The number of electric vehicles (EVs) on roads is growing rapidly. EV batteries today, almost exclusively lithium-ion based, can last about 10 years before they can no longer provide the required performance such as power and range. They cost heavily in both production and recycling. So economically dealing with retired EV batteries is an important topic. It is estimated that the first huge wave of EV battery retirement will hit in 2025, and more retired batteries will be available each year thereafter.
On the other hand, renewable energy, such as solar photovoltaic (PV) and wind, also enjoy a high rate of penetration. To buffer the volatile nature of the energy output of renewable energy systems, battery energy storage systems (BESSs) are frequently incorporated to balance out the variability in power generation, efficiently manage the dynamics of demand and supply, mitigate the potential failure of the grid due to over generation, provide power during a power outage, and enable cost savings by shifting the peak use and reduce demand charge. However, the high cost of new batteries in renewable and grid storage systems is a major concern for potential home and business owners.
Batteries in EVs degrade gradually over the lifetime of the vehicle and will reach the point that it is no longer able to provide the required performance, such as range and acceleration. Second-life EV batteries include not only the batteries that are discarded from EVs due to degraded conditions; but also in-warranty replacements; road accidents; test vehicle batteries; and unsold batteries. Second-life EV batteries, though no longer roadworthy in the vehicle, still have considerable capacity for renewable energy and smart grid applications where the requirement for energy and power density is not as stringent in vehicles. The use of second-life EV batteries in grid BESS extends the life cycle of batteries after their first life in EVs, improves the environment, reduces EV ownership cost by selling them for second-life use, and reduces the cost of BESS in renewable energy systems.
However, there are a number of barriers to overcome in the deployment of second-life EV batteries, including how to properly remove them from vehicles, transport, store, test, and select second-life batteries for storage applications; how to quickly, and accurately identify the battery health conditions of every cell before and after deployment in grid storage; how to dynamically manage them so as to minimize degradation and optimize usage; and how to meet various standards related to fire hazardous mitigation/prevention, certification, permit, and safety.
This talk will holistically look at these issues and address how second-life EV batteries can be used in renewable energy and smart grid applications. The talk will include storage system design, battery management, battery balancing, size optimization, and system control and optimization for demand charge management and peak shaving. We will also look at the various testing requirements for identifying the conditions of used EV batteries. The aging mechanism of second-life EV batteries will be presented. Various topologies for storage applications, safety, standard, and permit-related issues, will also be discussed.
Speaker(s): Chris Mi,
Agenda:
6 pm – Introductions, pizza, salad, coffee, soda pop, social interactions (you can arrive earlier if you like)
6:30 pm – Actual Talk
7:30 pm – Q&A, open discussion
8:00 pm – Formal thanks and event end
Room: 1011, Bldg: IAVS, 4901 Evergreen Road, Dearborn, Michigan, United States, 48128