Transition to electric vehicles could create unwanted air pollution hotspots in China and India

Electric vehicles are a cornerstone of the global energy transition, but a new Princeton University-led study finds that refining critical minerals needed for electric vehicle batteries could create pollution hotspots near manufacturing sites. It has been proven that there is.

Researchers focused on China and India and found that if these countries fully domesticated their electric vehicle supply chains, each country’s sulfur dioxide (SO2) emissions could increase by up to 20% above current levels. I discovered that there is. The overwhelming majority of these SO2 emissions are likely derived from the refining and manufacturing of nickel and cobalt, minerals that are critical to today’s electric vehicle batteries.

“Much of the discussion around electric vehicles has focused on minimizing emissions from the transportation and power sectors,” said corresponding author Andlinger Associate Professor of Public and International Affairs and Associate Professor of Energy and Environment. said center Wei Peng. “But we’re showing here that the impact of electric vehicles goes beyond vehicle tailpipe emissions and electricity. It’s also about the entire supply chain.”

The researchers published their findings in the journal Environment Science & Technology, arguing that countries need to think strategically about building clean supply chains when developing decarbonization plans.

In the case of battery manufacturing, the researchers emphasized the importance of developing and enforcing strict air pollution standards to avoid unintended consequences of the transition to electric vehicles. They also proposed the development of alternative battery chemistries to avoid process-based SO2 emissions in today’s battery manufacturing.

“If you dig deep into any clean energy technology, you’ll find that there are challenges and tradeoffs,” said lead author Anjali Sharma. He completed his research as a postdoctoral fellow in Penn’s group and is currently an assistant professor at the Climate Center. Research and Ashank Desai Center for Policy Research at the Indian Institute of Technology Bombay. “The existence of these trade-offs does not mean we stop the energy transition, but it does mean we need to act proactively to mitigate these trade-offs as much as possible.”

A story of two countries

China and India have good reasons to avoid SO2 emissions. SO2 is a precursor to particulate matter, which causes many cardiovascular and respiratory problems. Both countries already suffer from high levels of air pollution. In 2019 alone, about 1.4 million premature deaths in China and 1.7 million in India were caused by exposure to fine particulate matter.

However, the two countries are at different stages of electric vehicle development. Mr. Peng said that while China’s domestic supply chain for electric vehicles remains the same, India is still in the early stages of supply chain development. This comparison helped researchers identify short-term priorities as they continue or begin building a domestic supply chain for electric vehicles.

“China needs to think about how to clean up its existing supply chain, but India has an opportunity to build a better supply chain from scratch,” said Peng, who is also a core faculty member at the Policy Center. Research on energy and environment. “Both situations come with their own challenges and opportunities.”

In India, the lowest-hanging fruit would be to focus first on cleaning up pollution from the power sector. To this end, it is necessary to utilize mature technologies such as flue gas desulfurization and implement strict measures to prevent SO2 pollution at thermal power plants. China, which already has strict emissions controls for its power sector, needs to shift its focus to reducing SO2 emissions from the battery manufacturing process, something the researchers said they are less familiar with.

However, the researchers stressed that ignoring emissions from battery manufacturing would be a grave mistake. In a scenario where China and India fully domesticated their supply chains, prioritizing a cleaner grid would have little effect on reducing SO2 emissions. Instead, only scenarios that focused on cleaning up the battery manufacturing process avoided SO2 pollution hotspots.

“People generally think that moving to greener technology is always a win-win. There are also benefits for the climate and air quality,” Sharma said. “However, not accounting for manufacturing may reduce carbon and nitrogen oxide emissions but increase the burden of air pollution on communities near manufacturing centers.”

A human-centered approach to decarbonization

Although the analysis focused on China and India, the researchers argued that if left unchecked, pollution from battery manufacturing will become an increasingly global challenge as electric vehicle penetration increases. Even if countries like China and India outsource battery manufacturing, Sharma said, without a strategy to reduce SO2 emissions, they would simply push the problem onto other countries.

“It’s important to look at electric vehicles from a global supply chain perspective,” Sharma said. “Even if India were to abandon building its own domestic supply chain and instead choose to import from elsewhere, the pollution would not go away; it would simply be outsourced to other countries.”

In addition to policy recommendations for aggressive air pollution standards, which are likely to be made at the national or sub-national level, the researchers believe that changing the chemistry of electric vehicle batteries could be used on a more global scale. We also considered how undesirable SO2 emissions can be avoided.

Currently, most electric vehicle batteries rely on cobalt and nickel, but the rise of alternative chemistries that use iron and phosphates (so-called lithium iron phosphate batteries) has led to the mining and refining of cobalt and nickel. Some of the concerns involved may be avoided. By avoiding these two minerals, SO2 emissions during manufacturing were significantly reduced in scenarios with high lithium phosphate battery penetration.

In any case, Penn said the findings should be kept in mind by people as they develop decarbonization plans, as even the most promising technologies can have undesirable and unintended consequences. He said it would serve as a reminder.

“We know many of the key technologies to reduce carbon emissions,” Penn said. “But the other part is how are people affected by those technologies? My approach is to think about the best ways in which technology and people intersect, because those strategies are Because it produces the best outcomes for the most people.”