Electric vehicles accounted for a tiny fraction of the annual 10-million new vehicle sales in the United States in 2009, and an even smaller proportion of the country's overall vehicle fleet, which experts at the Earth Policy Institute figure is about 246 million vehicles. But with the number of EVs expected to grow, what happens when there are more of them on the road?
If the market grows to, say, five or even ten percent of new vehicle sales, what other ramifications will that have? Some would say that our air will be cleaner and our dependence on oil will drop, but there are other questions to ask. For instance, how will roads be funded and can our existing electricity grid handle all these EVs plugging in?

These topics are up for debate and investigation.

How Do We Fund The Roads?

Roads and EVs might not mix well. Currently, states and the federal government fund public road construction and maintenance using taxes assessed on gasoline and diesel fuels. There isn't a way to tax EV drivers for their "fuel," but they'll be using the same roads. Shouldn't they have to pay for the use of the road?

Imagine what would happen if a significant percentage of road taxes simply vanished? Road commissions faced with declining tax revenue -- but no equivalent drop in road usage -- would still need to provide the maintenance and improvements to keeps roads useable.

Washington state legislators are already grappling with the issue. A bill (SB 6377) was introduced early in 2010 and comes up for a second reading early in 2011. Details of the bill include levying a $100 road tax on top of the annual vehicle registration fee for owners of EVs.

Other states are considering adding a road tax to electricity used to recharge EVs. This would be accomplished in cooperation with utilities that require a separate electricity meter and circuit for EV recharging. Other voices in government and the EV community are investigating an annual vehicle mileage tax that assesses a tax based on the number of miles a vehicle travels.

At this point, nobody knows what road tax solution will emerge. The good news for early EV adopters is that between now and whenever decisions are implemented, you're getting a free ride.

How Do We Power Electric Vehicles?

How do we power the electric cars of the future? The question isn't easily answered because there are hundreds of utility companies across the U.S. Local and regional grids vary widely in their condition. However, to ferret out some kind of answer regarding whether current electrical grids can handle an uptick EV sales, Translogic talked with a representative of DTE Energy, Southeastern Michigan's electricity and natural gas utility.

"Our system is fully capable of handling the expected ramp of up EVs," said Ana Medina, DTE Energy Marketing Program Manager. "The additional load from a few EVs plugging into the grid in the same neighborhood can be handled with the built-in capacity we have." According to Chevrolet, a Chevy Volt driven 15,000 miles annually consumes about the same electricity (approximately 2,500 kW) as a standard household refrigerator.

But what happens if the number is more than "a few EVs?"

Medina went on to explain that they'll watch how demand grows. DTE can track EV customers because the utility recommends EV buyers put their 240-volt EV chargers on a separate meter to benefit from special pricing plans. DTE will add capacity as a normal course of business on an as-needed basis when and where EVs become more popular.

"We expect to see groupings of EV owners at first," said Medina, "and with the limited number of EVs coming to market, we'll be able to enhance our grid as necessary."

Let's hope other utilities take DTE's practical approach.