China, the world's largest new-car market, is expected to surpass the United States to become the world's largest market for electric vehicles with its dramatically increased sales since the second half of 2014, according to an expert at the University of California-Davis.

China's sales of electric vehicles, including pure battery electric and plug-in electric vehicles (PEVs), grew fourfold, from 19,713 in 2013 to 84,900 in 2014, thanks to the new and strengthened policies in the country, said Yunshi Wang, co-director of the U.S.-China Zero Emission Vehicle Policy Lab at UC-Davis.

"From the data of last December and January this year, the sales of PEVs in China have surpassed that of the US," he said. "I expect the annual sales in China are likely to leapfrog the US this year."

Wang's lab was established last September between UC-Davis and the China Automotive Technology and Research Center, the administrative body that oversees China's auto industry, to enhance collaboration on clean-vehicle adoption.

Under the five-year memorandum signed between the two sides, the lab is tasked to advise the Chinese local and national governments on the PEV policies of California as well as study the policies' incentive effectiveness and customer demand on car-charging infrastructure.

"California is a leader in promoting new-energy vehicles in the US, and China is very interested in its PEV strategies and zero-emissions policies," Wang said.

Some partnerships have been started between California and major Chinese cities such as Beijing and Guangdong, where California has ongoing collaborations on environmental and carbon cap-and-trade programs, Wang said.

Since last year, some big cities in China have beefed up efforts to encourage people to buy clean-energy vehicles in an effort to reduce carbon emissions, like Beijing's preferential treatment for PEV buyers in an auto-license lottery, and Shanghai's waiver of the license-plate auction fee. China also set a goal that by 2016, 30 percent of all government fleet-vehicle purchased will be electric.

Wang, however, pointed that China's PEV market faces some challenges and barriers, such as local protectionism and a lack of car-charging infrastructure.

"There are more than 100 traditional automobile manufacturers in China, and cities and provinces have been creating a variety of barriers to protect their local PEV manufacturers while disfavoring car makers from other cities and regions," he said.

The removal of regional protectionism will help increase sales of electric vehicles in China, said Wang, who used the example of BYD Co Ltd, a Chinese manufacturer of automobiles and rechargeable batteries based in Shenzhen.

"When Shanghai allowed BYD to enter its market, we saw a dramatic increase in sales of electric vehicles," Wang said.

"So far, imported electric vehicles do not enjoy the government's preferential policies, so domestic auto manufacturers can be protected," he said. "From our perspective, we believe such 'national protectionism' would be phased out in the future, and only two to three national automobile manufacturers will remain."

Another challenge is a lack of charging facilities. Wang said his lab and a Shanghai automobile research center collaborated last year. According to their initial findings, 95 percent of the survey respondents expressed a desire for electric vehicles, as the electricity bill is only a quarter to half of the gas expense.

"But because there were no charging facilities in the neighborhood, they had to recharge the vehicles with wires hanging from the windows of their homes, usually in high-rise buildings," he said.

His lab now is studying the demand for charging stations and the consumer market in California and China in order to provide intellectual support for the design of PEV policies.

In 2013, China's vehicle sales approached 22 million, topping US light-duty vehicle sales of 15.6 million. China's vehicle total is expected to exceed 280 million by 2020.

liazhu@chinadailyusa.com