One of the big arguments against electric vehicles is the environmental cost of the batteries. Yes, EV production does have a higher environmental impact than making a gas-powered vehicle, but in most cases the environmental impact of operating it for a decade or more is far less than the gas car. The other side of the environmental cost of the battery pack comes after the pack wears out, with a need to reuse the pack in some way, or recycle it if it can’t be reused.
What most critics don’t know is just how much reuse is possible. By the time a battery pack loses too much range to be useful, the overall capacity is still around 50-60% of the original. For a car, that lost energy density is unacceptable, but for a stationary installation, the pack and/or its battery cells can still do a lot of things. The cells could be used like a Tesla Powerwall, powering a home at night from the solar energy that rooftop panels collect during the day or helping get the family through power outages.
Only after it loses its ability to do that kind of work (perhaps another decade) would the battery cells need to be recycled, which is another thing that’s ramping up.
Saying that we want to reuse battery cells and then recycle them and actually doing that are two separate things, though. It’s easy to just let a car rot in a junkyard, or do something else that doesn’t involve recycling the pack. To make reuse a reality, someone needs to pioneer the methods of reuse and learn what the ups and downs of that are.
Fortunately, Volkswagen recently did just that.
Reusing MEB Battery Packs For EV Charging Stations
Using battery packs at charging stations is nothing new. It’s a great way to save costs on utility demand fees (the charge based on how much power you use at most during a month). To support the infrastructure and generating capacity needed for something big like EV charging, utilities charge big bucks, from hundreds to thousands of dollars monthly, to support that. If you can take a smaller trickle of power from the power company all day and deliver high power to cars in a burst, you can save a lot of money and put less stress on the grid.
Tesla has been doing that for years, and so have other charging providers like Electrify America (a Volkswagen subsidiary). Now, Volkswagen is testing doing this, but with used batteries from Volkswagen vehicles instead of having new batteries made.
“Reusing batteries is important for the future and it’s closely linked to the acceleration in the trend toward electric mobility. With the power storage container, Volkswagen Sachsen is demonstrating a practical, cost-effective and useful case to enable cell modules at the end of their service lives to have a second life.” Said Karen Kutzner, managing director for finance and controlling at Volkswagen Sachsen “This automotive power bank could be used wherever the capacity of the grid connection is too low but there is demand for powerful charging infrastructure. Innovative ideas like this could provide renewed impetus for the critical buildup of fast-charging infrastructure.”
What the company did was take used cells from its ID.3 and ID.4 vehicles, constructing a 570 kWh stationary storage pack. This pack then powers four charging stalls, with a maximum output of 150 kW (or eight cars each pulling 75 kW). Before putting in the batteries, the installation area could only support 11 kW Level 2 EV charging, but by trickling that level of power into the big, big battery pack, they can charge a number of vehicles a day at high rates without having to upgrade the utility connection.
Preparing the local grid to pull 600 kW from it (150 kW times four) usually take a lot of work and expense. Instead of getting normal 240-volt or three-phase commercial power, DC fast chargers need a transformer station to get power from higher-voltage power lines nearby. A power company passes that cost right down to the station owner, which massively raises not only the installation cost, but monthly expenses (in the form of demand charges).
Volkswagen was able to put in a four-stall fast charging station next to its Zwickau plant for a fraction of the normal cost, but cost isn’t the only factor that makes battery storage at charging stations a great idea. In many cases, especially in the developing world, there just isn’t a grid that can supply that kind of power. The cost would not only be enormous, but in many cases basically impossible. By adding battery storage, the energy from charging can come from not only the grid, but from renewables on site if needed, to support EV charging over the whole day.
While there was little doubt that used packs would work for this, Volkswagen found in its trial that no unexpected “gotchas” came up, and that it really can be done.
This Will Be Important In A Few Years
Sadly, we’re already seeing cars that have packs ready to be replaced. Not only do we see this happening to cars like the Nissan LEAF with no liquid cooling, but we’re seeing Teslas with age-related battery pack issues. Places like Gruber Motors are figuring out how to keep aging Teslas on the road, but in many cases people won’t think it’s worth it to repair them, or they’ll just do what seems simple and buy a whole new pack from the manufacturer to be 100% sure.
As EV adoption increases, there will be many old packs that we’ll need to figure out what to do with. In most cases, they’ll still hold a lot of energy, just not enough to be suitable for automotive use. By having procedures and even a “triage” method for incoming used and broken battery packs established in the industry, battery packs will go to their best possible use instead of rotting somewhere, or ending up a danger to the environment.
While this is happening, we’ll also need many new charging stations for people, so it’s really a match made in heaven. Last generation EVs (or what’s left of them) will help the next generation get down the road. Being able to do that will be a great outcome.
Featured image by Volkswagen.
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