E-mobility promises environmentally-friendly transportation: no sound pollution, no exhaust fumes, hardly any harmful emissions. Governments around the world are trying to encourage the use of electric cars with different incentives and ambitious targets – but currently they still make up only a tiny percent of the current stock of vehicles on our roads. Surveys show that electric cars have struggled to catch on for two main reasons: for most users the price is (still) too high, and consumers are concerned about driving range. But one thing is clear: the price will keep dropping. Technology is developing fast and with rising sales, production costs will fall. And when it comes to so-called “range-anxiety”, there are a whole host of start-ups and initiatives working on solutions.
When it comes to the environmental aspect of the technology, the reservations are different ones. Here, the main sticking points are the batteries inside the cars and the source of the electricity that ends up in the “tank”.
Lithium-Ion Batteries – Resource-Intensive Energy Storage
Whether it’s electric cars, pedelecs or laptops, lithium-ion (or Li-ion) batteries have become the energy storage method of choice. They are lighter and can store more energy than lead or nickel-metal hydride batteries, they require almost no maintenance and don’t lose storage capacity when only partially charged (the memory effect). But what is their environmental impact?
Currently, electric cars are built with lithium-ion batteries weighing roughly 300 kilos, in order to be able to achieve sufficient performance and cover adequate distances. They contain around three kilos of lithium as a charge carrier, plus a few kilos of nickel, manganese and cobalt that serve as electrode materials. The extraction of these materials is a cause for concern. Let’s take lithium for example. If the production of electric cars were to increase, there would be a huge leap in the demand for this valuable metal: there’d be a run on the extraction sites in Bolivia, Argentina and Chile (South America’s lithium triangle, where half of the world’s identified lithium is to be found), and because the lithium is stored in as yet untouched salt lakes, we can expect there to be huge overexploitation – resulting in both societal and environmental damage. The method used for extracting lithium – even when regulated – has significant environmental and social impacts.
At the same time, however, we can expect there to be a lot of development in the next few years. Lithium-ion batteries will get increasingly more efficient, meaning that the batteries will have less mass but achieve the same performance, thanks to constant progress in cellular chemistry. Bosch, for example, has already developed a new battery that has an ecological advantage: made of far less material, it allegedly has double the mileage of the electric cars currently available.
And people are also already looking for affordable alternatives. Researchers at EMPA and the Swiss Federal Institute of Technology have developed the Cat’s Gold battery, a mixture of iron, sulphur, sodium and magnesium. The advantage? These elements are available in large quantities, and are cheap too – unlike finite lithium. This battery isn’t currently suitable for use for energy storage in electric cars, but it’s an example that shows that there’s still a lot of untapped potential in the field – lithium is surely not the only option.
Second Life for Batteries
As well as the manufacturing process, another crucial aspect of a life cycle assessment of lithium-ion batteries: the amount (intensity) it is used. The life of a battery is directly related to the environmental impact that it has – the more charging cycles it can handle, the longer it can be used, meaning fewer batteries need to be produced in general. When, after seven or eight years, the batteries in electric cars no longer have the same performance and need to be removed from the cars, they can still be put to good use: for example by supplying a reliable power source to schools in India, or being put together with hundreds of other batteries in huge stationary storage systems.
This kind of energy storage could be being used much more in the future, as we switch over to renewable energies. On days when the wind doesn’t blow and the sun doesn’t shine, energy supplies fluctuate: to ensure a steady flow of electricity, we’ll need more temporary storage spaces. One huge-scale example is Elon Tusk’s new battery farm – full of the same batteries used in Tesla’s cars – that has been running since December 2016. It’s an energy storage project designed to help meet fluctuations in supply and demand, provide backup during energy fallouts, and even store solar energy for use after dark.
And lithium-ion batteries have another cool potential use too. Just like German startup Blue Inductive shows, rather than just feeding from the electric grid, electric car batteries can help out by feeding back into it. Vehicle-to-grid connections like this could help improve the stability of the grid, supply households and maybe even potentially reduce the need to build new power plants in the future.
And What About Recycling?
At some point every battery will reach the end of its life – but that doesn’t mean that the resources inside have been used up. Currently lithium-ion batteries are usually taken apart and melted down, allowing for the valuable metals such as cobalt and nickel to be – at least partially – recovered. But only a small part of the lithium is recovered and after that it usually ends up on sports grounds or being used to build roads. Rather than extracting new materials, it would be better to develop a more sophisticated recycling system that allows the materials to be used to again to make new batteries. And with the right obligations in place for the manufacturers, the recycling rate could also be increased.
It All Comes Down to What Ends up in the Tank
Different studies have suggested that rather than the manufacture, use and recycling of batteries, the type of “fuel” used to tank the vehicle has much more of an influence on electric vehicles’ green credentials. Researchers at Empa’s Technology and Society Laboratory have studied the estimated environmental impact of an electric car over an expected lifetime (an estimated 150,000 kilometres). The result: the biggest impact comes from the regular charging of the battery. If it’s charged in Europee, using electricity sourced from the usual mix of nuclear, hydroelectric and coal power stations, the negative impact on the environment is three times as big as the impact of the battery itself. But the result looks dramatically different when renewable energies are used, with the ecobalance improving by 40 per cent when the energy comes from hydroelectric power only.
According to Martin Wietschel, director of the Energy Industry department at the Fraunhofer Institute for Production Systems and Design Technology (ISI) producing electric cars requires significantly more energy than conventional vehicles – mostly because of the production of the battery. So, considering the environmental impact of the production of electric vehicles is rather hefty, and emissions only start to be reduced (in comparison to traditionally-fuelled vehicles) when they’re on the road, users need to take special care with how they charge and look after their vehicles, and also where the batteries end up.
And if that sounded gloomy, within Europe at least, using an electric car already has a positive effect in terms of greenhouse gases. According to researchers at the Empa, a conventional petrol-driven car would have to run at around three or four litres per 100 kilometres in order to be as environmentally-friendly as a car running on a lithium-ion battery that had been charged in Europe using that particular electricity mix. And with the switchover to clean energy, that result will only get better.
There’s Still a Lot to Be Done…
…before electric drives can become a seriously green alternative to conventional combustion engines. In order to conserve valuable raw materials, the batteries will have to be produced more efficiently, and we need to develop alternatives too – that use little to no rare minerals. And in order to be really in with a chance of proving their worth over conventional vehicles, it’s crucial we come up with better ways of recycling and reusing their batteries. And last but certainly not least, by cleaning up the energy grid and switching over even more thoroughly to renewable energy sources, so that cars can be charged with low-carbon alternatives, e-mobility will be a good thing all round.