I talked about vehicle-to-grid (V2G) technology, and turning batteries into generators, with Dr. Michael Kintner-Meyer, an electrical power systems integration engineer with the Pacific Northwest National Laboratory. He raised a question in my mind that, in the ensuing months, hasn’t been fully resolved for me: will we earn enough by selling our electric vehicles’ extra power back to the utility to cover the cost of replacing that battery prematurely?
Back in early September, I talked about vehicle-to-grid (V2G) technology, and turning batteries into generators, with Dr. Michael Kintner-Meyer, an electrical power systems integration engineer with the Pacific Northwest National Laboratory.
He raised a question in my mind that, in the ensuing months, hasn’t been fully resolved for me: will we earn enough by selling our electric vehicles’ extra power back to the utility to cover the cost of replacing that battery prematurely? Or is there a better way to go about the whole electric vehicle/balancing load/distributed generation roadmap?
The Green Car Congress (GCC) recently published research from the Carnegie Mellon Electricity Industry Center which takes steps to chip away at the question. Researchers there concluded that a plug-in hybrid electric vehicle (PHEV) pack made up of lithium iron phosphate cells “would incur little capacity loss from combining vehicle-to-grid activities with regular driving.” In fact, the GCC went on to note, “Statistical analyses indicated that rapid battery cycling incurred when driving degraded the cells more than slower, vehicle-to-grid galvanostatic cycling.”
“However,” the GCC article went on to note—and this is a big “however” in the consumer equation, in my opinion—“in a companion paper assessing the economics of V2G for consumers, [the study’s authors] also concluded that the maximum annual profit for a PHEV owner to engage in V2G (~$10-$120) would likely prove insufficient to encourage use of the battery pack for grid electricity storage and later off-vehicle use.”
This kind of minimal expected profit isn’t exactly the carrot needed to entice consumers to share their battery power. Add to that another question: will using an electric car’s approximately $8,000 battery for V2G void its warranty? How’s this being addressed?
And then, there’s the issue of how green electric vehicles really will be, in the general scheme of things. Houston mayor Bill White, a long-time advocate of making the grid more reliable, was in the news over the weekend, pointing out the hypocrisy of a blanket assumption that electric vehicles will green the grid. While he supports electric vehicles, White told the Dallas Morning News: “If they say there’s no emissions, they just don’t know where the power comes from.”
In states using primarily coal-fired electricity, the change the electric vehicle brings to the equation is a lot more complicated, with the end solution to the carbon-use equation a bit more muted. While electric vehicles cut carbon dioxide emissions considerably when compared with cars fueled by gasoline, in carbon-fired states like Texas, which gets about 37 percent of its electricity from coal, they’ll still be creating nitrogen oxides in their fueling.
And if that’s not enough to get the questions spinning, consider the following: According to the same Dallas Morning News article, while charging an electric vehicle in the state of Texas would create about half as much carbon dioxide as a gasoline vehicle, data from the Environmental Agency on Texas power plant emissions in 2008 indicate an electric vehicle “would be responsible for slightly more nitrogen oxides than a brand-new gasoline car.”
Just to muddy the playing field a bit more, let’s consider the type of energy used to manufacture the steel, the plastic, the polycarbonates, and even the battery pack for these new electric vehicles. Yes, it’s on par with the type of energy used to manufacture a gasoline-fired car. But that means there are no carbon savings there, either.
And then there’s the massive increase in demand for lithium ion batteries, and the issue of their eventual disposal. Do we have either of these issues in hand yet?
As with other areas in the emerging smart grid, the technology itself is there, or nearly there. But is the infrastructure, the electricity superhighway we’re creating here, ready to deal with all of the technology being put on the on-ramps? Are we really ready for prime time yet?
I look forward to discussing this and other issues with all the players in the emerging intelligent utility. If you have a story to tell me, or thoughts you’d like to share, please contact me by e-mail at email@example.com  or by telephone at 720-331-3555.