China’s EV ultrafast charging stations: Challenges, solutions, and costs

A new study published in Engineering delves into the future of ultrafast charging stations for electric vehicles (EVs) in China, exploring charging patterns, grid impacts, solutions, and upgrade costs. As the global EV market continues to expand rapidly, with China leading the way in EV adoption, understanding these aspects is crucial for sustainable development.

The research team, led by Yang Zhao, Xinyu Chen and Michael B. McElroy, analyzed real-world charging data from over 15,000 EVs at fast-charging stations across ten districts in Beijing. They established scenarios for current and future EV specifications and charging parameters, considering factors such as charging power, battery energy, and charging times.

One of the key findings is related to the impact of increased EV charging power on station loads. Contrary to the common assumption that doubling charging power would double the station load, the study shows that this is not the case. Larger stations with more chargers experience a relatively modest peak power increase of less than 30% when fast-charging power is doubled. This is because shorter charging sessions are less likely to overlap. For example, in the simulations, as the maximum EV charging power increased tenfold from scenarios S1 to S7, the peak load at the airport charging station increased by only a factor of 4.90.

The researchers also investigated two generalized solutions to address the issue of insufficient power capacity at charging stations: a dynamic waiting strategy and the deployment of energy storage. The dynamic waiting strategy can effectively decrease peak loads by delaying some charging sessions. For instance, at the airport EV charging station, with a total power capacity of 120 kW times the charger number, it can satisfy ultrafast charging demands from S1 to S7 using only this strategy, with a reasonable increase in waiting times.

Regarding energy storage, it can buffer peak loads, but the cost is a major consideration. The unit cost of lithium-ion battery energy storage is approximately 4 times higher than that of pad-mounted distribution transformers in China. However, energy storage has its advantages, such as not requiring grid capacity expansion and enabling more flexible installation.

When it comes to upgrade costs, the study identified chargers and distribution transformers as the main expenses. Comparing different upgrade strategies, the research provides valuable insights for policymakers and industry players. The results suggest that deploying large ultrafast charging stations with chargers between 350–550 kW in high-demand regions could be a viable solution to meet the surging charging demands of EVs in China. This research offers a comprehensive understanding of the future of EV ultrafast charging stations in China, which will contribute to more informed decision-making in charging infrastructure planning and grid management.

The paper “Future Ultrafast Charging Stations for Electric Vehicles in China: Charging Patterns, Grid Impacts and Solutions, and Upgrade Costs,” authored by Yang Zhao, Xinyu Chen, Peng Liu, Chris P. Nielsen, Michael B. McElroy. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.01.015. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.