avoided, as top predators have varied diets, which means they can pursue a new food source if one is running low, preventing the first source from being eradicated completely. This is one of the ways that top predators are able to maintain biodiversity and the balance of an ecosystem.
3. The presence of a top predator also helps to maintain balance in an ecosystem by influencing the behaviour and movements of its prey through the ‘fear’ of being caught. Animals that are prey move around in order to avoid their predators. This prevents plants and animals in any particular area of an ecosystem from being over-consumed, preserving food sources and habitats. In the absence of top predators, this regulation disappears, allowing certain areas of vegetation to be destroyed completely.
This process is very hard to predict in the long-term, even with in-depth knowledge of local species, because of how complicated the relationships between organisms are. There is currently no way to know for sure how the valuable ecosystems around Cleve Hill will be impacted by the solar farm. But it is certain that its construction will not create a higher biodiversity than the status quo (as the company claims), as no energy producing organisms can live under, between, or around the solar panels, aside from low-light fungi, which have limited energy sequestering scope and couldn’t support the ecosystem.
Before the solar farm project was approved, the Environment Agency (sponsored by DEFRA) had its own plans for the Cleve Hill site. The location was going to be reverted into pure salt marshes, as the arable fields were not as productive as hoped. This alternative plan for the area would bring about a variety of positive effects, such as acting as a buffering zone for any flooding and erosion from the sea, an additional hotbed of nutrients for plants and invertebrates, and most importantly, serve as an effective ‘carbon sink’.
A carbon sink is an area/reservoir that absorbs more carbon than it releases, in a process called sequestering. These sinks are extremely important, and are key to our recovery from climate change, being proposed as a way to slow the accumulation of greenhouse gases, which are released from burning fossil fuels. Oceans, vegetation, and soils are all methods of carbon sequestration, as they can absorb CO2 through chemical reactions, thereby taking it out of the air, where it causes damage to the atmosphere. A 2019 study by Annette Burden et al concluded that salt marshes in the UK would absorb 1 tonne of carbon per hectare per year. For comparison, an acre of 120-year-old tropical rainforest stores approximately 1.7 tonnes of carbon per year. The UK has the potential to create a habitat comparable to rainforest in effectiveness for carbon storage. The squandering of this resource draws into question how the disadvantages weigh up against the solar energy that would be produced at the site.
After fine examination of the infrastructure planning documents by the government, you will find that on page 73, there is a section named “details of licensed marine activities”. A subsection lists a number of substances, which have been authorised to be dumped in the sea, as waste or by-products from the building and maintenance of the solar farm. A direct screenshot of this list is pictured (right). After the popular movement in recent years towards banning microplastics, plastic straws, and dumping of waste products in the ocean, it is shocking to see that “plastics and synthetics” are listed as authorised substances. Metals, concrete, and marine coatings (which are waterproof, protective layers that are applied to surfaces exposed to water) would also be detrimental if deposited in the sea. This discovery adds another layer to the potential damage caused by Cleve Hill and raises the question where environmental concerns factor into the motivations behind its development.
It’s understandable why proponents for the Cleve Hill solar farm claim that opposition is based on NIMBYism, as many local residents frequently make use of this land for leisurely walks, to take in the scenery and nature, and this solar park will undoubtedly be a colossal change to the landscape they love.
The dismay at beautiful land being lost is a valid and valuable point; however, to disregard and minimise the genuine worries of local people by dismissing their complaints as pure NIMBYism, is to directly endanger them, and destabilise a globally significant ecosystem.
Supporters of the development claim that we should trust the government’s approval, as they would never take a decision that could cause such a catastrophic threat to human health and destroy thousands of species’ habitat, unless it was absolutely certain that the benefits of Cleve Hill outweighed the risks.
The world should of course be moving towards means of green energy production, but to conclude whether a project is truly ‘green’, we must weigh up the benefits of clean energy against the clear scientific risks described here.
However, as we will now discuss, the actual benefit of Cleve Hill solar park, the production of clean, green energy for the area, may not have been as important to the approval decision as hoped.
The extensive risks and criticisms which have been levelled at this project beg a number of questions. Why has the government given it the green light, what are the social implications of the project, and where does it fall in the broader scheme of green progress: balancing the need for renewable energy with ecological conservation. The development has faced much local opposition: from the environmental bodies previously mentioned; grassroots campaign group ‘Save Graveney Marshes’; Conservative MP for Faversham and Mid Kent Helen Whateley; and a petition with over 5000 signatures was sent to parliament.
Is national interest the first priority of private companies? Despite Wirsol and Hive Energy (the two companies behind Cleve Hill Solar Farm) being ‘green’ renewable energy corporations, their priority must still be the creation of profit, to remain a viable business. This potentially creates conflict between economic growth and genuine investment in a future of renewable energy.
So, how are Wirsol and Hive Energy planning on generating profit for their businesses?
Included in the technical plans for the development, is an import/export connection between the battery and the National Grid. This would be used to charge the energy storage facility, for example in times when solar energy is in short supply.
However, this connection also creates the possibility for the companies to generate profit in ways other than the sale of solar energy.
The National Grid is a private utility heavily regulated by the government. The companies behind Cleve Hill could buy electricity from the National Grid at off-peak hours, and then sell the same energy back, at times when the rates are higher, thereby creating profit from the buying and selling of electricity. Prices of energy can fluctuate greatly between night and day depending on the level of demand at any given hour. It is common practice for energy companies to take part in the buying and selling of electricity, with the function of maintaining security and stability in the energy markets. However, the issue here is the scale of capacity at Cleve Hill, and this function being in the hands of the private sector, which is entirely profit driven and may not have the public interest at heart. The possible consequence of this is the driving up of electricity costs.
There is precedent for this profit creation method, looking at Tesla’s Hornsdale Power Reserve in South Australia. Hornsdale is the current world record holder of the largest lithium ion battery, but is half the size of Cleve Hill’s proposal, meaning this Kent solar farm would have twice the profit-making potential. Hornsdale battery partially provided revenue for the company through the sale of stored electricity – in its first year it made $6.7 million this way.
It also profited through trading on the Frequency and Ancillary Services market, which essentially regulates short-term supply and demand in a power system. It is not entirely clear whether the companies behind the Cleve Hill development intend to also generate profit through this form of trading, but they certainly have the capabilities to do so, and may follow the example of the Hornsdale project.
It is not inherently a problem if alongside a solar farm development, an electricity back-up facility is also present. However, the size of the battery back-up exceeds what would be necessary to simply produce and sell electricity from the solar farm, raising the question what this extra capacity could be used for.
This would not only affect the public but also industries which rely on the ability to buy energy when it is cheap, potentially damaging manufacturing and costing jobs. Within the context of such a controversial development, the possibility of privatized profit being a major motivational factor only adds to the list of reasons it has faced such resistance.
Listed as part of the Planning Statement, written in November 2018, are benefits of energy storage facilities. These benefits include the ability to capture ‘free’ energy from the National Grid when it is surplus and redistributing it when demand rises. In the Statement, it is suggested that this function of the battery storage system will help producers of renewable energy ‘capture attractive market prices’, something developers suggest will reduce market risk for renewable projects in general, promoting the sector. The implication of this, is that the companies behind the Cleve Hill development would essentially be able to profit through this process of buying cheap, surplus energy from the National Grid, and selling it back when demand is high, potentially leading to an increase in energy prices overall, if the market becomes monopolized by private interests.
There should of course be financial incentives for development in the renewable energy sector. However, there are a number of reasons why solar energy should continue to develop through small-scale enterprises, rather than massive developments like Cleve Hill. Studies have suggested that a benefit of small-scale solar is the return on investment being channelled more directly into local communities. Whilst there are pros and cons to small and large scale, above the capacity of 20 megawatts, the cons seemingly outweigh the pros.
Additionally, due to the nature of solar power, it is most efficient at a small scale. Partly due to the equipment required to distribute the electricity and convert it into a usable form. This inefficiency suggests a fundamental flaw to the development itself.
An additional concern is the loss of potential energy. As electricity travels along a wire, as it does when being bought and sold from the National Grid, a small percentage of its energy dissipates during the movement. Cleve Hill has the potential to be wasteful in this sense, because the production of profit through this movement of electricity, will cause the loss of energy which could be used productively.
The energy, maintenance costs, and wasted productivity involved in the creation of the huge Cleve Hill battery, is surely not justified if its major purpose will be the generation of profit, at the expense of the general public, which surely has no place in a new green economy.
With so much opposition mounted against the Cleve Hill development, why on May 28th, Secretary of State Alok Sharma gave it approval, is up for question. Much of the surrounding dialogue has focused on the conflict between ecological conservation versus the priority of green energy. In reality, the future of each of these lies in unifying the two goals, we cannot have one without the other.
The false dichotomy that we must choose between saving habitats and making advances in renewable energy, was emphasised in the political response to Cleve Hill.
MP Helen Whateley wrote a ‘letter of concern’, which focused on the more obviously destructive elements of the development, such as its ecological impact and eradication of leisure space. She did not mention any of the potential health risks, or the precedent it could set in creating a green economy founded on corporate power. The main points from her letter are pictured (right), and we can see that she neglects to mention the most pressing issues that constituents have with the development. Many feel underrepresented, and that their concerns have only been half heartedly expressed to the government.
Perhaps the economic growth that Cleve Hill developers have promised to bring to the area has been prioritised, which may explain the lacklustre opposition levelled by Whateley – a gesture of opposition to appease the constituents.
Solar energy on this scale is unprecedented in the UK. As a result, the government’s approval of the development lacks context of other similar projects. Moving forward this means that decisions made regarding other solar parks of a similar, or even greater scale, may be approved partly because of the precedent set by the decision to approve Cleve Hill – just one of the many reasons why this is of national, not just local, significance.
Responses to the climate crisis must come from all sectors of society, including corporate. However, the disregard for the aforementioned issues raises the question whether private profit is being given priority over all other considerations. When there are major housing developments without the integration of solar panels appearing across the very same region, it appears that the nation is being led down a path towards a clumsy, destructive kind of green economy.
It seems justified to conclude that the Cleve Hill development promises to be an instance of ‘Green Energy done badly’.