Electric vehicles are definitely eye candy, as our very own Andrew Nusca found out when he took the Chevrolet Volt out for a spin. Deciding to purchase an electric vehicle might seem cool, but charging it at home might make your neighbors’ light go out.
Today in San Francisco at GreenTech Media’s The Networked EV: Smart Grids and Electric Vehicles, PG&E smart grid director Kevin Dasso spoke about the impact electric vehicles might have on neighborhoods bearing the extra load of early EV adoption.
First, Dasso explained how the power grid operates. Basically, you have a power station that sends electricity to neighborhoods by way of transformers that deliver power to a number of homes. Charging an EV to the grid adds about two more houses.
If you overload the grid, you’ll end up with a bunch of angry neighbors who don’t have power because you wanted to charge your car.
In his talk, Dasso also anticipated what would happen if a few neighbors went out and bought an EV today.
“Look out on the poles, the device looks like a garbage can on top of the pole. That’s the distribution transformer,” Dasso said.
The power grid in Berkeley was built to handle the homes sucking power from it — not for plugging in EVs. Dasso described the current power grid of a hypothetical Berkeley neighborhood that has five homes plugged into one transformer.
When the first EV shows up in that neighborhood, it will be the equivalent of having seven homes connected to that one transformer. The utility might have to do an upgrade to the neighborhood to deal with the clustering effect.
It’s human behavior to want an EV if your neighbors have one, Dasso said, especially if you were thinking of getting an EV before seeing the battery-powered car roll into the hood. So if two neighbors get an EV, then that’s like having nine homes getting feed from one transformer.
The effect is expected to be very localized. Essentially, you’re adding an extra subdivision to the grid when a lot of people in one neighborhood use EVs.