FTS second-life application for used EV batteries: energy buffer for charging
06 October 2015
UK-based Future Transport Systems (FTS) has developed, with support from Ricardo, an energy buffer system using second-life EV batteries for charging stations. The FTS E-STOR concept provides improved functionality for the EV driver while also reducing peak demand on the distribution network.
The system enables higher capacity EV fast-charging from a standard 3 kW electrical connection. In addition to avoiding additional stress upon the local distribution network, E-STOR can also play an important role as part of a smart grid, in acting as a useful energy buffer to absorb surplus generating capacity—something that is particularly attractive as the intermittent renewable proportion of the generating mix increases.
E-STOR is a modular and expandable energy storage platform and will be launched initially with two products; the E-STOR 50 and E-STOR 100, providing respectively 50 kWh and 100 kWh storage. The second life EV batteries used for these products make the E-STOR platform cost-effective. While the system is designed to be battery agnostic, the high capacity lithium-ion units currently being used are derived from Renault EVs, representing an attractive reuse opportunity between on-road use and eventual end of life recycling.
In June 2015, the E-STOR product was named winner of the innovation category in the British Renewable Energy Awards 2015, hosted by the Renewable Energy Association at The Savoy, London. E-STOR is being commercialized and will be marketed as a CE marked product, through a new wholly-owned FTS company, Connected Energy.
Ricardo’s support for FTS included the implementation of interface and communication stacks to facilitate FTS application software. This included developing and testing the various commutation protocols to link the multiple energy storage systems and power electronics on the E-STOR architecture. Ricardo developed the TCP/Modbus, CAN, RS 485 and Ethernet communications and selected the appropriate control system hardware to implement the E-STOR application software.
Okay, they've got a use for these batteries between the vehicle and the recycler. I'd like to see an analysis of how many there will be compared to the size of the fleet as it expands, and how much of the demand-side issue they'll be able to address.
My suspicion is that the ratio of buffer-batteries to vehicle batteries will be small, meaning there will be a market for cheap stationary batteries. If those are cheap enough it may make it pay to recycle the lithium ex-vehicle batteries sooner than physical end of life.
Posted by: Engineer-Poet | 08 October 2015 at 06:41 AM