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  • [INTRO ♪]

  • Telling people that buying an electric car

  • is a great way to fight climate change is

  • a pretty reliable way to start an argument in some circles.

  • People will say that you still burn fossil fuels

  • with electric carsit just happens

  • at the power plant instead of the engine.

  • And while that's at least partly true,

  • over their lifespans, electric cars don't consume

  • anywhere near the fossil fuels that

  • gas-powered cars doespecially in the United States.

  • With electricity getting cleaner all the time,

  • they're even better than you might expect.

  • There are a few variables to keep in mind though,

  • starting with the cars themselves.

  • In the US as of 2016, the average pure-gasoline

  • passenger car goes about nine kilometers

  • for each liter of gas it burns,

  • or about twenty-two miles per gallon,

  • but that's just an average.

  • Some go four kilometers or so; others go fourteen.

  • But the fuel efficiency hits higher highs,

  • and lower lows, when we start talking about

  • hybrid cars or trucks on the interstate.

  • Plus, the act of manufacturing a car

  • leads to greenhouse gas emissions --

  • whether it's electric or not.

  • So does refining gasoline.

  • But the major complicating factor here is electricity.

  • And where you live determines

  • how clean your electricity really is.

  • Most electricity in the US uses a combination

  • of natural gas, coal, and nuclear fission

  • with a bit of water, wind, solar, oil,

  • and a few others thrown in.

  • But those numbers change from state to state,

  • and depend on things like local natural gas sources

  • or how windy it is today.

  • For example, Alaska has plenty of natural gas

  • and hydroelectric resources, so its power plants

  • create very little waste when generating electricity.

  • That means a full electric vehicle charge

  • using Alaskan electricity creates roughly

  • the same emissions as a gas engine that

  • drives 48 kilometers per liter or 112 mpg.

  • That's roughly five times the national average,

  • and two or three times better

  • than even some of the best hybrids.

  • It's pretty efficient!

  • But at the other extreme are places like Colorado,

  • which, energetically speaking,

  • is one of the dirtiest states. Sorry Colorado.

  • About half of Colorado's electricity is from coal,

  • which produces more emissions

  • than just about any other source.

  • But even there, electric cars

  • still outperform gas cars.

  • A full charge off of Colorado electricity

  • equates to about twenty kilometers per liter (46 mpg) –

  • about double the national average, based on 2016 figures.

  • That's pretty good.

  • Better still, most of the country is closer

  • to Alaska's numbers than Colorado's.

  • It comes down to this:

  • Power plants are just better at making power

  • than car engines are.

  • One reason is that they're simply bigger.

  • Bigger things don't waste as much energy staying hot

  • -- and that makes them more efficient.

  • And the story is similar across most of the world,

  • although again the details change depending on

  • where your electricity comes from.

  • In countries that tend to use more coal,

  • like India or China, electric cars break even

  • with the average gas-powered car in the US

  • although they're still less efficient

  • than the average Indian gas-powered car.

  • But in water-powered Paraguay

  • or geothermal-rich Iceland,

  • gas engines need to get more than

  • 90 kilometers per liter to beat an electric one.

  • So are electric vehicles really more efficient than gas?

  • Yes, they absolutely are

  • unless you have some very dirty electricity.

  • So much for thewell, actually”s.

  • But climate change isn't just one problem;

  • it's a hot mess of many problems at once.

  • And it'll take some pretty radical changes

  • from people all over the world to keep that

  • hot mess from getting even hotter.

  • Thanks for asking.

  • Before you go, you may or may not be aware

  • that I wrote a book!

  • And that bookis out in paperback now.

  • I didn't tell you about it when it was just hardcover,

  • but now you can get it in value discounted,

  • not-as-hard edition!

  • It's a book about a girl who gets famous on the internet,

  • which is something I know a little bit about.

  • And it's also about like, space aliens, some.

  • So if sci-fi mixed with fame destroying people

  • sounds like an interesting story to you,

  • check it out! It's available wherever books are sold.

  • It's called An Absolutely Remarkable Thing.

  • [OUTRO ♪]

[INTRO ♪]

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A2 初級

電動汽車真的更環保嗎? (Are Electric Cars Really More Environmentally Friendly?)

  • 18 3
    林宜悉 發佈於 2021 年 01 月 14 日
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