Unlocking the Potential of Electric Vehicle Batteries along with Energy Storage

Together electric vehicle batteries and solar power are being evaluated to help improve the ability to store energy and improve the functionality of the grid. The goal is to reduce the need for additional power production and shrink landfill waste.

The news of electric vehicle (EV) reuse is gaining in popularity because there are more than one million electric vehicles navigating the world’s roads as of 2015. In the next year, the batteries from the first wave of electric motor vehicles will come to the end of their automotive lifecycle and warranties.

While the concept of refurbishing a product is not new, working to a larger scale has proven to be a challenge. Each battery needs to be evaluated individually because each one has been exposed to different charging and discharging conditions through its lifetime. However, these batteries are an exciting opportunity to help improve renewable energy, specifically, energy storage.

EV batteries may provide storage capacity after they’re removed from vehicles and reclaimed for a “second life” as stationary power sources. This could reduce the need for additional power production and shrink landfill waste.

Solar energy may benefit from battery integration, which can help owners hedge against potential intermittencies in solar electricity supply because they can store surplus energy and add capacity and flexibility. Because of the added capability and resilience, many states have incentive programs to support expanded energy storage infrastructure. As the population of available EV batteries grows, they can play a key role in the expansion of energy storage.

UL Develops New Safety Standard

UL is working with input from automakers, battery reclaimers, electric utilities and academic institutions to develop the safety standard UL 1974. The standard will provide users with the confidence that an EV battery will function effectively as an energy storage device in a residence, commercial facility, or connection within a microgrid (utility grid).

A123 Prismatic CellsUL has been doing extensive battery research for more than a decade, and leveraging that into the company’s standards, product testing and certification of battery technologies. However, the testing of EV batteries for reuse is significantly different than their usual approach. The biggest difference in the development of this standard from others is that instead of certifying an end-product to a requirement, this is testing and certifying the conversion of a product that is already in use.

Batteries are classified for their “state of health” through initial screening tests that consider all different types of batteries and types of technologies. Then, “bad” EV cells are weeded out through additional testing processes, determining what part of a battery pack will be swapped out, what will be replaced, and what will be disposed.

The real challenge is finding a method of evaluation for EV batteries that is nondestructive, otherwise UL’s testing would destroy the battery that this process has been built around. UL is still establishing the finalized nondestructive testing criteria for the UL 1974 standard, but we know infrared imaging or similar tests can provide precise electrical evaluation of the cells, allowing us to evaluate an individual battery’s ‘health’ to see if it is capable of being repurposed or not.

While large-scale deployments of reused EV batteries have not been established yet, UL has partnered with those at the forefront of its development. Currently, UL is working with many key industry leaders. These include the University of California at San Diego, which has a pilot program to make the university among the first to integrate second-life batteries into a campus microgrid.

Researching both EV batteries and solar power should help develop large scale incentives and natural connections that bring immediacy and reliability for the grid. This technology will make energy more affordable and make it more accessible to residential areas.

Author:  Ken Boyce,  UL