EVgo, America’s largest public fast-charging network for electric vehicles (EVs), has launched a commercial installation of second-life battery storage at a public DC fast charging station. Following a pilot program at University of California San Diego (UCSD), this second-life battery system has been unveiled at an operational EVgo fast charging station located in Union City, CA at 3960 Smith Street.

EVgo has integrated second-life BMW i3 batteries to store energy from the grid generated during peak solar hours and later use that stored energy to fast-charge EVgo customers during periods of high demand.

In addition to reducing curtailment of solar or wind power, a benefit to all grid users, EVgo is also commercially demonstrating the reuse of EV batteries for grid benefit.

The increased use of second-life battery technology is an exciting development, keeping fast charging of clean electric vehicles affordable and insulating the grid from spikes in electricity demand. Reusing batteries as backup for charging is a win-win for the economics and the environmental benefits of EVs.

—Austin Brown, Executive Director of the UC Davis Policy Institute for Energy, Environment and the Economy

The EVgo Union City site began operating earlier this summer and already has two 50-kilowatt (kW) DC fast chargers. The second-life battery system integrates two BMW i3 battery packs into a single housing.

Each second-life battery pack has a capacity of 22 kWh and when combined with a 30 kW inverter offers a 30 kW/44 kWh energy storage system capable of demand charge management.

EVgo conducted a successful test case at the UCSD microgrid prior to launching the second-life battery system in Union City. This test case and the Union City implementation are part of the first of three technology demonstration projects that EVgo is currently engaged in with support from the California Public Utilities Commission:

1. energy storage to support electric vehicle fast charging;

2. a vehicle-to-grid (V2G) technology project; and

3. high power electric vehicle charging (50kW+).

BMW provided the recycled energy storage packs from BMW i3s and continues to provide ongoing technical support. Princeton Power Systems provided inverter hardware and integrated the inverter with the battery packs into a productized system. Kisensum developed software controls for the battery system and managed software integration for the overall site level demand charge management.

EVgo plans to deploy additional energy storage resources at stations across the network and sees energy storage as a key technology to enable affordable DC fast charging.

EVgo saw a record year in 2017, with its network of chargers providing the equivalent 40 million miles of emissions-free electric driving, a significant year-over-year increase compared to the approximately 26 million EV miles charged by the network in 2016.