Electric Cars: Are They Actually Cleaner?

If you've ever read the comments of any article about electric cars, you've probably run into some variant on this argument: "Electric cars aren't green to begin with, since the wall socket they're plugging into likely connects to a fossil fuel power plant."

In this article, we're going to look at some relevant data to see if that's true.

To start with, an electric motor is about 85-90% efficient at turning stored energy into wheel motion. For comparison the average internal combustion engine is around 15-25% efficient, losing most of the energy in gasoline as waste heat.

Therefore, an electric car at this stage consumes between 3 and 6 times less energy per mile driven than a gas car, which in turn incurs less pollution at the power plant. It's worth noting here that combined cycle coal plants are around 60% efficient, a huge improvement over the paltry efficiency of an automotive engine. This is because of machinery which uses the waste heat to generate additional power, but also because the larger you make an internal combustion engine the more efficient it can be.

Nationally just 37% of electricity comes from coal, not the 100% frequently assumed by opponents of electric vehicles or anywhere close to it. And 30% of the grid is ghg emissions free stuff like nuclear and renewables. In my state nearly half the energy comes from hydroelectric. Charging from that mix is substantially better than driving a car which gets 100% of its power from fossil fuels.

So, what about losses? Typical charging loss for lithium ion batteries is around 1%. Average line loss for power transmission is 7%. If you take the efficiency of generating power in your own state and then sending it over powerlines to your home, also in your own state and compare that to the process of drilling for oil at sea, shipping it to shore in bunker oil burning tanker vessels, refining it onshore, then burning some of the resulting gasoline to truck it to gas stations nationwide it becomes pretty clear which method of getting 'fuel' into your car is more efficient and environmentally friendly.

Have a look at this MIT study confirming that even on today’s grid and with full lifetime manufacturing and disposal emissions taken into consideration EVs are still about twice as clean to create, operate and dispose of than gas vehicles.

If at this point you're thinking "But wait a minute, I've seen several credible articles claiming electric cars are actually dirtier than, or just as dirty as, gas powered cars." Yes you did, all of them written by Bjorn Lomborg or based on his work. Here's an example. Here's another. Here's another. Mr. Lomborg really gets around, you see.

Bjorn's day job is to propagate misinformation about alternative energy and climate change, on the payroll of industrialists opposed to cap and trade. An industry shill, in other words. If you look around you can find numerous articles picking apart his math and showing where he has fudged his figures in order to arrive at the conclusion his paymasters wanted.

This is ironically exactly what climate change deniers accuse environmentalists of doing. Often it backfires though. Sometimes scientists are paid by the likes of the Koch brothers to recreate the experiments which led to the conclusion that human pollution is exacerbating climate change, but the scientist isn't corrupt, and produces results confirming that indeed that's what is occurring.

You might then ask, "But why electric? I've heard lots of good things about hydrogen fuel cell cars, they seem very promising." I will cover that, and a variety of other possible alternatives to electrics, in a future article.