On April 10, at around 11 a.m., in the Chengdu Shuangliu District, a citizen named Zhu Liang made history by selling electricity from his electric vehicle (EV) back to the grid. He parked his car, plugged in the charging and discharging gun, scanned a QR code on the charging station, and confirmed the discharge via his smartphone. Within just a few minutes, his vehicle discharged 5.2 kilowatt-hours, earning him a revenue of 5.2 yuan. This marks the first successful instance in Sichuan where an electric vehicle has injected power into the 10 kV public grid, taking a significant step toward large-scale vehicle-grid interaction.
Vehicle-grid interaction refers to the energy and information exchange between new energy vehicles and the power grid through charging stations. This includes smart and orderly charging, as well as bidirectional charging and discharging. In simple terms, it allows electric vehicles to adjust their charging patterns based on grid demand or to supply electricity back to the grid in exchange for subsidies. The key technology enabling this interaction is V2G (Vehicle-to-Grid), which allows new energy vehicles to act as “mobile power banks,” helping to alleviate pressure on the power grid.
According to Fu Xiaowei from the State Grid Tianfu New District Power Supply Company, “Owners can also earn money by taking advantage of the price differences in electricity.” Why is there a push to treat electric vehicles as “power banks”? The answer lies in saving costs for power supply and reducing peak demand on the grid.
Zhu Liang calculated the potential earnings from his electric vehicle. “With a battery capacity of about 40 kilowatt-hours, if I sell 80% of my car’s electricity using V2G, I could earn around 25 yuan per transaction, assuming a price of 0.2 yuan per kilowatt-hour during off-peak hours and 1 yuan during peak hours.” He added that vehicle-grid interaction not only helps vehicle owners earn money but also plays a crucial role in saving substantial power supply costs and alleviating grid pressure.
As electricity demand has surged in recent years, addressing this through the expansion of electricity transmission infrastructure can be very costly. Data suggests that by 2040, there could be 300 million electric vehicles in China. By employing V2G technology, the overall power support capacity for the grid could reach between 2.9 billion to 3.5 billion kilowatts, enabling better management of electricity supply and demand.
According to a joint release by the National Development and Reform Commission and other departments, “Electric vehicles will connect with the power supply network through charging and swapping facilities, establishing a two-way interaction system for information and energy flows, effectively leveraging the flexibility of power batteries as controllable loads or mobile energy storage.” Recently, the Southern Power Grid organized the first cross-provincial vehicle-grid interaction event in China, involving 63 cities across five provinces: Guangdong, Guangxi, Yunnan, Guizhou, and Hainan. During this event, over 100,000 electric vehicles acted as “mobile power banks,” with interactions exceeding 500,000 kilowatt-hours.
What explorations have been conducted in Chengdu? Three projects have been selected as national pilot programs, and a number of charging and discharging stations are set to be constructed or renovated by August 30. Recently, the National Development and Reform Commission, the National Energy Administration, the Ministry of Industry and Information Technology, and the State Administration for Market Regulation jointly announced the first batch of large-scale vehicle-grid interaction pilot applications. Chengdu’s three selected projects include the “Smart Vehicle-Grid Interaction Pilot Project,” the “Co-energy Integration Virtual Power Plant Pilot Project,” and the “Urban Mobile Power Bank Vehicle-Grid Interaction Pilot Project.” The construction of the Tianfu Airport Starry Sky Energy Storage Charging and Discharging Station is part of the “Smart Vehicle-Grid Interaction Pilot Project.” This project, submitted by Chengdu Teli Electric New Energy Co., aims to upgrade and transform several charging and discharging stations across Chengdu, focusing on residential and office areas.
According to Hu Haifeng, the technology director of Chengdu Teli Electric, “We plan to upgrade 50 charging stations by June 30, covering over 300 charging piles. If all discharge at once, they could provide electricity for one to two thousand households.” Additionally, a vehicle-grid interaction demonstration station was commissioned last October in Chengdu’s High-tech Zone.
Jia Zhiqiang from Chengdu Jiao Investment Group’s energy development department explained that this demonstration station is part of the “Co-energy Integration Virtual Power Plant Pilot Project.” Currently, it uses discharged power for lighting in office buildings and underground parking lots. “By August 30, we will continue to construct or renovate 60 charging and discharging stations in Chengdu, covering various applications such as urban logistics, sanitation vehicles, and office parks,” he stated.
Moreover, the 7,000 electric buses currently operating in Chengdu can also serve as large “power banks,” providing electricity in emergencies. Luo Qing, manager of the New Energy Division at Chengdu Bus Asset Management Company, mentioned that the city’s bus group intends to remodel 52 charging piles at the Jinsaha Bus Hub and the Chengdu Jiaozi Bus Base by June 30. Last year, they launched a comprehensive energy demonstration station, equipped with two V2G charging piles for pilot testing and collaborated with leading battery manufacturers to upgrade the discharge technology for over 50 long-range buses.
What challenges remain for further promotion? To ensure smooth two-way communication, a comprehensive information-sharing mechanism is needed among the battery, vehicle, charging station, platform, and power grid. Many citizens have expressed concerns about whether repeated charging and discharging could damage battery life. Jia Zhiqiang reassured them, stating, “Lithium iron phosphate batteries used in new energy vehicles can handle around 3,000 charge-discharge cycles. A vehicle with a range of 400 kilometers would typically need to charge only once or twice a week, even with daily commutes.” He emphasized that even daily charging and discharging would fall within the battery’s normal lifespan.
Currently, the communication protocols between vehicles and charging stations, as well as the pricing and settlement mechanisms, still require further standardization. Chen Zhuo, head of the Energy Management Department of Teli Electric’s Southwest Region, pointed out that for effective vehicle-grid interaction, there needs to be a robust information-sharing system in place. The goal is to establish key technical standards for bidirectional charging and discharging equipment, vehicle technology specifications, communication protocols, and safety measures by the end of 2025.
For companies, investing in hardware infrastructure represents a significant expense. The current price for charging and discharging stations is roughly double that of standard charging stations. To encourage more businesses to participate in vehicle-grid interaction, Chengdu has implemented supportive measures, including subsidies for recognized bidirectional charging and discharging stations. The State Grid Tianfu New District Power Supply Company is currently exploring commercial models for vehicle-grid interaction in collaboration with Chengdu Teli Electric New Energy Co. Additionally, policies announced this year in Chengdu also aim to enhance the interaction level of electric vehicle charging and swapping facilities.
