Optimal usage and properties of battery storage units using 2nd life batteries

Research Project, 2022 – 2027

Second life batteries are batteries that have ended usage in their first application but are in a sufficiently good condition to allow a second application. With the expected electrification of transportation there will be very large quantities of such 2nd life batteries of highly different degree of ageing, properties and expected remaining useful life. The abundance, their short response-time, and the low need of energy and power density, make grid applications of BESS using 2nd life batteries highly interesting. Examples of potential applications are frequency control, energy balancing to compensate for variations of renewable energy sources, and power peak shaving. Optimal battery management of such systems, however, is still poorly studied and highly challenging, because of the large variability in the properties of old cells and a general lack of knowledge of 2nd life ageing.
The purpose of this PhD project is to explore the potential of using 2nd life batteries for BESS in power systems. More specifically, the aim is to develop methods to derive owner-optimal composition and operation of one, or several BESS with different locations, for the most important potential grid applications.