Lab report: Managing intermittent wind energy with EVs

1

Integrating intermittent renewable energy sources like wind into the electric grid has been one of the big challenges facing the smart grid initiative. Now, scientists at DOE's Pacific Northwest National Laboratory (PNNL) say they have what could be a workaround: plug-in EVs.

"Electric vehicles, coupled with grid-friendly charging, offers a great opportunity, right now, to help electric companies integrate additional wind power into our electric system," said Michael Kintner-Meyer, a PNNL staff scientist and co-author of the report Using Electric Vehicles to Meet Balancing Requirements Associated with Wind Power.

While growing in popularity, wind power is notoriously unpredictable – it's not always there when you need it – and on windy days, grid operators struggle with ways to use excess energy or store it. And grid-scale storage is at this point pretty limited in the U.S.

The PNNL researchers calculated that 2.1 million vehicles (about 13% of the total light-duty vehicles in the Northwest) would be needed to "provide the on-again, off-again balancing requirements for integrating 10 Gigawatts of additional wind technology in the region." The number of plug-in EVs on the road now doesn't come close to that number, but is expected to grow as the major car makers are pumping out vehicles like the Nissan Leaf and Chevy Volt.

The researchers also estimated the ratio of public-to-residential charging stations that would be required to take on the variability of wind power. They determined not that many non-residential charging stations would be needed if Grid Friendlyâ„¢ charging technology is used. The technology is sensitive to grid conditions and can vary battery charging rates. Intermittent power from wind farms could be absorbed by starting and stopping EV charging cycles.

"We don't need to wait for vehicle-to-grid, or V2G services, which would require that the electricity would be released back into the grid," Kintner-Meyer said. "We could perform grid-friendly charging now that would provide valuable services to the grid for integrating wind energy."

Adoption of PNNL's approach would mean fewer power plants would need to be built and costs associated with electrifying the transportation system and integrating wind energy could potentially be reduced. Other benefits, he said, would be a reduction of our dependence on imported oil and fewer vehicle emissions.

1

Photo courtesy of Pacific Northwest National Laboratory

More on this topic ...

Plugging in: EPRI issues technical guide on utility role in EV integration

More EVs on the road = more headaches for utilities?