A recent study published in Engineering explores the emerging landscape of ultrafast electric vehicle (EV) charging stations in China, offering a detailed examination of usage patterns, grid implications, proposed solutions, and the associated financial costs. As the global EV market continues to expand remarkably—with China at the forefront in adoption—gaining a nuanced understanding of the infrastructure challenges and opportunities is imperative for sustainable growth in this sector.
The research, led by Yang Zhao, Xinyu Chen, and Michael B. McElroy, is grounded in an extensive analysis of real-world charging data from over 15,000 EVs across fast-charging stations in ten Beijing districts. Using this empirical dataset, the team developed a series of future-oriented scenarios that reflect evolving EV specifications and charging behaviours. Key parameters incorporated into the modelling include charging power levels, battery capacities, and charging session durations, all critical to anticipating infrastructural needs.
One particularly significant finding concerns the non-linear relationship between increased charging power and station load. While it might be intuitively assumed that doubling charging power would result in a proportional doubling of station load, the study demonstrates that this is not necessarily the case. In larger charging stations equipped with numerous chargers, the peak power demand rises far less dramatically—by under 30%—even when charging power is doubled. This phenomenon arises because shorter charging durations reduce the probability of session overlap. For instance, in simulation scenarios ranging from S1 to S7, where the maximum EV charging power increased tenfold, the peak load at the airport charging facility only increased by 4.90, underscoring the moderating effect of session timing on load intensification.
To address the challenge of limited power capacity at charging stations, the researchers evaluated two broad mitigation strategies: a dynamic waiting system and integrating energy storage solutions. The dynamic waiting strategy entails staggering specific charging sessions to alleviate peak loads. Notably, at the airport station—where the total capacity is equivalent to 120 kW multiplied by the number of chargers—this approach alone was sufficient to accommodate ultrafast charging needs across all simulated scenarios (S1 to S7), albeit with a manageable increase in waiting times.
In parallel, the study assessed the role of battery-based energy storage systems in absorbing peak demand surges. Although effective, this solution comes at a considerably higher cost. The unit cost of lithium-ion energy storage in China is approximately four times that of conventional pad-mounted distribution transformers. Despite the expense, energy storage offers distinct advantages: It obviates the need for grid capacity upgrades and allows for greater flexibility in station deployment, especially in areas where grid reinforcement is impractical or delayed.
The financial implications of infrastructure upgrades were also a focal point of the study. The chargers themselves and the associated distribution transformers were among the key cost drivers identified. By comparing the costs of various upgrade pathways, the researchers offer a strategic framework for stakeholders—particularly policymakers and utility providers—to optimise investment decisions. Their findings support the establishment of large-scale ultrafast charging stations featuring chargers with power ratings between 350 kW and 550 kW in regions with high charging demand. Such an approach, the authors argue, represents a cost-effective and scalable response to the anticipated surge in EV charging needs.
Overall, this study provides a comprehensive and data-rich perspective on the future of ultrafast EV charging infrastructure in China. Its integration of empirical evidence with forward-looking scenario analysis highlights the complexity of managing high-power charging networks. It presents actionable insights for infrastructure planning, grid integration strategies, and regulatory frameworks. As China continues to lead the global EV transition, studies of this kind will prove critical in ensuring that the supporting infrastructure evolves in a manner that is both economically and environmentally sustainable.
More information: Yang Zhao et al, Future Ultrafast Charging Stations for Electric Vehicles in China: Charging Patterns, Grid Impacts and Solutions, and Upgrade Costs, Engineering. DOI: 0.1016/j.eng.2025.01.015
Journal information: Engineering Provided by Higher Education Press