Second-life batteries are all the rage in the clean tech space right now as companies rush to define new business models that maximize the effort put into the initial construction of the battery, as well as the value extracted throughout their primary, secondary, and maybe tertiary use cases.
EVgo has announced that it is getting into the game as well, with the addition of second-life batteries to its grid-tied public fast charging systems. It set up its first such system in the northern California city of Union City, which taps into the residual storage capacity of used BMW i3 batteries to store energy during peak solar generation and dispensing the power as needed to reduce the overall strain its fast charging systems can have on the grid.
“EVgo is pushing energy storage innovations forward in the EV space, as we deliver solutions for our customers that are good for the environment and the economics of fast charging,” said Cathy Zoi, CEO of EVgo. “Our Union City station is just the start of EVgo’s work integrating advanced energy storage into our rapidly expanding fast charging network across the USA.”
Second-life batteries have been removed from vehicles that have been damaged in an accident or that have degraded to the point where they are no longer efficient to use in a vehicle. These batteries can be bundled together into much larger stationary storage arrays which don’t care as much about the energy density of the batteries. Repurposing batteries in this way maximizes the value that can be extracted from the battery, spreading the energy, carbon emissions, and investment in the initial battery over a longer period of time.
“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,” said Austin Brown, Executive Director of the UC Davis Policy Institute for Energy, Environment and the Economy. “Reusing batteries as backup for charging is a win-win for the economics and the environmental benefits of EVs.”
The Union City site with the new second-life battery installation hosts two 50kW DC fast charging stations which are now complemented by two BMW i3 battery packs with a capacity of 22kWh each. The packs have been wired up through a 30kW inverter that allows the packs to add significant value to a charging session by avoiding demand charges that might otherwise be incurred.
The logic governing the battery system and integration was developed by energy management solution provider Kisensum, which was recently acquired by ChargePoint. On the hardware side, Princeton Power Systems created the custom battery pack by adding an inverter and meshing it together with the two battery packs into a single production-grade system.
EVgo also plans to utilize the stationary storage to explore the potential for feeding power back into the grid in response to utility requests, generating a financial return for EVgo at the same time. Moving forward, EVgo sees energy storage as a core technology for enabling affordable fast charging to customers.