Using retired electric vehicle (EV) batteries in smaller, localized power grids could be a “game-changer” for microgrid owners, say the proponents of an innovative plan to reduce grid costs and emissions.

Microgrid provider Instant On is working with NICE America Research—an incubator for China Energy that researches clean energy and other ways to move to a low-carbon economy—to put second-life EV batteries to the test with three of Instant On’s pilot projects in multi-family housing, indoor cannabis grow facilities, and a gas station microgrid, reports Microgrid Knowledge.

EV batteries retain 80% capacity even after they are taken out of service, said A.J. Perkins, president of Instant On. Although they are no longer useful for powering vehicles, they can still have effective applications in stationary storage applications at only 30% to 70% the cost of new batteries. 

But factors like climate or driving habits during a battery’s formative years will have an impact on second-life performance, leading to varying levels of battery performance. Because batteries are linked in packs to power EVs, one low-capacity battery can limit the performance of the entire array.

Although performance limitations can be weeded out by cycling and grading batteries to predetermine capacity, “grading them and estimating their state of health involves cost. You spend capital and labour to do that,” said Surinder Singh, director of engineering at NICE America Research.

The company has developed a less expensive grading system to keep second-life battery costs low.

“The key is how we can use the battery packs without disassembly or reassembly. We are spending minimal resources to get a health measurement,” Singh said.

The two companies plan to test the researchers’ new technology with Instant On’s customers.

“It is ready to go. We need to manufacture it at scale; it’s ready for commercialization. But now we need to develop the supply chain and manufacturing,” Singh said.

One priority is using second life batteries in microgrids on both sides of the meter, to help those who are subject to power outages, Singh said.

“This application has the highest potential impact to the grid and utilities,” said Perkins, adding that if a significant percentage of solar arrays became microgrids or nanogrids, it would be “a major game changer.”