Putting Used EV Batteries to Work
One of the most frequently asked questions about EV batteries is: what happens to them after they’re used up? Well, first of all, given what we know about battery degradation, most EV batteries will last for 10 years or more without a significant amount of degradation (early Nissan Leafs aside), which means that most EV batteries will last the life of the car, or more. When a car does reach the end of its life, batteries can be recycled or re-used – and some of the ways they can be re-used are particularly innovative and economical.
How Can Battery Storage Help Save Money?
Electric car batteries, which have to provide enough power to move thousands of pounds of metal around, and sustain high-speed charging and discharging, store so much energy that they can power a house for days. If you have a house with solar panels, one or two car-sized batteries can enable you to essentially live off the grid, providing enough power for all your home’s electricity needs – or at least helping you save a big chunk of money on your electricity bill. This is the concept behind Tesla’s PowerWall and similar battery-storage systems.
Even if you don’t have solar panels or a way to charge the batteries from a source other than the grid, battery storage units and leveraging used-up EV batteries can help you save on energy because they can be programmed to charge when electricity is cheapest; you can then run your appliances off the stored energy as normal. In some regions, off-peak electricity rates can be as low as 10 percent of on-peak electricity rates – meaning savings of hundreds of dollars a month for households that consume a lot of electricity.
Porsche’s Battery Storage Facility Powers its Factory
If an EV battery can power your house, saving on energy costs and making your home more efficient, imagine what you could do with hundreds of EV batteries. Well, that’s exactly what Porsche has done at its factory in Leipzig, Germany. In a compound the size of two basketball courts, and using 4,400 battery modules, Porsche has built a massive energy storage system that uses batteries from pre-production vehicles and prototypes that have been crushed – putting the batteries to use as a tool to store energy and provide economical, emissions-free power for the massive factory.
Porsche’s battery storage project exemplifies how used EV batteries can not only help big businesses operate more sustainably, but also lower costs and improve efficiency. The site makes the factory more economical to operate, and helps make it more self-sufficient. Porsche says it hopes to gain insights from the project in order to be able to equip other facilities within the company with similar systems and capabilities. Power storage units give EV batteries, such as those from the Taycan, a second home after they’ve been exhausted in test vehicles, one in which they will have decades of useful life before they need to be recycled.
The specs of Porsche’s battery storage unit in Leipzig are pretty impressive. The 4,400 batteries together create capacity for 10 megawatt-hours to be stored, and it can provide up to 5 megawatts of energy; the storage system can even be operated at up to 20 percent “overload” for short bursts of time. Four separate storage units contain 1,100 batteries, and each of them are connected to an inverter and a transformer. If a battery does fail, it is easy to swap one out and replace it for another unit from a used-up test car.
How Does Battery Storage Work with Solar?
As for where it gets its power from, a large percentage of the electricity for the system is generated by the solar panels already mounted on the roof of the gigantic car factory, which can generate up to 9.4 megawatts.
The batteries can also draw power from the grid – letting them contribute to “peak shaving” during the factory’s most energy-intensive periods. Peak shaving means that the factory draws power from the grid, but also from the battery storage system – significantly “shaving” its electricity costs. Because the energy stored within the battery system is used and replenished far more gradually in a static setting than in a car – which discharges rapidly every time you accelerate, and is often charged rapidly as well – batteries can have a very long life when part of a storage system.
On the supply side, installations like Porsche’s can not only reduce dependence on the grid, but they can also reduce the need to expand the electrical grid to meet increasing demand, as more businesses and individual consumers electrify their heating and ventilation systems and plug in more electrical devices.
The Future of Battery Storage Systems
Flexible, and easily controllable, energy storage systems like Porsche’s in Leipzig can also be used to store energy and sell it back to the grid, when the grid needs it most. For businesses and personal users, battery storage can prove to have financial benefits even beyond saving money on energy bills.
Over time, as EVs become more common, and as EVs reach the end of their useful lives, you can expect to see more and more innovative solutions for reusing EV batteries.
