As the time-honored saying goes (that we just made up), old Chevy Volt batteries don’t die, they just … well General Motors is working on that, and one solution is re-use as renewable energy storage.
That’s what the automaker has done in an experimental but functional showcase at its Milford Proving Grounds in Michigan, where it will help supply power to its new Enterprise Data Center.
Chevrolet’s Volts have each been equipped with 435-pound-plus lithium-ion batteries sized from 16.0-17.1 kilowatt-hours. With over 93,000 Volts and Ampera variants sold globally since 2011, the question of what to do with those packs as they go out of service is becoming more relevant.
Along with the batteries grouped together in a neat logo’d box, GM tied in a 74-kilowatt ground-mount solar array with two 2-kilowatt wind turbines to generate enough renewable power to service the office building and lighting for the adjacent parking lot.
That’s enough renewable power for approximately 100 mWh of annual energy, or roughly the energy used by 12 average homes, and GM notes it’s made possible because even “used” Volt batteries, while beneath as-new spec, do provide energy storage.
“Even after the battery has reached the end of its useful life in a Chevrolet Volt, up to 80 percent of its storage capacity remains,” said Pablo Valencia, senior manager, Battery Life Cycle Management.
“This secondary use application extends its life, while delivering waste reduction and economic benefits on an industrial scale.”
This demonstration project does of course cast a nice green hue on the automaker, and in the process helped it attain LEED Gold certification from the U.S. Green Building Council, but where it’s all going may have further pragmatic importance.
As Tesla and subsequently Mercedes are showing, there is a budding market for on-site energy storage for car makers to tap into. The Tesla Powerwall and Mercedes-Benz products use new li-ion batteries but the used and still viable batteries are being tested.
GM says it’s a “living lab” to gain a clearer grasp of how the battery redistributes energy at this scale. It and partners are working to validate and test systems for other commercial and non-commercial uses, said Valencia.
“This system is ideal for commercial use because a business can derive full functionality from an existing battery while reducing upfront costs through this reuse,” he said.