Catching the wind with electric cars

As more electric cars hit the road, more wind power may be able to hit the grid. Two studies explore how.
Written by Melissa Mahony, Contributor

An electric vehicle doesn’t just consume electricity. Its battery stores power, taken from the grid for use later on the road.  When that power originates at a wind turbine or solar cell, the electric cars avoid burning fossil fuels. Unfortunately, the grid's limited storage capacity can't always accept the full surge of power coming in during windy weather. But if enough electric cars charge up at the right time, their batteries en masse could help welcome more renewable energy to the grid.

Two recent studies explore how hybrid and electric cars could help smooth out the gusts of wind power entering the electric grid and the technologies that could help them do so.

The first study, conducted by the Pacific Northwest National Laboratory (PNNL), looks at the growing wind industry in the Northwest. Renewable energy standards across seven states could add as much as 10 gigawatts of wind energy capacity by 2019. The region’s existing wind industry has already been running into trouble with the grid. During last spring’s snow melt, for instance, the transmission agency asked wind farms to power down at night to make room for the influx of hydropower from the area’s gushing rivers. A lawsuit ensued.

To avoid similar supply clashes, or crashes, in the future, the PNNL study estimated the region would need 2.1 million hybrids and full-electric vehicles to help balance a grid with more wind power. These cars would represent 13 percent of the area’s current light-duty vehicles. The region wouldn’t just need many more cars plugging in, the researchers concluded, but cars that plug in smarter.

Charging up at night when demand is down helps. In addition, the study analyzed two charging systems with which cars would not suck up power at a steady rate. Instead, what they call grid friendly technologies would constantly assess grid conditions so the car could adjust its charging accordingly.

On an island on the other side of the planet, another study has been underway. Denmark’s 227-square-mile Bornholm Island in the Baltic Sea gets about a third of its electricity from renewable energy, most of which is wind power. The EDISON project—a consortium of companies including DONG Energy, IBM and Siemens—examined the interactions between electric car owners and the grid for two years.

The project found that the best charging scenarios would occur when EV owners could stagger their charging times throughout the night or set the charging time for whenever power demand lessens. The owners schedule the charge through their smartphones with apps that also detail the price difference between 'filling up' now or waiting until later.

Greenbiz.com reports:

To make this happen, drivers only had to program their cars, using a smart phone app, to charge when electricity is cheap. Once the car knows when the owner prefers to charge up, EV owners could simply plug them in and walk away. The car's computer then communicated with the grid and started charging when the time is right and other vehicles were not charging.

Earlier this week, the small-scale study demonstrated some of its results at a workshop and in this video. To broaden its understanding of electric vehicles could add flexibility to the grid, the EDISON project will monitor how 2,000 homes in a larger EcoGrid Project.

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Images: Wikipedia Commons

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