Whether electric cars can improve Chinese air needs to meet these two conditions

Electric vehicles play a key role in China's plans to improve air quality and reduce carbon dioxide emissions, according to us media. For one thing, the researchers believe, private electric cars in China will help reduce carbon dioxide emissions if their owners slow down for them during off-peak hours. Second, replacing buses and taxis with electric cars will effectively improve air quality.

Private electric cars in China can have a positive effect on carbon dioxide emissions if the government encourages car owners to charge their cars slowly during off-peak hours, researchers from Harvard University and Tsinghua University found. And let wind power be used more effectively. On the other hand, if you use "fast charging mode" to charge electric vehicles quickly, it may be counterproductive.

At the same time, China's buses and taxis have also made a significant contribution to nitrogen oxide emissions, a major precursor to air pollution, the report said. The team found that replacing buses and taxis with electric cars was the most effective way to improve air quality. The study was published in the journal Nature Energy.

"The study offers a more nuanced strategy for reducing carbon dioxide emissions and improving air quality in China," said Yuehan·baoersen of Harvard University and Maikeer·maikeerluoyi of the School of Engineering and Applied Sciences(SEAS) of the Department of Earth and Planetary Sciences And ... "

"It's very important to manage the charging of electric cars to maximize the benefits of renewable energy," said Chenxinyu, SEAS Environmental Science and Engineering research assistant and co-author of the report. "

The researchers used real-time power demand data and driving patterns in Beijing and its suburbs to build integrated models of energy systems, the report said. They found that the way electric cars are charged -- whether in low-energy slow charging or high-energy fast charging models -- plays an important role in wind energy integration. In general, the use of 30 minutes or less of fast charging mode in cars mainly occurs during peak power demand. As a result, electricity demand increased during peak hours, bringing more coal-fired generators online. As these generators operate at night, there are fewer opportunities to take full advantage of the available wind power.

Kelisi·niersen, executive director of Harvard's China project, who co-authored the study, said: "if the government encourages car owners to wait until late at night to charge their electric cars in slow charging mode(it will take hours), Then you can make full use of the wind energy during off-peak hours. "

In terms of reducing air pollution, the researchers found that public transport fuelled by gasoline or diesel -- about 30,000 buses and 66,000 taxis -- accounted for nearly 20 percent of nitrogen oxide emissions, equivalent to 8.2 million private cars. Switching buses and taxis to electric vehicles in Beijing will significantly reduce the total emissions of nitrogen oxides and help improve air quality.

"Changing public transport to electric vehicles and encouraging private car owners to charge their vehicles during off-peak hours is the most effective strategy to reduce Beijing's nitrogen oxides and carbon dioxide emissions," Maikeerluoyi said. He added: "This strategy also applies to other cities in the world that use a lot of coal-fired power generation." "

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