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Could the green revolution begin down this disused Cornish mine?

Lithium—the crucial ingredient in the world’s best batteries—could help us kick the oil addiction. Jay Elwes descended down a dark tunnel in the countryside to find out more
March 22, 2018
The entrance to South Crofty, a 400-year-old copper and tin mine in west Cornwall, is shut off by two high red gates. Since the mine closed in 1998, a decade or so after that industry began grinding to a halt in the region, few people have ventured inside. But on a recent winter’s morning, Aaron Wilkins, a geologist who believes the mine has a future, drove Jay Elwes through the gates…

Down a long, narrow slope—no wider than a London Underground tunnel—we headed deeper into the Earth. The car’s headlamps lit the way until we could drive no further and had to continue on foot, emergency respirators attached to our belts. Several hundred metres below ground, the neat tunnel of the mine’s entrance gave way to bare stone, and a craggy, low ceiling. The floor of the mine was red—a sign of the iron drawn from the rock by the water, which ran down the walls, collecting on the ground in large pools. We were standing at the site of the Great Cross Course, an enormous geological fault line that cuts north-south across Cornwall and out beneath the Celtic Sea.

“Most rock is fairly impermeable,” Wilkins explained. “But where there’s a discontinuity, or a structure like a joint or a fault, you would expect to find mineralising fluids. And at depth, some of these structures will contain elevated temperatures which will increase the mineral content.” The iron turning the water red is not, however, the reason why there is now commercial interest in South Crofty—and neither are there new finds of copper or tin, the metals for which the mine was dug several centuries ago. The geological faults, Wilkins said, are where “you would expect to find elevated concentrations of lithium.”

Lithium is the very first metal, and the first solid, in the periodic table. If you remember it from school it is probably because lithium fizzles to nothing when dropped in water. It is extremely reactive on account of its atomic structure. A lithium atom has three electrons, one of which is particularly unstable, and it will give up that outermost electron very easily, which makes it highly reactive. There are many other alkaline metals with loose electrons, but lithium also happens to have the smallest atomic radius of all metals. This small atomic size means that “it contains the highest potential charge, or charge density, of all metals,” said Melanie Loveridge, a senior research fellow at the University of Warwick and a materials chemist who specialises in lithium-ion battery technology. “Imagine a box of tennis balls compared with a box of ping-pong balls—say each ball represents an atom. There will be more matter (and source of charge) in the box with the ping-pong balls, as they pack more densely.”

That compact structure gives lithium a significant property—it has a very high energy density: every chunk of lithium can hold much more energy in those little atoms than the average substance. And thanks largely to that property, lithium is the crucial ingredient in the world’s best batteries.

Ever-ready

Batteries are coming to be seen as the answer to the biggest problem facing modern energy networks—that of time. Once generated, electricity has to be used straight away. When you switch on the light in your bedroom, the energy powering that bulb was generated, perhaps many miles away, just 0.02-0.04 seconds ago; that is one tenth of a blink of an eye.

This instantaneity means that electricity generation has to match demand at every moment. And the trouble with demand is that it can go all over the place. One extreme example came during the 1990 World Cup, when England went down to West Germany in the semi-final penalty shoot-out. As the game ended, an emotional nation reached for the kettle and the national grid experienced a 2,800-megawatt surge in demand—a spike that amounted to six times the total capacity of the twin reactors of Dungeness nuclear power station. Fortunately, the grid didn’t fail, but fell back on emergency hydroelectric power. But that only makes the point—all kinds of costly contingencies have to be put in place to ensure that fluctuations in demand don’t make the power go out. The move to renewable energy redoubles the difficulty of the balancing act. Coal-fired power stations can burn all day and night, but with solar or wind a change in the weather can remove a source of generation. Suddenly, then, it is not only the demand but also the supply that must be constantly kept in kilter. A grid that stops working when the Sun goes in or the wind drops would be pointless. The way to get around this problem is to generate the electricity and then store it—and that means batteries. Strange as it may sound, in a world where “Keep it in the ground” is a favoured slogan of environmentalists, a green energy future now relies on mining—the mining of lithium.
“A recent Goldman Sachs research note asked its readers: ‘What if I told you lithium is the new gasoline?’”
In any battery, charged ions flow from one electrode to the other to give you an electric current. Some batteries can be recharged, and in that process, the flow of ions goes the other way. The first battery to find wide practical use was the lead acid variety, a 19th-century invention that delivered short bursts of high energy. This made it especially good for starter motors—car batteries are still of the lead acid type. The early 20th century brought the nickel-cadmium rechargeable battery and the zinc-carbon disposable (the traditional Ever-Ready make). Then in 1959 came the alkaline battery (such as Duracell) which largely conquered the market because of its longer lifespan.

Other varieties came and went before the first commercially-available lithium-ion battery was put on the market by Sony in 1991. Lithium’s energy density meant that these batteries lasted longer, were quicker to recharge and also lighter. The design has been continuously refined ever since. Its development has not been without problems—energy density has its downsides. In 2006, six million appliances containing lithium-ion batteries were recalled by manufacturers including Dell and Sony. Faults were causing the batteries to overheat, and in some cases to catch fire. As recently as this January, Hewlett Packard recalled around 50,000 laptops with lithium-ion batteries for the same reason.

Despite these problems, lithium-ion batteries have proved better than any other kind and are found in billions of mobile phones, laptops, and other devices. Increasingly, they are powering electric cars too. The first electric car to use the lithium-ion battery, the Nissan Altra, went on sale in 1998 and could travel 120 miles on a single charge. Since then, the batteries have got substantially better, and in 2017, Tesla, the electric car maker, released the Model S 100D, with a range of 335 miles.

Last year the UK government said no new diesel or petrol cars will be sold in Britain after 2040 and in February, city authorities in Germany won the right to ban diesel cars from certain districts. Other governments must follow this lead if they are ever to cut greenhouse emissions. In response to this change in the political weather, car companies are reducing their investment in new diesel and petrol engines and switching their attention to battery power instead.

Tesla is making perhaps the most high-profile dash for lithium—the president of Panasonic, which partners with the company, said last year that he expects the energy density of new lithium-ion batteries to increase by at least 20-30 per cent. The grandiose plans of Tesla grab the headlines, but older, cooler heads in the auto industry also want in on the lithium rush. Last May, the CEO of Volkswagen said that: “Anything Tesla can do, we can surpass.” General Motors confirmed to me that lithium ion batteries will play “a critical role in the development of electric vehicles” for the company, as it plans to introduce 20 new zero-emission cars over the next five years.

This revolution will go beyond transport and into our homes. Tesla already offers “the Powerwall,” a huge lithium-ion battery that integrates with solar panels. About the size of a conventional domestic boiler, it is installed in the same way, and  stores the energy generated during the day for when it is needed. Looking further ahead, with more powerful batteries, charged by renewable energy, it is no longer absurd to imagine homes, streets and entire neighbourhoods relying on lithium-ion power.

Big oil, big batteries

It is not only car makers who want a piece of the action. In an interview last July, Ben Van Beurden, CEO of Shell, said: “The whole move to electrify the economy, electrify mobility in places like northwest Europe, in the US, even in China, is a good thing.” The next car he buys, he said, will be an electric one. The boss of one of the world’s largest oil companies is effectively turning his back on petrol. Financiers are waking up too. A recent research note on electric vehicles by Goldman Sachs asked its readers: “What if I told you lithium is the new gasoline?”

The surge in demand has caused the price of the metal to soar. In 2000, a ton cost $2,000; now it costs over $11,000. And there is a way to go yet. Current global demand for lithium is 180,000 tons a year and when I spoke to Jeremy Wrathall of Cornish Lithium, the company working at South Crofty, he told me that by 2027, global demand could be as high as 800,000 tons.

Mining companies are happy, but manufacturers are growing concerned that there won’t be enough lithium to go around. “The auto-manufacturers have woken up to the fact that they need this product,” Wrathall told me, “and they don’t quite know where they’re going to get all of it from.” One Chinese car maker, Great Wall Motor Co, has bought part of an Australian mining company to guarantee itself a supply. Tesla has set up a “Gigafactory,” a $5bn, 4.9m square-foot building in the Nevada desert. It is devoted exclusively to the production of lithium-ion batteries—and is the biggest manufacturing plant in the world.

So how justified is the panic over supply? Fortunately, lithium is reasonably abundant and on current usage, the world has a 350-year supply. Unfortunately, it is concentrated in particular places, and is often hard to extract. The largest producers are in Australia and South America, especially Chile, home to half the world’s viable lithium deposits. The metal lurks in brines found beneath the Atacama desert. To mine it, the brine is pumped from underground and left to evaporate under the desert sun in shallow pools. The white residue that is left behind—there’s your lithium. It is scraped up, refined and exported.

Green mining

As the metal gets more valuable, sources that were thought uneconomical are beginning to look attractive, including South Crofty. Here, where I was standing—underneath Cornwall, in an abandoned tin mine—was Britain’s attempt to get in on the lithium act.

Not long ago, it was absurd to imagine that a new technological age could perhaps bring parts of Cornwall’s lost mining industry back to life. British mining has been in decline for as long as anyone can remember—at least since the 1950s, when close to one million Britons worked in the sector, overwhelmingly in coal. The fall of Cornish metal mining goes back further, to the 19th century. This was the high-water mark of an industry that at one point provided over a quarter of all jobs in the area, and whose roots can be traced through the medieval and Roman periods to prehistoric times. South Crofty itself, with some tunnels that date to the 16th century, is a reminder of this long history. But the industry had shrivelled to nothing.

The metal-rich waters are the result of the area’s unusual geology—a large expanse of the far west of Cornwall is on granite, which was originally lava and has radioactive properties. The Earth’s crust is hotter here at a shallower depth than usual; that gives rise to a sort of pressure cooker effect. Water, trapped in the rock structures, heats up over hundreds of millions of years and leaches out the lithium, which occurs naturally in the granite. This is how deposits of lithium-rich brine are formed. In the context of the Great Cross Course fault line, brines collect in underground reservoirs. These have long been known about, but in past times were regarded with dread. If miners accidentally broke into a large body of water, they risked drowning. One such incident occurred in 1893 at the Wheal Owles mine near St Just, when a shaft flooded and 19 men and one boy died.

Today, however, it is waters rich in lithium that are wanted. In 2017, the start-up company Cornish Lithium raised £1m to begin an exploratory analysis of the potential for extraction, with the immediate focus on South Crofty. The mine’s tunnels form a lattice of shafts extending for miles and running to a depth of over 800 metres. Geologists there, including Wilkins who accompanied me on my visit, are building a computer model of the excavated area, not only the tunnels but the geological features and fault zones through which the old mine is cut.

Britain plugs in

Britain will never match the enormous output of the global lithium mining companies or the huge lithium-ion battery manufacturers. When it comes to lithium-ion cells, each year Britain makes units with a total capacity of 1.4 gigawatt hours. In comparison, Japanese production is 14GWh per year and China’s is 72GWh. If the UK is to thrive in the lithium age, it will not be through volume, but through technical innovation and the canny application of new lithium-based capabilities, especially their use alongside renewable energy.

Kip Jeffrey is the Director of the Camborne School of Mines and he has been closely involved with work at South Crofty. “In Cornwall, particularly [the energy grid is] more or less at saturation level,” Jeffrey told me. “We can produce so much renewable energy, but what we can’t do is actually put it into the grid, because it’s saturated. What we really want is to be able to use local distribution systems. Which, of course, requires “large-scale battery storage,” and “that looks like being… lithium-ion.”

Cornish Lithium told Jeffrey that “their real aspirations is not only to produce a lithium product,” but one “that spurs the usage of that material in the vicinity.” “Who’s to say,” he said, “you couldn’t have a lithium-ion or other type of lithium products down here in the West Country?”

“I think we’re as well placed as any of the other advanced nations,” Kumar Bhattacharyya told me. He is a professor of manufacturing at Warwick, which is one of the leading European institutes in the development of battery technology and the largest in Britain. When it comes to lithium-ion technology, he said, “the government is spending enough money—or hoping to spend enough money.” That’s quite a change: “until now, there was very little done. Other than what we were doing at Warwick.” It looked like a classic case study of that British syndrome where “you do good research and then some other country or some other company takes it over.” But last year, the government announced it would put £246m into battery technology research, with a promise of more to come. Meanwhile, in the private sector Dyson is ploughing £1bn into research into “solid state” batteries, the next step after lithium-ion, for new electric cars which it hopes to have road-worthy by 2020.

If Britain—and the world—can achieve greater separation between the moment electricity is generated and the moment that it is used, the benefits will be enormous. Likewise, if we can wean our cars off fossil fuels, transport will be dramatically cleaner and more sustainable. Research by Bloomberg suggests that there will be 530m electric cars on the road by 2040. A 2017 IMF working paper by academics from Georgetown University predicted that by 2040, electric car use could cut global oil demand by 21m barrels a day (current consumption is 96m). Kicking the oil addiction would not only be good news for the environment, but could change international relations too, by diminishing the often-malign influence of the oil states.

Those pitch-black tunnels beneath Cornwall, then, could not merely help us keep the lights on, but help reset international diplomacy too. The next question is whether Britain can get itself plugged in—or whether it will be left behind in the dark.