Historically, most cars have run on gasoline, but that doesn’t have to be the case in the future: other liquid fuels and electricity can also power cars. So what are the differences between these options? And which one’s best?
歷史上大多車子以汽油作燃料, 但未來可不一定也是這樣: 其他液態燃料和電 也能作為車子的動能。 那麼這些燃料有哪裡不同? 哪一種又是最好的呢?
Gasoline is refined from crude oil, a fossil fuel extracted from deep underground. The energy in gasoline comes from a class of molecules called hydrocarbons. There are hundreds of different hydrocarbons in crude oil, and different ones are used to make gasoline and diesel— which is why you can't use them interchangeably.
汽油是由原油所精煉, 是從地底深處所萃取的石化燃料。 汽油的能量來自碳氫化合物。 原油中有上百種不同的碳氫化合物, 製作汽油和柴油所用的就不同, 這就是為什麼它們不能互換使用。
Fuels derived from crude oil are extremely energy dense, bringing a lot of bang for your buck. Unfortunately, they have many drawbacks. Oil spills cause environmental damage and cost billions of dollars to clean up. Air pollution from burning fossil fuels like these kills 4.5 million people each year. And transportation accounts for 16% of global greenhouse gas emissions, almost half of which comes from passenger cars burning fossil fuels. These emissions warm the planet and make weather more extreme. In the U.S. alone, storms caused by climate change caused $500 billion of damage in the last five years.
原油衍生的燃料能量極度密集, 能夠花少錢得大效果。 不幸的,這些燃料有很多缺點。 漏油傷害環境,清潔成本高達數十億。 燃燒此等石化燃料造成的空氣汙染 每年導致 450 萬人死亡。 交通所排放 就佔全球溫室氣體的 16% , 近乎一半來自客車燃燒石化燃料。 這些排放使地球暖化 並造成更加極端的氣候 光是在美國,氣候變遷所帶來的風暴 在過去五年就造成 5000 億美元損失。
So while gas is efficient, something so destructive can't be the best fuel. The most common alternative is electricity. Electric cars use a battery pack and electric motor instead of the internal combustion engine found in gas-powered cars, and must be charged at charging stations. With the right power infrastructure, they can be as efficient as gas-powered cars. If powered by electricity generated without fossil fuels, they can avoid greenhouse gas emissions entirely. They’re more expensive than gas-powered cars, but the cost difference has been shrinking rapidly since 2010.
因此,即便汽油使用上很有效率, 但如此具破壞性不會是最好的燃料。 最常見的替代品是電力。 電動車使用電池組和電動馬達 而非汽油車用的內燃機, 且只能在充電站充電。 只要有適當充電建設, 電動車也可以跟燃油車一樣有效率。 若是不靠石化燃料產生的電力所驅動, 則可以完全免除溫室氣體的排放。 電動車比汽油車更貴, 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. Many of these can be shipped and stored using the same infrastructure as gasoline, and used in the same cars. They can also be carbon-neutral if they’re made using carbon dioxide from the atmosphere— meaning when we burn them, we release that same carbon dioxide back into the air, and don't add to overall emissions.
汽油的其他替代品是其他液態燃料。 許多液態燃料可透過汽油用基礎設施 運送並且儲存, 並用於相同的車子。 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, 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, 整體排放不會增加。
One approach to carbon-neutral fuel is to capture carbon dioxide from the atmosphere and combine its carbon with the hydrogen in water. This creates hydrocarbons, the source of energy in fossil fuels— but without any emissions if the fuels are made using clean electricity. These fuels take up more space than an energetically equivalent amount of gasoline— an obstacle to using them in cars.
捕捉大氣中的二氧化碳,將其中的碳 與水中的氫結合是碳中和燃料的途徑。 這創造出碳氫化合物, 即石化燃料的能量來源, 只要用乾淨的電力產生燃料 就不會有任何排放。 相較於汽油等量的能源, 這些燃料占用更多空間, 是用於車上的一個障礙。
Another approach is to make carbon-neutral fuels from plants, which sequester carbon from the air through photosynthesis. But growing the plants also has to be carbon neutral— which rules out many crops that require fertilizer, a big contributor to greenhouse gas emissions. So the next generation of these fuels must be made from either plant waste or plants that don't require fertilizer to grow. Biofuels can be about as efficient as gasoline, though not all are.
另一個途徑是以植物製造碳中和燃料, 透過光合作用隔離空氣中的碳。 但栽種植物也必須以碳中和的方式, 這排除了許多需要使用 化學肥料的農作物, 會排放大量溫室氣體化肥的農作物。 所以這些下個世代的燃料 一定是以植物廢棄 或不需化肥栽種的植物來製作。 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. Unfortunately, the high upfront costs of implementing new technologies and heavy subsidies for the producers of fossil fuels, mean that almost every green technology is more expensive than its fossil-fuel-based cousin. This cost difference is known as a green premium.
若要成為最好的燃料選項 一定要是人們可負擔的。 很不幸,採用新技術高額的前置成本, 以及石化燃料生產者的高額補貼, 表示幾乎每項綠色科技 都比石化類的相似科技還要更貴。 這種成本上的差異也就是綠色溢價。
Governments have already started subsidizing electric vehicles to help make up the difference. In some places, depending on the costs of electricity and gas, electric cars can already be cheaper overall, despite the higher cost of the car. The other alternatives are trickier, for now— zero-carbon liquid fuels can be double the price of gasoline or more. Innovators are doing everything they can to bring green premiums down, because in the end, the best fuel will be both affordable for consumers and sustainable for our planet.
政府已開始提供電動車補貼 幫助彌補這種差異。 在某些地方,根據電力和汽油的成本 使用電動車整體上會更加便宜, 即便電動車本身要價不斐。 目前,其他替代品使用上更困難, 零碳液態燃料要價是汽油兩倍以上。 創新者盡其所能使綠色溢價下降, 因為最終,最好的燃料 必須是消費者可負擔 又可以在我們的星球上永續使用的。