Electric vehicles or EVs use batteries instead of petrol for power. With zero emissions, this key technology might be our great hope to reduce oil use and turn back climate change. As policy-makers and car manufacturers around the world are making the shift toward an EV-dominated future, we have to ask: Are they really as clean and green as they’re made out to be?
There are a lot of factors that determine a car’s impact on the environment. While EVs don’t exhaust harmful gases themselves, they can still have an overall negative effect depending on how they are manufactured and charged up. Let’s take a look at the issues that EVs still need to address.
Clean energy source is the key
Electric vehicles generally produce less greenhouse gas than most traditional cars. However, our power grid’s energy source makes all the difference. Burning too much coal to power our EVs will defeat the purpose of going electric as we’re just transferring our car’s exhaust to the coal plants. Ultimately, electric grids need to go green before we can truly consider our EVs emission-free.
Right now, the average grid in the United States typically includes a mix of fossil fuel and renewable resources. As a result, electric vehicles in the country are almost always greener than their gas-powered counterparts. If we factor in the vaunted efficiency of electric motors, this difference is further amplified.
The average gasoline-powered vehicle produces about 410 grams of carbon dioxide per mile. This number may vary depending on two factors – fuel economy and the carbon content in the vehicle’s fuel. In contrast, the average electric vehicle produces about 150 grams of carbon dioxide per mile and this average heavily depends on whether or not the EV is charged on a coal-heavy grid.
The good news is that most countries are cleaning up their electric grids. Over the last decade, the United States has seen hundreds of coal plants decommissioned and utilities are shifting towards a mix of natural gas, solar, and wind energy. As a result, electric vehicles are getting cleaner each year.
Reliance on raw materials
Electric vehicles use lithium-ion cell batteries. To manufacture these power cells, you’ll need lithium, cobalt, and other rare earth elements. MIning for these chief ingredients has been linked to serious environmental and social problems. Cobalt mining creates hazardous tailings and residue that can wreak havoc to the area, endangering not only the environment but communities as well. Furthermore, smelting metal ores emit harmful gases like sulfur oxide and lead.
About 70 percent of the world’s cobalt supply comes from Congo. Poverty has pushed people, even children, to work in unregulated mines where they risk health and safety every day.
Lithium is mostly mined in Australia and South America. To extract this metal, large amounts of groundwater are used depriving farmers and herders of this precious resource. Compared to gas-powered cars, EVs use up about 50 percent more water to manufacture. Radioactive substances found in rare earth elements are another major concern.
Recycling technology must be improved
Early generation EVs will soon reach the end of their lives. Right now, our recycling technology still lags behind and we might end up with tons of spent batteries in landfills if we don’t do anything about it.
Lithium-ion batteries are far more efficient compared to lead-acid batteries. However, their recycling rates are a measly 5 percent against the latter’s 99 percent.
Scientists have pointed out that precious metals from spent batteries can be recovered and reused. Unfortunately, with our limited technology, recycling lithium-ion batteries will contribute to air pollution and use up large amounts of water.
“The percentage of lithium batteries being recycled is very low, but with time and innovation, that’s going to increase,” said Radenka Maric, a professor at the University of Connecticut’s Department of Chemical and Biomolecular Engineering.
Finding a second life for older batteries is one approach that is being considered. “For cars, when the battery goes below say 80 percent of its capacity, the range is reduced, but that’s not a constraint for stationary storage,” said to Amol Phadke, a senior scientist at the Goldman School of Public Policy at the University of California, Berkeley.
Electric vehicle manufacturers like BMW, Nissan, and Toyota are trying to make this a possibility. They are designing batteries with second-life use in mind. If successful, we will soon see our EV batteries used for grid storage or as backup storage for solar power.