Driven by the global energy transition and the pursuit of carbon neutrality, the electric vehicle (EV) industry is surging at an unprecedented pace. As a central enabler of decarbonization in the transportation sector, EVs are not only transforming traditional mobility patterns but also serving as a critical link in the transformation of the energy system through deep integration with the power grid. This synergistic development addresses the challenges posed by the massive scale-up of EV adoption in meeting electricity demand, while simultaneously giving rise to innovative models such as the energy internet and vehicle-to-grid (V2G) technologies. These developments offer new pathways for building a clean, efficient, and resilient energy system.

Electric Vehicles: From Means of Transportation to Mobile Energy Storage Units

Traditional internal-combustion vehicles have long been mere energy consumers, but the widespread adoption of electric vehicles has fundamentally transformed their role. The battery packs in electric vehicles are, at their core, distributed energy-storage systems with capacities far exceeding typical household electricity needs. For instance, an electric vehicle with a 500-kilometer range typically has a battery capacity of 60–80 kilowatt-hours—enough to meet the daily electricity consumption of an average home for three to five days. When millions of such vehicles are connected to the power grid, their combined storage capacity can reach the gigawatt-hour scale, comparable to the capacity of a large pumped-storage hydropower plant.

This characteristic transforms electric vehicles into a “mobile energy storage pool” for the power grid. During periods of low electricity demand, EVs can use smart charging systems to absorb excess grid power; during peak demand or when renewable generation is insufficient, they can feed stored energy back into the grid, thereby smoothing out load peaks and valleys. This bidirectional interaction not only enhances the grid’s regulation capabilities but also shifts EVs from mere energy consumers to active participants in the energy system, offering a new solution for the energy transition.

Vehicle-to-Grid Interaction Technology: The Technological Cornerstone of Collaborative Development

Vehicle-to-Grid (V2G) is the core technology for enabling coordinated operation between electric vehicles and the power grid. By leveraging bi-directional charging/discharging equipment, intelligent metering systems, and communication protocols, V2G allows electric vehicles to engage in real-time information exchange and energy transactions with the grid. The technical architecture of V2G comprises three key layers:

At the hardware level, bidirectional charging piles and on-board bidirectional inverters provide the foundational support. Modern charging equipment is now capable of upgrading from unidirectional charging to bidirectional charge-and-discharge operation, and certain vehicle models—such as the Nissan Leaf and the Tesla Model 3—already support V2G functionality.

At the communication layer, 5G, the Internet of Things, and blockchain technologies together establish a secure and efficient information channel. By continuously monitoring grid frequency, voltage, and load conditions in real time, the system can precisely schedule the charging and discharging of electric vehicles, thereby ensuring the safety and cost-effectiveness of the interaction process.

At the software level, artificial intelligence algorithms and big data analytics optimize scheduling strategies. By leveraging users’ travel patterns, electricity price signals, and grid demand, the intelligent management system can develop personalized charging and discharging plans that both meet user needs and maximize system efficiency.

The Multidimensional Value of Collaborative Development

The synergistic development of electric vehicles and the power grid generates multidimensional economic, environmental, and social value. At the economic level, V2G technology can reduce grid investment costs. According to research by the International Renewable Energy Agency (IRENA), by 2030 the global energy storage potential of electric vehicles could reach 120–240 gigawatt-hours, potentially cutting grid-side energy-storage investments by approximately US$200 billion. Moreover, by participating in demand-response and ancillary-services markets, vehicle owners can earn additional revenue, thereby creating a win-win “vehicle-grid” model.

The environmental benefits are equally significant. Smart charging of electric vehicles can enhance the integration of renewable energy. When wind and solar power generation exceed demand, EVs are prioritized for charging, thereby storing green electricity; conversely, when generation falls short, stored energy is released, effectively addressing the intermittency of renewables. This interactive model can increase the utilization rate of renewable energy by 10%–15%, accelerating deep decarbonization in both the transportation and power sectors.

At the societal level, coordinated development enhances the resilience of the energy system. When extreme weather or sudden grid failures cause power outages, electric vehicles can serve as emergency power sources to supply critical loads such as homes and hospitals. During the 2021 Texas blackout in the United States, some EV owners leveraged V2G technology to provide power to their neighbors, demonstrating the practical value of this approach.

Challenges and Future Prospects

Despite the promising outlook, the coordinated development of electric vehicles and the power grid still faces numerous challenges. An incomplete standards framework, an underdeveloped market mechanism, and insufficient public awareness all hinder large-scale deployment. Moreover, technical issues such as battery degradation over time and the safety of charging and discharging require further breakthroughs.

Looking ahead, driven by technological advancements and supportive policies, coordinated development will enter a new phase. Breakthroughs in technologies such as solid-state batteries and wireless charging will enhance the efficiency and safety of vehicle-to-grid (V2G) interactions; the emergence of new market players—including virtual power plants and aggregators—will refine business models; and the integration of carbon-trading markets will provide stronger economic incentives for coordinated development. By 2030, it is projected that more than 30% of electric vehicles worldwide will be equipped with V2G capabilities, giving rise to a vehicle-to-grid market worth trillions of dollars.

The synergistic development of the electric-vehicle industry and the power grid represents not only technological innovation but also an inevitable step in the transformation of the energy system. As hundreds of millions of electric vehicles become intelligent nodes within the energy network, humanity will truly enter a new era of deep integration between transportation and energy, providing powerful momentum for achieving global carbon neutrality. This transition requires the concerted efforts of governments, enterprises, research institutions, and consumers—through technological innovation, policy guidance, and market development—to ensure that electric vehicles genuinely serve as a green link connecting transportation and energy.