How green is the Volt really?

As GM finally unveils its next-gen game-changer, the question on everyone's mind is whether getting your car's power from the grid is better for the environment than getting it from gasoline. The short answer is yes.

Even if you never plug it in, this thing is going to be a green car. Once the Volt uses up all of its electric charge, an on-board generator kicks on to recharge its batteries. From that moment on, the Volt will get something like 50 miles per gallon, better than any Chevy on the road right now, and also probably better than the Prius. This is possible because the generator only has to operate at one speed, so it can be tuned for efficiency rather than versatility.

An important question is whether grid electricity is greener than gasoline power.

Several studies have been done on the probable effects of extended-range EVs and other plug-in vehicles, and they have all found that the technology decreases emission of greenhouse gasses significantly.

The NRDC's study found that widespread adoption of plug-in technology would reduce greenhouse gasses by about 450 million metric tons per year, a huge number. It would be the equivalent of taking 80 million cars off the road completely and it would reduce our oil consumption by almost four million barrels per day (about 20x more than we'd get from drilling offshore, by the way.)

Additionally, plug-in vehicles are the only cars that actually get greener as time goes on. As we phase out old, inefficient coal-fired power plants, and replace them with renewable technology like geothermal, wind and solar, plug-in vehicles see corresponding boosts in their carbon efficiency.

Plug-ins will produce more of some emissions however. Gas exhaust doesn't have the same emissions as coal-smoke, so the emissions profile for the car will shift. Instead of unburned hydrocarbons and NOx being the problem, these vehicles will be responsible for more sulfur and mercury emissions. Which is worse is, frankly, a toss-up.

In the end, the Volt will definitely be the greenest car on the road in 2011. But this ecogeek would never say that it's The Solution. It's a big step, but a great deal more work needs to be done before we have a truly sustainable transportation system.

If you missed them and want some eye candy, check out those gorgeous hi-res shots of the Volt that GM released earlier today.