Old EV Batteries

How Old EV Batteries are Perfect for Energy Storage

How Old EV Batteries are Perfect for Energy Storage

Foreword by Ian Thompson, Editor

What does the future hold for home energy efficiency? Can we envision a scenario where most homes are genuinely off-grid? Is it possible to sever the umbilical cord that ties us to the grid? I recently had a builder scoff at this idea, dubbing it a “hippie’s dream.” But, is it? Truly?

The automotive industry appears light-years ahead of the general building industry. Who could have predicted we’d be cruising in electric vehicles significantly more efficient than their petrol and diesel counterparts? These EVs are not only more eco-friendly in usage (though not necessarily in production), but we can also plug them into our homes to gain electricity but also use the stored energy from the vehicle to power our homes.

Imagine another scenario: driving to work, plugging your car into the building’s solar array, fully charging your vehicle, then returning home. You plug your car into your house, using the stored energy to cook dinner, watch TV etc. – and still have enough battery power to drive back to work the next morning. Sounds perfect, doesn’t it? However, this utopian vision hinges on our companies’ and building owners’ willingness to invest in renewable energy hardware, which, let’s face it, is a stretch for many, at least in the next decade or so.

For a long time, I’ve pondered how to break free from the grip of major utility providers and large, inefficient, revenue-driven councils. Their exorbitant rates and nonsensical infrastructure projects baffle me. I’ve made some progress, with various renewable energy sources powering my home, but I’m still hesitant to invest in prohibitively expensive storage batteries. But what if we considered repurposing car batteries when they’re no longer efficient for vehicular use, yet still have ample capacity to power our homes?

In this video, our renewable energy expert, Matt Ferrell, tackles this very topic. He initially discusses large-scale applications, but also leaves room for individual home use.

If you’re interested in smart ways to repurpose EV batteries, don’t miss this rigorously researched analysis. Let’s gear up for the impending wave of spent batteries.

And now, over to Matt.

Video Transcript

It’s been nice to see the growing popularity of electric vehicles these last few years, but EVs need batteries, and batteries don’t last forever. In fact, the first generation of EV batteries are already dying, and there’s an absolute dead battery typhoon coming. Lithium battery recycling is improving, but it’s still far from where it needs to be. Luckily, there’s another option that’s pretty simple. Just take those used batteries and repurpose them for less demanding large-scale energy storage. That’s exactly what’s happening at a recently opened 25 MWh grid-scale energy storage system in California.

But if these batteries are “dead,” how are they able to bring new life to renewable energy storage? I’m Matt Ferrell … welcome to Undecided.

If you can get quality grid-scale storage from just daisy chaining a bunch of car batteries together, then why aren’t they everywhere? And why would someone string 1,300 “dead” car batteries together in the first place? The reasons might surprise you, but this weird solution will make sense in a minute.

California is famously sunny and warm. To beat the heat, many Californians rely on air conditioning. As you might expect this leads to a significant power draw during the day, which is not a huge problem as that’s when renewables are generally most productive. But the draw actually climbs even higher at night when people return to their homes, which is unfortunately right when renewables like solar start to fall off. So how does the most populous state handle these massive energy swings? Right now, the answer is “peaker plants,” whose purpose – as you can probably guess from their name – is to supply not-quite-emergency power during these peak times.

“Great, problem solved!” right? Well, not quite because peaker plants get their power from natural gas. To be clear, natural gas isn’t as bad as oil or coal, but it’s still a fossil fuel that gets burned and puts carbon into our atmosphere. To quote the California Energy Commission Chair, Dan Hochschild, “Peaker power plants are the most expensive, least efficient, and most polluting part of our fleet.”

Sure would be great if they could switch to renewables, but that brings us to our next problem, one that viewers of this channel will be all too familiar with: effective energy storage. It’s why I’m obsessed with this topic. Luckily, electric vehicles are helping with decarbonization, just in their way. They’ve been with us for years now and are becoming increasingly affordable and popular. For perspective, back in 2012, just 120,000 electric cars were sold worldwide. In 2021, more than that are sold each week. Unfortunately, all those cars are powered by batteries that will need to be replaced eventually.

What the heck are we going to do with all of those batteries!? Well, reduce, reuse, recycle, right? We don’t want to see a reduction in electric cars and their batteries for plenty of reasons, so let’s not reduce here. Lithium battery recycling has made some great strides recently, with groups like Redwood Materials, Recyclico, and Li-Cycle working hard to make this process easier and more efficient. But the coming flood of used batteries, (or battery flood, which is coincidentally, the name of my new metal band) is a challenge too big for recycling to handle alone.

That leaves us with reuse, but how can we reuse “dead” car batteries? This brings us back to B2U Storage Solutions and their seemingly super simple answer to all these issues. They’ve taken approximately 1,300 used Nissan and Honda batteries and strung them together to form the SEPV Sierra hybrid solar storage facility. Based in Lancaster, California this 25MWh facility is likely the largest, fully operational “second-life” battery storage facility on planet earth.

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But if these old EV batteries are dead, how does this even work? Has B2U discovered some sort of battery necromancy? (Actually, Battery Necromancy is the name of my new metal band) Nope, way simpler than that.

But before we get into this interesting approach to battery storage, there’s another bit of tech that you can pair with battery storage for yourself today … and that’s from today’s sponsor, BougeRV. I’ve talked about portable and modular batteries that are perfect for on-the-go power backup and use, but pairing those batteries with solar takes things to a whole new level. The problem with most portable solar panels though is that they’re large, heavy, and can be fragile.

BougeRV’s 100W PASO CIGS Solar Panel (CIGS stands for copper indium gallium selenide) solves those problems because it folds down to something that can fit into a laptop-sized carry bag… and it’s virtually unbreakable. Using and installing them couldn’t be easier. Just open the pack and unfold. There are 4 holes, so you can tie it down to any hanger or just lay it out on any flat surface. If you’re into camping or like traveling around in an RV, this is a great addition to any battery storage. Even if you don’t go camping a lot, this is a great addition for emergency battery backup at home. You can top up your portable battery if the grid is down to keep things going even longer. If you want an incredibly flexible, durable, and waterproof solar panel that can go just about anywhere, check out the link in description and get 15% off! Thanks again to BougeRV and to all of you for supporting the channel.

Now back to B2U’s simple approach. If you own a rechargeable device (I’m willing to bet you do), you’re aware that their ability to hold a charge diminishes over time. The reasons for this are a little complicated, for more information check out some of our videos on batteries. But suffice to say, Li-ion batteries remain the gold-standard in consumer goods, especially in EVs, for plenty of reasons. This includes their solid capacity and longevity, their good energy-to-weight ratio, power density, swift charge/discharge times, affordability, reliability, and so on.

But life for a lithium-ion battery in an EV is pretty demanding, and once a battery starts to go, usually when it’s only able to hold around 70 to 80% of its charge, it can no longer live up to these standards and should be replaced. But hey, a battery’s life doesn’t end at around 80%, there’s still plenty of good times left in its golden years, just maybe not inside a brand new Tesla. Stationary, intermittent renewable storage is actually a great home for aging batteries because in this application they’re allowed to charge and release energy more slowly, and the cycling needs and other demands are generally less intense than in a high-performance vehicle. But their efficiency, reliability, and safety are still appreciated. This is backed up by a 2019 McKinsey sustainability report, which found that even after 10 years, an EV battery can be reused in markets that need stationary energy storage with less frequent cycling.

Again, back to B2U, who saw the coming battery-pocalypse (okay, no this is the name of my metal band). Anyway, B2U put 2-and-2 together, and voila, turned these mountains of EV batteries into a grid-scale storage facility. So, I know I said the solution was simple, but it’s not quite as easy as hooking a bunch of old car batteries up to some solar panels in the desert. There are some unresolved challenges to this, which we’ll get to in a minute, but more challenges have been solved than not. One such challenge is the batteries themselves. With 1,300 batteries, all of different ages, from different makes and models of cars, in different states of degradation … there’s a lot of variables to manage. Especially since we have literal tons of batteries working in sequence, and we don’t want the older or weaker ones to slow the system down.

There’s also some safety concerns. Lithium batteries are notoriously (if, in actuality, very rarely) susceptible to overheating leading to dramatic cases of thermal runaway. Stacking a bunch of these batteries together in parallel strings in an especially warm and sunny state might seem like a disaster waiting to happen. It’s here that B2U’s biggest innovation comes into the picture. Their software, in tandem with their cabinet controllers, monitors all those battery variables during charge and discharge cycles. It can connect and disconnect the batteries as needed, allowing the older batteries to take a break before they drag down the performance of their buddies. B2U CEO Freeman Hall claims that “this approach enables our system to achieve efficient energy yield despite the variance in capacity inherent in second-life batteries. On the safety front, B2U’s EPS cabinet controllers monitor the health of individual batteries and flag situations where there are potential problems that can affect future performance. The operators can also set strict safety parameters, and if any battery deviates from these guard rails, the pack is automatically disconnected, allowing it to cool down and be dealt with rather than risking disaster.

This brings us to another innovation from B2U. Lithium car batteries are usually made up of thousands of roughly double-A-sized batteries, literally glued together. Close to 7,000 of them for a Tesla. Part of the reason it can be challenging to recycle or repurpose these batteries is because you normally have to break apart each pack to get to the individual cells. But not so for the Sierra facility. Their cabinets are designed to accept packs as they are, instead of having to jailbreak each individual cell, which saves them time and money and allows replacement batteries to easily be tagged in when the time comes. Combined with their cabinet controllers and software designed to translate commands across different battery makes, means they’ve made the process of reusing batteries in grid-scale storage much cheaper – an estimated 40% cheaper. Hall claims it costs less than $200 per kilowatt hour to install, which is well below the norm for a lithium-ion storage plant. For context, a National Renewable Energy Lab study put the cost for a similar facility in 2023 at around $283 per KWH. And they didn’t project costs to dip below that $200 per KWH until 2030! And speaking of money, the EPS controller doesn’t just monitor the batteries, it monitors the market for the best deals too. By taking advantage of both predictable daily price shifts and unexpected price hikes, it automates bids and sends them directly to the California grid. Tesla has similar functionality with their Megapack installations. Essentially, it collects energy while the sun is shining, then when people get home at night it sells that energy to the grid when it’s most desired and valuable. A sort of “buy low, sell high” arbitrage strategy that has generated over $1 million in revenue for B2U in 2022. The fact that they’ve already proven they’re financially successful probably makes them more appealing to investors and lawmakers, which hopefully means more plants like this in the future.

The SEPV plant has already proven that it’s an affordable, reliable, and effective grid-scale storage solution for solar energy. It offers a home for older batteries and seems ready and able to start replacing those gas-burning peaker plants. That all sounds incredible, so what’s the catch? There’s always a catch. And yes, as we alluded to earlier, some challenges do remain. B2U is mostly working with Nissan and Honda, so their system is largely designed around dimensions and shapes that work with those. If the batteries deviate from the standard shape, it might diminish some of the benefits of B2U’s ‘plug n play’ system. Though, at least on the software side, tests on the Chevy’s Bolt and Tesla’s Model 3 show the EPS system can communicate with just about any EV battery model. Ironically, the biggest issue is that the system is small. 25 megawatt hours of storage is a great start, but for context, peaker plants like the Hanford and Henrietta plants have 95 megawatt capacities each. We’re going to need a lot more (or bigger) SEPV storage facilities and accompanying renewable power plants if we want to dump those polluting peaker plants.

But all in all these are some pretty minor hurdles to jump. Ultimately, B2U’s Sierra SEPV facility shows that we don’t have to wait for the next big battery paradigm shift to “up” our renewable energy storage game. The technology is already here, it’s safe, it works well, and it’s relatively inexpensive. As EVs become more popular and age there’s going to be no shortage of supplies. Plus, it’s not like the sun is going anywhere for another 5 billion years either. Speaking of which … B2U’s set-up isn’t limited to solar storage. There’s a lot of wind power in California, Texas, and other states that could really benefit from a similar storage solution. Hopefully, we will see more plants like this sooner rather than later.

So what do you think? Jump into the comments and let me know. And be sure to check out my follow-up podcast Still TBD where we’ll be discussing some of your feedback. Thanks to all of my patrons, who get ad-free versions of every video. And thanks to all of you for watching. I’ll see you in the next one.