Electric vehicles held the spotlight at this week's Frankfort Auto Show, with Volkswagon, Daimler and Renault all announcing new EVs and Mercedes introducing a new plug-in hybrid. Along with Nissan's announcement that it intends to sell 150,000 Leaf electric cars in the United States by 2012, the news is raising high hopes for an electric auto industry on the rise.
But as this transportation technology hits the market in coming years, it will raise an interesting question for consumers: What do we do with that battery pack after it stops holding enough charge to power a car?
The auto industry aims to provide batteries that will last for the lifespan of the car—at least 10 to 15 years. But some experts predict that consumers will opt to replace their EV batteries with newer, better ones as the performance degrades.
"When we see some deterioration—when we've lost 20% of the battery's capability in terms of power and energy content—then the question is, will customers accept that kind of deterioration? That's pretty much our standard for functional end-of-life," said Ted Miller, senior manager of energy storage strategy and research for Ford Motors.
So what exactly will happen to "spent" EV battery packs?
Battery recyclers are beginning to develop their capability to process lithium-ion batteries in order to meet future demand.
Using a $9.5 million grant awarded last month by the Department of Energy, the California-based Toxco has plans to build an advanced lithium battery recycling facility at its existing Lancaster, Ohio, location. Toxco already operates North America's only lithium battery recycling plant in British Columbia and recycles nickel metal hydride batteries—the type used in Toyota's Prius hybrid cars—at its Lancaster plant.
Looking even further into the future, EV owners may have other options to consider before tossing used battery packs on the recycling heap.
Even after a battery loses its value for powering an EV, it's far from juiced out—it may still have the capacity for some promising alternative applications.
Car manufacturers and utilities have begun to consider the possibility of re-using EV batteries, which could serve as storage devices in individual homes or in larger looped storage banks. The old batteries would reduce strain on the power grid during peak hours and provide back-up power for homeowners in the event of grid failures.
It sounds promising, but the potential storage applications of old EV batteries aren't in practice yet. With so few EVs on the market, there's not enough technology to demonstrate the system at scale. In turn, that means there's not enough incentive just yet for utilities to buy in.
"We'd obviously love to say these batteries have some residual value, that they'll have some applications at end of life," Miller said. "But we don't have many batteries to even experiment with. That's the next phase. We're just trying to get these into cars for the first time."
EV battery storage solutions right now also lack the institutional mechanisms to bring them into widespread use. According to Miller, the industry will need a way to validate that batteries are suitable for other applications once they've served their purpose in electric cars.
"Somebody needs to make a business of this—of re-certifying batteries for other applications, evaluating them, screening them, reconfiguring them, pulling out the weak portions and salvaging the useful ones. And there's a cost associated with that," he said.
With the future for end-of-life EV batteries largely uncertain, many experts point to the ways advanced batteries could be used during their lifetime.
Ron Freund, chairman of the Electric Auto Association, explained:
"Even when a battery is being used in a vehicle, that vehicle is not being driven 22 hours out of the day. Most of the time it's sitting idle, and during this time it's underutilized."
If enough vehicles were plugged into the grid, their batteries could help supply power during the few minutes of peak time each day when electricity demand puts a strain on available supply. Now, utilities turn to dirty power generators to pick up that slack—but using EV batteries as a power reserve for frequency regulation would be cheaper, cleaner, and would benefit the consumer as well.
"As a homeowner I could get a few hundred dollars a month to let them use my batteries for less than an hour total per day," Freund said. "It's conceptually not rocket science."
But the familiar barriers mean this vehicle-to-grid (V2G) connection model also has a ways to go before becoming reality. First and foremost, the realization of the V2G vision would require updated smart grid technology that could handle increased power capacity from plugged-in vehicles. It would also require a central command post or aggregator to control the flow of power from grid-connected EVs.
"Any change to the infrastructure means expenses for the utilities. And they don't want to rush something that's expensive for them," Freund said. "The infrastructure needs to be boosted, protocols and standards need to be set, and that will take time."
Car makers have some time to figure out the logistics. While President Obama has called for 1 million PHEVs on the road by 2015, sales are only now beginning to grow, so it will likely be over a decade before the country finds itself with a significant number of used batteries on its hands.