What if we all got electric cars?

We're not ready for that.

EnerNex consultant Doug Houseman posed that question today at a smart grid conference in Silicon Valley. The answer? We're a long way from being ready.

Right now there are a few thousand electric cars, Houseman said, but with the Nissan Leaf -- which has a waiting list of 130,000 -- the Chevy Volt and other new models coming, we could have several hundred thousand electric cars and hybrids by this time next year.

So what happens then? Here are Houseman's predictions.

- A stop for fuel will go from about six minutes for gas to 30 minutes for a partial charge -- maybe 15 minutes if you are able to swap your battery. A charge with a "garden variety charger" will take about eight hours.

- A 400-plus-pound battery is not easy to change, and not just because it's heavy. The Chevy Volt's battery is wedged under the car's passenger compartment, which it protects from getting crushed, but that also makes it a structural part of the car.

- Most firefighters don't have equipment to fight electrical fires. They're fought with chemicals and not water, so you don't create new conductive paths for the electricity. (However, by the time firefighters get to a car burning on the side of the highway, plastic and upholstery will probably also be burning and it will be a regular fire.)

- Crash test methods will have to change. Water is used in the gas tank now during crash tests, to see where it spills when the car crashes and what the splash path is. But what does it mean during a crash when the battery is penetrated? Before you crash-test an electric car, should you charge it?

- Most houses are not designed for electric cars. Nissan (wisely) plans to send an electrician to your house as part of the purchase price of your car to make sure you have the right fuses and circuit breakers so you can plug it in and charge it.

- Standards are needed for the power grid so cars can negotiate with the utility and with each other on when they can draw power. And what if there are too many cars in one place? Average peak household demand in Kilowatt-hours for an electric car is likely to be far higher than the average demand for the city it's in.

- Car batteries have to be recycled. Also, most of the lithium used for car batteries comes from Chile and other South American countries. These are friendly countries that trade with the U.S., but could the U.S. end up depending on a lithium cartel?

- Electric cars are still expensive (although that will also dampen their popularity). If a Nissan Versa is $10,000 and a Nissan Leaf with a rebate is $30,000, what would that extra $20,000 buy you? Even if gas is $5 a gallon, you could buy 4,000 gallons of gas. At 30 miles per gallon, you could drive 120,000 miles.

So how much are you able to pay, right now, to be greener?

This post was originally published on Smartplanet.com