What’s the best fuel for your car?

譯者: 耀祖 施 審譯者: Helen Chang

Historically, most cars have run on gasoline,

歷史上大多車子以汽油作燃料，

but that doesn’t have to be the case in the future:

但未來可不一定也是這樣：

other liquid fuels and electricity can also power cars.

其他液態燃料和電 也能作為車子的動能。

So what are the differences between these options?

那麼這些燃料有哪裡不同？

And which one’s best?

哪一種又是最好的呢？

Gasoline is refined from crude oil,

汽油是由原油所精煉，

a fossil fuel extracted from deep underground.

是從地底深處所萃取的石化燃料。

The energy in gasoline comes from a class of molecules called hydrocarbons.

汽油的能量來自碳氫化合物。

There are hundreds of different hydrocarbons in crude oil,

原油中有上百種不同的碳氫化合物，

and different ones are used to make gasoline and diesel—

製作汽油和柴油所用的就不同，

which is why you can't use them interchangeably.

這就是為什麼它們不能互換使用。

Fuels derived from crude oil are extremely energy dense,

原油衍生的燃料能量極度密集，

bringing a lot of bang for your buck.

能夠花少錢得大效果。

Unfortunately, they have many drawbacks.

不幸的，這些燃料有很多缺點。

Oil spills cause environmental damage and cost billions of dollars to clean up.

漏油傷害環境，清潔成本高達數十億。

Air pollution from burning fossil fuels like these

燃燒此等石化燃料造成的空氣汙染

kills 4.5 million people each year.

每年導致 450 萬人死亡。

And transportation accounts for 16% of global greenhouse gas emissions,

交通所排放 就佔全球溫室氣體的 16% ，

almost half of which comes from passenger cars burning fossil fuels.

近乎一半來自客車燃燒石化燃料。

These emissions warm the planet and make weather more extreme.

這些排放使地球暖化 並造成更加極端的氣候

In the U.S. alone, storms caused by climate change

光是在美國，氣候變遷所帶來的風暴

caused $500 billion of damage in the last five years.

在過去五年就造成 5000 億美元損失。

So while gas is efficient,

因此，即便汽油使用上很有效率，

something so destructive can't be the best fuel.

但如此具破壞性不會是最好的燃料。

The most common alternative is electricity.

最常見的替代品是電力。

Electric cars use a battery pack and electric motor

電動車使用電池組和電動馬達

instead of the internal combustion engine found in gas-powered cars,

而非汽油車用的內燃機，

and must be charged at charging stations.

且只能在充電站充電。

With the right power infrastructure, they can be as efficient as gas-powered cars.

只要有適當充電建設， 電動車也可以跟燃油車一樣有效率。

If powered by electricity generated without fossil fuels,

若是不靠石化燃料產生的電力所驅動，

they can avoid greenhouse gas emissions entirely.

則可以完全免除溫室氣體的排放。

They’re more expensive than gas-powered cars,

電動車比汽油車更貴，

but the cost difference has been shrinking rapidly since 2010.

但 2010 以來 兩者的成本差異已迅速縮小。

The other alternatives to gasoline are other liquid fuels.

汽油的其他替代品是其他液態燃料。

Many of these can be shipped and stored using the same infrastructure as gasoline,

許多液態燃料可透過汽油用基礎設施 運送並且儲存，

and used in the same cars.

並用於相同的車子。

They can also be carbon-neutral if they’re made using carbon dioxide

這些也可能是碳中和的燃料，

只要這些燃料是用 大氣中的二氧化碳製造的，

from the atmosphere—

meaning when we burn them, we release that same carbon dioxide back into the air,

也就是當這些燃料燃燒時， 便將原本的二氧化碳釋放回空氣中，

and don't add to overall emissions.

整體排放不會增加。

One approach to carbon-neutral fuel is to capture carbon dioxide

捕捉大氣中的二氧化碳，將其中的碳

from the atmosphere and combine its carbon with the hydrogen in water.

與水中的氫結合是碳中和燃料的途徑。

This creates hydrocarbons, the source of energy in fossil fuels—

這創造出碳氫化合物， 即石化燃料的能量來源，

but without any emissions if the fuels are made using clean electricity.

只要用乾淨的電力產生燃料 就不會有任何排放。

These fuels take up more space

相較於汽油等量的能源，

than an energetically equivalent amount of gasoline—

這些燃料占用更多空間，

an obstacle to using them in cars.

是用於車上的一個障礙。

Another approach is to make carbon-neutral fuels from plants,

另一個途徑是以植物製造碳中和燃料，

which sequester carbon from the air through photosynthesis.

透過光合作用隔離空氣中的碳。

But growing the plants also has to be carbon neutral—

但栽種植物也必須以碳中和的方式，

which rules out many crops that require fertilizer,

這排除了許多需要使用 化學肥料的農作物，

a big contributor to greenhouse gas emissions.

會排放大量溫室氣體化肥的農作物。

So the next generation of these fuels must be made from either plant waste

所以這些下個世代的燃料 一定是以植物廢棄

or plants that don't require fertilizer to grow.

或不需化肥栽種的植物來製作。

Biofuels can be about as efficient as gasoline, though not all are.

生化燃料可以跟汽油一樣有效率， 雖然不是所有都是。

For a fuel to be the best option, people have to be able to afford it.

若要成為最好的燃料選項 一定要是人們可負擔的。

Unfortunately, the high upfront costs of implementing new technologies

很不幸，採用新技術高額的前置成本，

and heavy subsidies for the producers of fossil fuels,

以及石化燃料生產者的高額補貼，

mean that almost every green technology

表示幾乎每項綠色科技

is more expensive than its fossil-fuel-based cousin.

都比石化類的相似科技還要更貴。

This cost difference is known as a green premium.

這種成本上的差異也就是綠色溢價。

Governments have already started subsidizing electric vehicles

政府已開始提供電動車補貼

to help make up the difference.

幫助彌補這種差異。

In some places, depending on the costs of electricity and gas,

在某些地方，根據電力和汽油的成本

electric cars can already be cheaper overall,

使用電動車整體上會更加便宜，

despite the higher cost of the car.

即便電動車本身要價不斐。

The other alternatives are trickier, for now—

目前，其他替代品使用上更困難，

zero-carbon liquid fuels can be double the price of gasoline or more.

零碳液態燃料要價是汽油兩倍以上。

Innovators are doing everything they can to bring green premiums down,

創新者盡其所能使綠色溢價下降，

because in the end, the best fuel will be both affordable for consumers

因為最終，最好的燃料 必須是消費者可負擔

and sustainable for our planet.

又可以在我們的星球上永續使用的。