When a Chevrolet Volt battery is used up and can’t power the car any longer, it still has some juice left. That juice can be used to create electricity. Specifically, the juice from five Volt extended-range electric car batteries is being used to help power the new General Motors data center at its Milford Proving Ground in Milford, Michigan.
The Volt draws power from a band of energy in the battery pack, and that leaves a lot of juice left over to be used as electricity. Up to 80 percent of the battery’s storage capacity remains after it is no longer useful in a Volt.
“The Volt batteries are tied to the solar array and wind turbines, storing power during times of generation and powering the facility overnight or when renewable resources are not generating,” Rob Threlkeld, global manager of renewable energy for GM, told TriplePundit.
“The power generated by the solar array and wind turbines offsets [all of the power] used by the administration building tied to GM’s new data center in Milford.”
Reusing the batteries to provide stationary power benefits the environment and “addresses two concerns: the intermittency of renewable resources and supporting grid stability,” Threlkeld said. Plus, the growth of distributed generation resources like solar, wind and battery storage, opens “a whole new avenue of revenue stream to projects through ancillary sources,” he added.
The data center already has a 74 kilowatt ground-mount solar array and two 2-kW wind turbines that together generate 100 megawatt hours of electricity. That’s enough to power the office building and lighting for the parking lot, or equivalent to the energy needs used by 12 average households.
The batteries can also be used to provide back-up power to the data center for up to four hours if there is a power outage. They can store the power when it’s not needed. The secondary use of the batteries as a pilot project to better understand how energy is redistributed by them at a larger scale. GM is working with partners to both validate and test systems for other commercial and non-commercial uses.
The combination of generating renewable energy and storing it allows the “building to be net zero, meaning that the total amount of energy used by the building is roughly equivalent to, or even less than, the amount of renewable energy generated onsite,” Threskeld explained.
The data center in Milford attained LEED Gold certification, as did GM’s data center in Warren, Michigan, that opened in 2012. Less than 5 percent of the data centers in the U.S. achieve LEED certification, according to the U.S. Green Building Council. Both data centers use in-row cooling to contain heat in a smaller area so less air is moved, which reduced electricity use.
GM also utilizes the cooler climate in Michigan by pumping water outside to let it cool naturally, which allows the cooling system to power down three-quarters of the year. And that saves energy.
The data centers have also found a way to eliminate energy-draining transformers that generate heat to convert power to the appropriate voltages by distributing power at higher voltages. That is something that reduces power loss by 17 percent.
Image credit: General Motors