Jiangsu pioneers station-to-grid battery swap station

An electric vehicle undergoes a battery swap at the Fangshan Service Area. [Photo provided to chinadaily.com.cn]

At the Jiangning Fangshan Service Area in Nanjing, Jiangsu province, a Nio battery swap station fed 20 kilowatt-hours of electricity back to the grid in just three minutes at a rate of 400 kilowatts on Sept 10. The site is the province's first facility enabled by station-to-grid (S2G).

S2G refers to an emerging form of energy interaction that allows idle batteries stored at swap stations to discharge power directly to the grid. Unlike traditional vehicle-to-grid (V2G) systems, which depend on electric vehicle batteries and V2G-enabled chargers, S2G stations maintain a larger battery inventory and centralized management capabilities.

Under the station's energy control system, discharge levels can be precisely managed. A single station can supply as much power as more than 10 electric vehicles. The system also forecasts battery swap demand, manages charging during off-peak hours, and discharges stored energy during peak hours, enabling large-scale, bidirectional grid integration.

In March, Nanjing's "Ningdiantong" full-scenario V2G demonstration project, led by State Grid Nanjing Power Supply Company, was selected as one of the country's first national pilots for vehicle-grid interaction at scale.

The Fangshan Service Area station is one of five project application sites, specifically supporting passenger vehicle battery swapping. The station hosts 21 battery packs with a total capacity of about 1,600 kilowatt-hours and a maximum swap power of 600 kilowatts.

On July 14, the site completed its bidirectional charging and discharging transformation and was officially connected to the grid, making it the first in Jiangsu to achieve large-scale grid-linked operation. Routine operations began on Sept 1. In addition to supporting vehicle swaps, the station also generates revenue by participating in peak-shaving power dispatch.