BEVs emit more CO2 than conventional cars in parts of northern China: researchers

Battery electric vehicles (BEVs) are emitting more lifecycle CO2 than internal combustion engine (ICE) cars in parts of northern China, mainly due to the region's fossil fuel-dominated power generation mix, according to a recent study from Chinese researchers.

With strong policy support measures, including subsidies for vehicle purchases as well as government-sponsored technology and infrastructure rollouts in the past decade, China has emerged as the largest producer and buyer of BEVs globally.

Chinese policymakers see higher penetration of low-emission cars as essential to meeting the country's targets of peak CO2 emissions by 2030 and carbon neutrality by 2060.

But the study from Bowen Tang of Hubei University of Technology, Yi Xu of Wuhan University, and Mingyang Wang of State Grid Sichuan Electric Power Company suggests more BEVs do not always lead to lower emissions.

Assessing 30 Chinese provinces and municipalities, the study found higher CO2 emissions from BEVs than ICE vehicles in Beijing, Heilongjiang, Jilin, Tianjin, Shandong, Shanxi, and Hebei. In Beijing, where the difference is widest, a BEV would emit 45.7 metric tons (mt) in its lifecycle while an ICE vehicle would emit 42.2 mt.

In contrast, BEVs can help reduce CO2 emissions in other areas. In Yunnan, where the decarbonization impact is the strongest, a BEV's lifecycle emissions amount to nearly 12 mt while an ICE vehicle's emissions are 30.3 mt.

"The promotion of BEVs helps to reduce carbon emissions in most regions in China," the researchers said. "However, the effectiveness of the emissions reduction dramatically varies … due to the difference in electricity generation mix, thermal power generation technology, and electricity transmission efficiency."

The study highlighted the high proportions of coal, natural gas, and oil-fired power units in the electricity mix of the seven Chinese regions where BEVs have negative climate effects. Fossil fuels are responsible for 85%-90% of the power generation in three of them, and more than 90% in the other four.

"The effectiveness of the carbon emissions reduction through the promotion of [BEVs] is weakened in the regions with high penetration of thermal power," the study concluded.

Battery emissions

The study took into account the emissions from a car's production, operational, and recycling phases. It assumed a BEV emits 6.28 mt of CO2 while an ICE car emits 3.38 mt when their raw materials are extracted and processed, without considering regional disparity.

The greater pollution caused by a BEV in the production stage is due to emissions created by producing batteries, which contain cobalt, lithium, nickel, aluminum, and rare earth elements, according to the researchers.

"For BEVs, the key technology is around the battery," according to the study, whose analysis is based on the lithium iron phosphate battery option, one of the two main types used in China. Such a battery consists of a cathode and anode, electrolyte, separator, packaging, and battery management system.

The components' production involves a graphite-coated copper foil and binder, polypropylene, polyethylene, lithium hexafluorophosphate, dimethyl carbonate, aluminum foil, a wire, circuit board, and sensor whose emissions are taken into consideration.

"Sufficient knowledge of the lifecycle carbon emission of BEVs is necessary for the sake of evaluation of the CO2 emissions reduction, and guidelines on the BEVs' market development and policymaking," the study said.

Policy recommendations

Based on their findings, the researchers called on the Chinese government to create incentive schemes for original equipment manufacturers (OEMs) that use renewable energy during the production of BEVs.

They suggested the government can issue renewable energy certificates (RECs) to those companies—such certificates can be sold in a domestic trading scheme. Also, Chinese policymakers could design a vehicle score system that can promote the BEVs produced with low-carbon electricity.

Moreover, the government should provide more subsidies for driving BEVs in the areas with higher renewables penetration, the researchers said. Policies in fossil fuel-dominated areas should focus on generating more electricity from renewable sources, they added.

"Targeted promotion needs to be adopted in different regions," said the researchers, adding that the government should simultaneously improve cross-regional power exchange and transmission.

Electricity trading in China

However, some experts told Net-Zero Business Daily that focusing on renewables over EVs in some regions and vice versa in others might not help China achieve its climate goals.

"Given how slow vehicle fleet changes take place … I don't see the argument to micro-target BEV deployment according to current grid carbon intensity," said Michael Davidson, an energy researcher at the University of California San Diego. "By the time EVs are a significant fraction, the grid will already be cleaner."

Lara Dong, senior director for Greater China power and renewables businesses at IHS Markit, suggested Chinese policymakers also see promoting BEVs as a means to enhancing energy security, upgrading manufacturing capability, and reducing air pollution.

"I find the suggestion of 'promoting renewables before BEVs' a bit linear and overly simplified for China's policy setting and implementation approach," Dong said.

China, the world's largest GHG emitter, is targeting a 20% share of non-fossil fuel sources in its primary energy mix in 2025 versus 16% in 2020. It also wants new energy vehicles—such as BEVs and fuel-cell electric vehicles—to make up about 20% of new car sales in 2025.

The country has aggressively expanded renewable capacity in recent years. The China Electricity Council recently forecast that China's total installed renewable capacity will reach 1.3 TW at the end of 2022, or 50% of the national total. In the US, the world's second largest energy consumer, government figures showed renewables accounted for 25% of utility-scale generation capacity in 2020.

But government officials have admitted that grid improvement and market reforms are needed for China's utility sector to offer stable power supply while cutting emissions.

"It's crunch time for China to build a new electricity system as the penetration of renewables increases," the National Development and Reform Commission (NDRC) said in a policy commentary last month. "The system has to be more adjustable in a holistic way."

Beijing's goal is to establish a countrywide power market system that incorporates provincial, cross-regional, and national trading schemes by 2030. This is expected to facilitate more low-carbon energy exchanges among Chinese provinces and municipalities, all of which face a uniform target of a 40% renewable power consumption share by 2030.

Currently, local governments can trade renewable electricity via direct deals, RECs (also known as Green Certificates or Green Electricity Certificates), or in a pilot market. But no nationwide standards for renewable electricity have been established.

"Our goal is to set up common standards for regional markets" to reduce risks for market participants, said the NDRC, the central planning body. "That way, we would be able to better balance the power supply and demand [in the country]."

Posted 09 February 2022 by Max Tingyao Lin, Principal Journalist, Climate and Sustainability