By Ayan Banerjee
Without a doubt, you have some type of battery close to you as you’re reading this. Be it the battery in your laptop or phone or the AA’s in a torch. Our reliance on this technology is set to increase rapidly as countries and individuals race to become greener.
The shift to renewable energy sources such as solar or wind is incentivising governments to invest in grid-based energy storage systems. Presently, most grids operate on a second-by-second supply to meet demand which is possible by the flexibility of fossil fuels in changing the power delivered at any time. However, the intermittent nature of most renewable energy sources means the same approach would lead to widespread power cuts and overloads as supply would rarely match demand at any time. Therefore, large-scale batteries offer a storage for energy to be deposited when excess is being produced and drawn from when there is a supply deficit, therefore, eliminating any supply issues.
This all sounds very complicated to run; does it actually work in reality? This is where South Australia provides a useful case study. By most accounts, the world’s largest battery installed by Tesla in 2017 has been a great success. A region of the world previously plagued with astronomically high electricity prices has seen the major price drops since the battery was brought online. It was also a financial success, earning AU$23.8M in the first half of 2018 spurring the investment in future international battery uptake. This combined with electrification of other industries such as the car industry is set to increase the demand of batteries significantly over the current century. Therefore, for something produced on this scale, we must heavily scrutinise its sustainability.
In May 2016, thousands of dead fish were plucked from the waters of the Liqi river, where a toxic chemical leak from the Ganzizhou Rongda Lithium mine had wreaked havoc within the local ecosystem. Some eyewitnesses reported seeing cow and yak carcasses floating downstream, dead from drinking contaminated water. It was the third such incident in the space of seven years in an area which has seen a sharp rise in mining activity, including operations run by BYD, the world’ biggest supplier of lithium-ion batteries for smartphones and electric cars at the time. After the second incident, in 2013, officials closed the mine, but when it reopened in April 2016, the fish started dying again. Lithium-ion batteries are the most common type of battery used presently with 12kg of Lithium in the battery of a Tesla Model S. Demand for lithium is increasing exponentially, and it doubled in price between 2016 and 2018.
The production process for lithium, or more specifically lithium carbonate, involves drilling holes in salt flats and pumping salty, mineral-rich brine to the surface. This brine is left to evaporate, and the resulting salts are filtered so the lithium carbonate can be extracted. Although a very simple process, it uses large amounts of water and can be time-consuming – taking between 18 and 24 months.
It’s a relatively cheap and effective process, but it uses a lot of water – approximately 500,000 gallons per tonne of lithium. In Chile’s Salar de Atacama, mining activities consumed 65 per cent of the region’s water. This is having a big impact on local farmers – who grow quinoa and herd llamas – in an area where some communities already have to get water driven in from elsewhere.
There’s also the potential for toxic chemicals to leak from the evaporation pools into the water supply. These include chemicals (such as HCl) which are used in the processing of lithium into a form that can be sold, as well as those waste products that are filtered out of the brine at each stage. Research in Nevada found impacts on fish as far as 150 miles downstream from a lithium processing operation. A report by Friends of the Earth states that lithium extraction inevitably harms the soil and causes air contamination. Like any mining process, it is invasive, scarring the landscape and damaging the water table whilst polluting the earth and local wells.
Conversely, lithium may not be the most problematic ingredient of modern rechargeable batteries. It is relatively abundant and may in fact be generated from seawater in future, albeit through a very energy-intensive process.
Two other key ingredients, cobalt and nickel, could potentially cause a huge environmental cost. Cobalt is found in huge quantities right across the Democratic Republic of Congo and central Africa, and hardly anywhere else. The price has quadrupled in the last two years.
One of the biggest challenges with cobalt is that it’s located in one country, so there’s a strong motivation to dig it up and sell it; as a result, there’s a large incentive for unsafe and unethical behaviour. In the Congo, Cobalt is predominantly extracted in ‘artisanal mines’ by hand often using child labour without any protective equipment.
So how can we reduce all of these environmental and human effects? Many scientists argue that new battery technology needs to be developed that uses more common, and environmentally friendly materials to make batteries. Researchers are working on new battery chemistries that replace cobalt and lithium with more common and less toxic materials. However, these need to be cheaper and have higher energy density than the batteries before it to incentivise a transition. With all of these associated environmental and human impacts, it’s imperative that we scrutinise all points of the battery manufacturing supply chain so we can actually make a true ‘green’ transition.