Dear Car Talk:
I keep wondering about electric cars and emissions. Unless you charge from a home with solar panels, you have to charge your car from the electric grid, which mostly uses natural gas. That would cause pollution. Everyone seems to think that if you drive an electric car, you have no pollution footprint, but that is not the case.
Perhaps hydrogen fuel cells might have a better pollution footprint since I believe the emissions would be nothing but water vapor. What do you think is the best way to proceed with this long-term decision? — Roger
You’re right that there’s very little free energy, Roger, unless you always drive downhill. But here’s why electric cars create less pollution than gasoline-powered cars. With a gas-powered car, you have tens of millions of engines, and tens of millions of catalytic converters, all in different states of age, maintenance and disrepair.
While most states have annual or biannual emissions inspections, it’s a lot harder to police tens of millions of individual cars — where a guy can slip a mechanic a $50 to help him cheat the emissions test — than it is to police a few thousand power plants.
Fewer and fewer power plants run on coal these days, which has the worst pollution footprint of the fossil fuels. There are lots of plants that run on natural gas, which, while not as clean as wind and solar, is cleaner than oil and gasoline.
And, increasingly, utilities are adding solar and wind power to their generation systems. So, over time, I would expect the amount of pollution created by our electric grid to drop and the argument for electric vehicles to get stronger.
Add to that: Electric cars remove pollution from places where traffic is densest and air pollution is the worst, like in crowded cities. So electric cars should make a big dent in air quality and public health over time.
Hydrogen is a possibility. Hydrogen fuel cells work by combining hydrogen with oxygen to create water, a chemical reaction that produces electricity. That electricity is created onboard the vehicle, and then used to power an electric motor. And, as you say, Roger, the only by-product is water.
The biggest advantage to hydrogen, at the moment, is that it can provide a longer range than some of today’s batteries and allows you to refuel in about the same time as it takes to fill a traditional gas tank. But you have to make, transport, store and deliver the hydrogen. And unless you do all that with renewable energy, hydrogen power creates some pollution, too.
So what’s the best way to proceed long term? Well, if you live in a place where solar power works well, you can reduce your pollution footprint by getting an electric car and charging it at home using your own solar panels.
And in the bigger picture, the best thing we can do to reduce automobile pollution and improve public health is to move toward electric or fuel cell cars and work to increase the percentage of renewable, non-polluting generation in our electric grids.
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