MAE Professor Rajit Gadh was quoted in the BeFutureReady article “V2G: Are We There Yet?”
Excerpted from article:
There are already a few vehicles on the road that are capable of bi-directional electricity flow. That is, instead of sending power from the battery to the drive train, they can send electrons to the grid. “But, for the majority of EVs, that capability has not been made available inside the vehicle by the manufacturer,” explains Rajit Gadh, a professor at the UCLA Henry Samueli School of Engineering and Applied Science and founding director of the UCLA Smart Grid Energy Research Center. Gadh says making vehicles V2G-ready is “not a complex matter.”
What prevents manufacturers from making the change? Gadh thinks part of the delay is the potential wear and tear on the batteries themselves.
There are only a certain number of charge-discharge cycles in a battery’s life span, he says. “If you do what is called a deep charge and discharge for the grid, you are eventually going to wear out the battery, even if you don’t drive the vehicle at all.” Often, he adds, car manufacturers warranty vehicles for a certain number of miles, and V2G capability has the potential to leave those manufacturers stuck with a guarantee that comes due before these miles get driven because the battery was used up for an unintended purpose.
Gadh sees a potential solution. “We’re getting more and more data from research around the world showing that if you do a shallow depth of discharge – say 10 percent – you’re not wearing out the battery as much as if you’re doing an 80 percent depth of discharge,” he says. Such findings are preliminary, and Gadh says more study must be done.
Meanwhile, how do we compensate owners for the right to tap their batteries? “It’s a matter of economics,” Gadh notes. “We still must fine-tune the technology – e.g., deep versus shallow discharge options – and market incentives to make V2G profitable for all”.