Photo: Courtesy of State Grid Nanjing power supply company

 

To address power demands during the summer peak, the State Grid Nanjing power supply company in East China's Jiangsu Province recently organized the "car network interaction" initiative, involving reverse discharge, time-based electricity pricing, and promotional activities aimed at guiding vehicle owners to charge their electric cars during off-peak hours. These efforts leverage the bidirectional resource characteristics of electric vehicles, enhancing the interactive response capabilities of Nanjing's electric vehicle charging facilities.

"Car and network interaction" primarily includes intelligent and orderly charging, bidirectional charging and discharging (V2G), and other forms of energy management. V2G allows users to use their electric vehicles as mobile energy storage devices—charging during low-demand periods and discharging power back to the grid during peak hours. This creates a dynamic and efficient energy system of "new energy vehicles + power grid," effectively shifting peak demand and filling valleys.

The initiative covers more than 350 public charging stations in Nanjing. Charging time coupons are distributed through the e-charging app, WeChat welfare groups, and other channels, encouraging vehicle owners to stagger their charging times. Additionally, during the activity period, stations like Geek Space Jiangbei New District Station and Jiangning Station regularly host "high temperature cool" events, where cooling products are provided to customers while charging, and staff assist customers in obtaining coupons, further guiding them toward off-peak charging.

To enhance price guidance, State Grid Nanjing Power Supply Company selected 14 urban public stations to implement time-based electricity pricing, with the lowest night-time electricity price set at 27 cents. This pricing strategy, combined with time-sharing service fees, helps shift the charging load to off-peak periods.

Moreover, to fully utilize the bidirectional adjustment potential of electric vehicles, State Grid Nanjing Power Supply Company invites owners to participate in reverse discharge from 7 to 10 p.m. at Jiangning Station. V2G activities are conducted regularly, with a discharge subsidy of 4 yuan ($0.55) per kWh offered to encourage user participation in the vehicle-grid interaction.

As of now, the proportion of charging stations participating during peak and valley times has increased by 107.8 percent. A total of 35 vehicles have been invited to participate in V2G discharge, with a maximum discharge power of 71.8 kW per vehicle. The total reverse discharge power has reached 201.1 kW, with a cumulative reverse discharge of 340 kWh, effectively supporting the summer peak demand.