Used EV Batteries Get New Life Powering the Grid

 In EV Charging, EV Industry, Vehicle Research

It’s not just your imagination or wishful thinking. With nearly 2 million on the road today, there’s been a surge in EV sales and their numbers are growing. In fact, 550,000 EVs were sold worldwide last year alone.

What’s more, EV batteries are brawnier than people may have thought.

A study using a Nissan LEAF by the Department of Energy’s Lawrence Berkeley National Laboratory found that even at 20 percent fade in capacity, EV batteries still met the needs of 85 percent of drivers. At 50 percent battery degradation, more than half of EV drivers could still get around just fine.

But down the road, there’s going to be a surplus of sturdy used EV batteries with plenty of power to spare. Imagine all that juice, just waiting to be harnessed in a handy, eco-friendly way.

“Our analysis showed that the battery pack we studied, the Nissan LEAF, has a large margin of extra power capability.” Samveg Saxena, research scientist at Lawrence Berkeley National Laboratory

What can you do with a used EV battery?

One of the more popular suggestions being bandied about with regards to repurposing used EV batteries is to incorporate them into grid-connected energy storage.

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With the push to integrate more sustainable power networks such as solar and wind farms into the grid, an EV battery mix could provide some badly needed stability.

Let’s crunch some numbers. A second-life battery with 75 percent of its original capacity can store and dispatch up to 850 megawatt hours of electricity. Bear in mind that one megawatt hour equals the power used by 330 homes over one hour. Imagine the electricity savings for home owners!

BMW Rolls Out Massive i3-Powered Energy Storage System

BMW Rolls Out Massive i3-Powered Energy Storage System

Research by Bloomberg New Energy Finance (BNEF) expects a cumulative 95 gigawatt hours of total second-life battery capacity to be available by 2025. One third, or 26 gigawatt hours, would be suitable for stationary energy storage. And by 2025, the market analysts at IHS Markit expect global energy storage capacity to reach 21 gigawatt hours. So adding on those 25 gigawatt hours of cheap storage would be a really big freaking deal.

BNEF indicates that by 2018, used EV batteries could cost only $49 per usable kilowatt hour to repurpose. That’s a downright bargain, compared to the new stationary battery price of $300 per kilowatt hour.

It would also serve to further expand the EV market, as owners factor in the resale value of batteries. For example, a used 24 kilowatt hour Nissan LEAF battery could net the owner up to $2,400, while a used 85 kilowatt hour Tesla Model S battery could be worth up to $8,500. That would completely redefine the meaning of “residual value” for many motorists.

Excited yet? The automakers are.

Already, many automakers are pumped at the prospect of squeezing more life out of EV batteries.

Daimler Benz has put 1,000 battery systems from second generation electric smartfor two cars into battery storage in Lünen, Westphalia. The first power units are already in the grid, and by the end of this year, that 13 megawatt hour battery storage will be at the disposal of the German energy market.

General Motors is running a test program with used Chevrolet Volt batteries to help power their GM Enterprise Data Centre. Nissan is working with Sumitomo and Eaton to launch a stationary storage product composed of a stack of old LEAF battery modules. BMW is working with Pacific Gas and Electric, introducing a stationary storage that will ultimately involve second-life batteries.

Toyota is powering an off-grid solar system backed up by 85 kilowatt hours of used battery storage at the remote Lamar Buffalo Ranch field campus in Yellowstone National Park. It combines solar power generation with re-used Camry Hybrid battery packs.

At the Lamar Buffalo Ranch in Yellowstone National Park, re-used Camry Hybrid batteries provide 85 kilowatt hours of energy storage in addition to solar power.

At the Lamar Buffalo Ranch in Yellowstone National Park, re-used Camry Hybrid batteries provide 85 kilowatt hours of energy storage in addition to solar power.

And Tesla? At his gigafactory in Nevada, Mr. Musk is doing his own recycling, cannibalizing key materials like lithium, cobalt and nickel into new Tesla batteries.

There are more initiatives from academia. Here in Canada, Dalhousie University in Nova Scotia is promoting a “fully funded” opportunity for a grad student in “control methods for optimal operation of a mixed battery array.” Their Renewable Energy Storage lab already has EV batteries totalling several hundred kilowatt hours. Work completed by undergrad students so far indicates good performance.

In April 2014, UCLA Law and Berkeley Law Schools hosted a discussion group between automakers, utilities reps, energy storage developers, business leads and public officials. Talks focused on a vision to develop a market for second-life battery deployment to help California achieve its aggressive renewable energy goals. And the UC San Diego is testing second-life EV batteries to power its microgrid.

While prospects are bullish, there are barriers for preloved batteries.

Although EV batteries have come a long way since 2008, they still have lower energy density, so automakers are reluctant to warranty them.

EV batteries come in different shapes and sizes, and are used in disparate climates by all kinds of drivers with various stressors. There’s a need to mix and match them – like the Dalhousie initiatives – to get optimal consistent performance. This needs to be a safe, reliable, insurable and bankable system.

Day trader Jason Hughes works on running electrical wiring to junction boxes used to convert captured solar energy to store in Tesla Motors Inc. batteries in Hickory, North Carolina.

Day trader Jason Hughes works on running electrical wiring to junction boxes used to convert captured solar energy to store in Tesla Motors Inc. batteries in Hickory, North Carolina.
Photographer: Chris Keane/Bloomberg

Enter Underwriters Laboratories (UL), who want to create a standard for second-life batteries that addresses performance and safety issues. They’re in the midst of doing a thorough, rigorous assessment to address potential safety risks.

There’s still no data on how used EV batteries may impact energy storage, given that they pack a lot of energy into a small footprint. Above all, there’s a need to ensure a safe infrastructure and identify a good common set of expectations.

UL plans to work with a broad community of stakeholders, such as national laboratories, academia, industry experts and the user community. They’re developing an internal testing program adopted by corporations, which will provide a signal of confidence to the end consumer. It’s never too early to start, since it will take time to get it right – assembling a team of experts, develop and refine the right testing protocols.

And by 2017, UL expects to have a standard in place, so that testing can officially begin. Their goal is to convince bankers and insurers that potentially millions of used EV batteries and thousands of megawatts of storage capacity are safe, and can be financed for on-site and grid level applications.

Charging ahead with used EV batteries as a force of good.

In short, EV batteries have huge potential to lock down low cost energy storage to consumers without compromising the infrastructure. So for the interim – unless proven otherwise, it’s okay to be bullish on these batteries.

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  • DaleDe

    This it timely, although repurposing these batteries have been going on for quite a while in peoples homes as evening/night time use for solar cells, among the savvy allowing them to be off the grid or less dependent. However if the deterioration is not even across the cells you are likely to get on or two of weak cells that will trigger the “check engine” light. I had this happen on my old Prius (2004), forcing you to replace the battery even if it is mostly good.