Within the global energy revolution aimed at replacing fossil fuels with renewable energy sources and transitioning from gasoline and diesel cars to electric vehicles (EVs), China plays a leading role. An inevitable direction of development is the creation of a new energy system that integrates energy sources, the grid, load, and storage systems.
As the fleet of new energy vehicles approaches 100 million units, a huge number of electric vehicles are moving beyond their initial function as transport and becoming a vital element of next-generation infrastructure. It is projected that China will operate between 110 and 160 million electric vehicles by 2030, and this number could grow to 300–400 million by 2040.
The expansion of ultra-fast charging networks reveals a growing problem of synchronized load on local grids. For example, the simultaneous charging of 5 million electric vehicles at 10 kW each would result in a demand of 50 million kW, which significantly exceeds the peak capacity of most municipal grids.
Therefore, it is critically important to shift the process of electric vehicle charging from an uncontrolled, decentralized scheme to a coordinated bidirectional energy flow. The key to this lies in implementing Vehicle-to-Grid (V2G) technology, which allows electric vehicles to dynamically interact with the power grid.
Essentially, V2G transforms electric vehicles from passive energy consumers into active mobile storage units. Cars can consume energy during periods of low demand and return electricity to the grid during periods of high consumption. This not only reduces grid overload but also opens up new income streams for owners participating in wholesale energy markets.
When using a medium-capacity battery of 70 kWh, utilizing surplus cyclical power to support the grid can yield a cumulative lifetime profit of 15,000 to 75,000 yuan (equivalent to $2,240 to $11,198 USD). Thus, electric vehicles are transforming from depreciating consumer goods into income-generating assets.
Public concerns mainly revolve around battery longevity and safety. Studies show that properly managed V2G operations do not accelerate battery degradation; on the contrary, they can help extend the calendar life. Modern lithium iron phosphate (LFP) batteries used in electric vehicles can withstand about 3,000 full charge-discharge cycles before capacity drops to 70 percent. However, a typical passenger car consumes only about 500 cycles over 10–15 years of operation, leaving significant reserve for additional applications.
Technologies such as bidirectional pulsed impact allow for more uniform lithium distribution, suppress lithium plating, and improve fast charging and low-temperature performance. At the same time, operating in V2G mode keeps batteries predominantly in a partial state of charge. This prevents calendar life degradation caused by long-term storage at a full charge. When combined with intelligent risk monitoring, these systems effectively minimize safety incidents.
Three typical V2G application scenarios
V2G application is already implemented in three standard scenarios. The first is the 'point' scenario in industrial parks, where vehicle batteries work together with photovoltaic generation and energy storage facilities. The second is the 'line' scenario in transportation, where integrated solar energy, storage, and charging systems, as well as batteries used for replacement in heavy truck stations, can power passenger cars, reducing the load on the main grid. The third is the 'zone' scenario in buildings, where comprehensive 'home-vehicle-grid' systems provide holistic management of building energy consumption and V2G operations.
In the long term, V2G is expected to become the primary form of distributed short-term energy storage in China. Given that China's urban landscape is dominated by high-rise buildings and conditions for installing stationary energy storage systems at home are limited, using electric vehicles parked in underground garages for energy storage is a more practical option.
According to China's 15-Year Plan (2026–2030) for developing a new type of energy system, the total controllable charging capacity provided by V2G should reach 50 million kilowatts by 2030. By 2040, as the growth of stationary energy storage slows down, V2G energy storage capacity may exceed 4 billion kilowatt-hours. It is conservatively estimated that the total battery capacity of 350 million electric vehicles will reach 25 billion kilowatt-hours by 2050, which will be sufficient to meet the country's one-day emergency electricity needs.
The next five years will be a launch phase for the V2G industry. As technical standards improve, market mechanisms are introduced, and business models mature, over 100 million electric vehicles will form an extensive network of 'mobile power banks' for the grid, providing strong support for the energy transition.