Electric Cars Are Coming, But Can the Grid Even Handle Them?

What will happen when we all plug in our electric cars at the same time?

Have you noticed that plug-in electric vehicles are slowly trickling into the mainstream? If you haven't, you certainly will soon—major automakers like Nissan, Chevrolet, and Toyota all have plug-in electric or hybrid electric offerings set to roll off production lines in the next few years. But there's a catch: As it stands, the electrical grid can't handle the onslaught of electric vehicles that will all start charging at, say, 7 p.m. every evening when commuters get home from work. If everyone in your city or town started driving (and subsequently charging) EVs today, the grid would probably fail. So what can be done?

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As I explained in a previous column, some automakers with EVs in the pipeline are already working on the issue. Ford, for example, recently joined up with Microsoft Hohm for an in-vehicle charging system in the 2011 electric Ford Focus. The system will allow drivers to schedule vehicle charging during off-peak hours, or times when the grid has capacity to spare.

Microsoft and Ford aren't the only companies working on EV charging software. Google is also working on a platform that will use something called a vehicle dispatch algorithm to smooth out the electricity load on the grid. And the U.S. Department of Energy's Pacific Northwest National Laboratory is developing a Smart Charger Controller to automatically juice up vehicles when electricity is cheapest and the demand for power is lowest.

Further down the line, we'll see two-way EV-to-grid communications networks—charge points that can both feed electricity to vehicles and send power from EV batteries back to the grid during times of peak demand. But that technology is still in the experimental stages; one-way grid-to-vehicle connections will almost certainly become prevalent in the short term.

Utilities are also toughening up the electrical grid in anticipation of EVs, which will dramatically increase power consumption in most homes. A study from the Electric Power Research Institute estimates that the upcoming Chevy Volt will increase the energy consumption of the average U.S. home by 13 percent, while the all-electric Nissan Leaf will hike up energy use by 19 percent (they'll both save you a lot on gas, though).

SoCal Edison, one of the most well-prepared utilities in the United States, is surveying its customers to find out which ones plan on buying EVs early. The zip codes with the most early adopters will probably receive wiring and circuitry that can handle excess pressure on the grid. The utility is still trying to figure out how to incentivize drivers to charge during off-peak hours.

Less prepared utilities also have the option of turning to companies like IBM, which offers a readiness assessment service that identifies smart grid weak spots. Even IBM can't help with everything, however—only time will tell if the majority of drivers opt to update their garages for EV charging or juice up vehicles at public charge spots. It's the kind of thing that's hard to predict in advance—and it's why utilities, automakers, and electronics manufacturers need to have all their bases covered when preparing the EV infrastructure.