17.4 C
Munich

Are electric vehicles really as green as advertised?

Governments around the world և Automakers are promoting electric vehicles as a key technology in combating oil: controlling climate change. General Motors has announced that it intends to stop selling “light trucks” of new gasoline-powered cars by 2035, which will focus on battery-powered models. Last week, Volvo said it would be faster, fully electric by 2030.

But when electric cars and trucks enter the mainstream, they face a stubborn question. Are they really as green as they are advertised?

Although experts widely agree that plug-in machines are more climatic than traditional machines, they can still have their environmental impact, depending on how they are charged and manufactured. Here’s a guide to some of the biggest concerns and how they can be addressed.

How electricity is produced is important

In general, most electric cars sold today tend to emit significantly less heat than most gasoline-powered cars. But a lot depends on how much coal is burned to charge those plug-in cars. And the grids still have to get a lot cleaner until the electric vehicles really do emit.

One way to compare the climate impact of different vehicle models is with the Massachusetts Institute of Technology’s interactive online tool (www.carboncounter.com/#!/explore), which tried to incorporate all relevant factors. to produce cars, how much gasoline ordinary cars burn և where does the electricity to charge electric vehicles come from?

If you assume that electric vehicles get their power from the average U.S. grid, which typically includes a mix of fossil fuels and renewables, they are almost always much greener than conventional vehicles. Even if electric vehicles require more emissions from batteries, their electric motors are more efficient than traditional internal combustion engines that burn fossil fuels.

For example, the all-electric Chevrolet Bolt can be expected to produce 189 grams of carbon dioxide per mile of its life. On the contrary, it is estimated that the new Toyota Camry, which runs on gasoline, produces 385 grams of carbon dioxide per mile. The new Ford F-150 pickup truck, which is even less energy efficient, produces 636 grams of carbon dioxide per mile.

But it is only average. On the other hand, if the Bolt were to be charged with coal in a heavy-duty network like the one in the Midwest, it could actually be a little worse for the climate than a modern petrol-powered hybrid car like the Toyota Prius. but uses the battery to boost its mileage. (The coal-bolt would still hit the Camry և F-150).

“Coal tends to be a major factor,” said Jeremy Michalek, an engineering professor at Kareg Mellon University. “If you have electric cars in Pittsburgh that are plugged in at night, nearby coal plants are forcing you to burn more coal to refuel them, the climate benefits are not so great, you can even have more air pollution. »

The good news for electric vehicles is that many countries are trying to clean up their grids. Over the past decade, utilities in the United States have retired to hundreds of coal stations, moving to a mix of lower-emission natural gas and wind energy. As a result, researchers have found that electric vehicles have also become cleaner. And they are more likely to be cleaner.

“The reason electric vehicles look like an attractive climate solution is that if we can turn our networks into zero carbon, vehicle emissions will go down the road,” says MIT Associate Professor of Energy Studies. Tranchik. “Yet even the best gasoline-burning hybrids will always have an emissions base that they can not be low.”

Raw materials can be problematic

Like many other batteries, lithium-ion cells, which power most electric vehicles, rely on raw materials such as cobalt, lithium, and rare earth elements that are associated with serious environmental and human rights issues. Cobalt was especially problematic.

Mining cobalt produces hazardous tailings, slag that can penetrate the environment, and studies have shown that cobalt and other metals are highly exposed to nearby communities, especially children. Extraction of metals from ores requires a process called smelting, which can cause sulfur oxide and other harmful air pollution.

70% of the world’s cobalt is mined in Congo, much of it in unregulated “craft” mines where workers, including many children, dig metal from the ground using only hand tools that endanger their health and safety, warns human rights activists groups:

The world’s lithium is mined in Australia, or from salt blocks in Argentina, Bolivia and Chile. As a result of these actions, a large amount of groundwater is used to pump out salt water, extracting water available to indigenous farmers and shepherds. The water needed to make batteries means that electric vehicles require 50% more water than traditional internal combustion engines. Rare land deposits in China often contain radioactive materials that can emit radioactive water or dust.

Focusing first on cobalt, automakers – other manufacturers committed to eliminating “artificial” cobalt from supply chains – said they would create batteries that would reduce or eliminate cobalt altogether. But the technology is still being developed, and the prevalence of these mines means that these commitments are “unrealistic,” said Michael Daudin of Pact, a non-profit organization working with Africa’s mining communities.

Instead, says Daudin, producers need to work with those mines to reduce their environmental footprint so that miners can work in safe conditions. If companies act responsibly, the rise of electric cars will be a great opportunity for countries like Congo, he said. But if they do not, “they will endanger the environment, the lives of many, many miners.”

Recycling can be better

As earlier generations of electric vehicles begin to reach the end of their lives, the challenge is to prevent the accumulation of spent batteries.

Most electric vehicles today use lithium-ion batteries, which can store more energy in the same area than older, more commonly used lead-acid batteries. But while 99% of lead-acid batteries are recycled in the United States, the estimated recycling rates for lithium-ion batteries are about 5%.

Experts note that used batteries contain precious metals, other materials that can be recovered and reused. Depending on the process used, recycling batteries can also consume large amounts of water or emit air pollutants.

“The percentage of recycling of lithium batteries is very low, but over time it will increase,” said Radenka Maric, a professor in the Department of Chemical Biomolecular Engineering at the University of Connecticut.

A different, promising approach to disposing of used electric vehicle batteries is to find a second life in storing them և other applications. “For cars, when the battery goes down to, say, 80% of its capacity, the range is reduced,” said Amol Padke, a senior fellow at the Goldman School of Public Policy at the University of California, Berkeley. “But this is not a barrier to inpatient storage.”

Various automakers, including Nissan and BMW, have tested the use of old electric car batteries to maintain the network. General Motors has announced that it has designed its battery packs with the idea of ​​using a second life. But there are challenges. Reusing lithium-ion batteries requires extensive testing and upgrades to ensure that they are reliable.

Properly covered, it will withstand a great deal of adverse conditions for over a decade or more, according to a study by MIT researchers last year.

LEAVE A REPLY

Please enter your comment!
Please enter your name here