How much land does it take to power the world?

譯者: Wei-Yu Shih 審譯者: Amanda Zhu

No matter how we make electricity, it takes up space.

不管用什麼方法發電， 都會佔用空間。

Electricity from coal requires mines, and plants to burn it

燃煤發電需要礦場

以及將熱能轉換成電力的火力發電廠。

and convert the heat into electricity.

Nuclear power takes uranium mines, facilities to refine the uranium,

核能需要鈾的礦場、提煉鈾的設施、

a reactor, and a place to store the spent fuel safely.

反應爐以及安全存放核廢料的地方。

Renewable energy needs wind turbines or solar panels.

再生能源則需要風力發電機 或是太陽能版。

How much space depends on the power source.

需要的空間則取決於能源的種類。

Say you wanted to power a 10-watt light bulb with fossil fuels like coal.

假設你想使用煤炭之類的化石燃料 來供電給一顆 10 瓦的燈泡，

Fossil fuels can produce up to 2,000 watts per square meter,

因為以化石燃料發電所用的每平方公尺

最多可以產生 2000 瓦，

so it would only take a credit card-sized chunk of land to power the light bulb.

所以點亮這顆燈泡 只需要一塊信用卡大小的土地；

With nuclear power, you might only need an area

如果用核能的話，

about the size of the palms of your hands.

也只需要雙掌張開來的面積；

With solar power, you’d need at least 0.3 square meters of land—

而太陽能則需要 0.3 平方公尺，

twice the size of a cafeteria tray.

大概是兩個餐廳托盤的大小。

Wind power would take roughly 7 square meters—

風力發電需要七平方公尺，

about half the size of a parking space— to power the bulb.

約半個停車位的空間， 來供電給這個燈泡。

When you consider the space needed to power cities, countries,

考慮到供電給城市、國家、 甚至是全世界的時候，

and the whole world, it adds up fast.

所需空間就會變得非常大。

Today, the world uses 3 trillion watts of electricity.

現在全世界總共需要三兆瓦的電力。

To power the entire world with only fossil fuels,

只用化石燃料供電給全世界的話，

you’d need at least about 1,200 square kilometers of space—

至少需要 1,200 平方公里的土地，

roughly the area of Grand Bahama island.

大概跟大巴哈馬島一樣大。

With nuclear energy, you’d need almost four times as much space at a minimum—

如果只用核能， 則需要至少四倍大的空間，

roughly 4,000 square kilometers, a little less than the area of Delaware.

約 4,000 平方公里， 稍微比德拉瓦州小一點。

With solar, you’d need at least 95,000 square kilometers,

假設使用太陽能， 至少要九萬五千平方公里，

approximately the area of South Korea.

大約是南韓國土的面積。

With wind power, you’d need two million— about the area of Mexico.

風力發電則需要兩百萬， 差不多是整個墨西哥的大小。

For each power source, there’s variability in how much power

對各種能源來說，

每平方公尺能產生的電力 雖然會有變化，

it can generate per square meter,

but these numbers give us a general sense of the space needed.

但這讓我們對需要的空間 能有基本的概念。

Of course, building energy infrastructure in a desert, a rainforest, a town,

當然，能源設施 蓋在沙漠、雨林、城鎮，

or even in the ocean are completely different prospects.

甚至是在海上，風景是完全不同的。

And energy sources monopolize the space they occupy to very different extents.

每種能源影響周邊土地的程度 也非常不一樣。

Take wind power.

拿風力發電來說，

Wind turbines need to be spread out— sometimes half a kilometer apart—

風機需要蓋的很分散， 有時候要相隔超過半公里，

so that the turbulence from one turbine

以免一台風機葉片產生的氣流，

doesn’t reduce the efficiency of the others.

降低其他風機的效率。

So, much of the land needed to generate wind power

因此大部分風力發電所需的土地，

is still available for other uses.

其實還能做其他的用途。

But the baseline amount of space still matters,

不過所需的基本空間大小還是很重要，

because cities and other densely populated areas have high electricity demands,

因為城市或人口密集區域 對電力的需求比較大，

and space near them is often limited.

且周圍的土地通常很有限。

Our current power infrastructure works best

以目前的電力基礎設施來講，

when electricity is generated where and when it’s needed,

比起將電力儲存起來或是從遠處輸送，

rather than being stored or sent across long distances.

於所在地即時產生 所需電力是最有效的。

Still, space demands are only part of the equation.

但是，空間需求只是其中的一環。

As of 2020, 2/3 of our electricity comes from fossil fuels.

直至 2020 年，我們的電力 有三分之二來自於化石燃料。

Every year, electricity generation is responsible for about 27%

每年排放的 500 多億噸 溫室氣體當中，

of the more than 50 billion tons of greenhouse gases

有 27% 左右是由發電而來，

we add to the atmosphere,

accelerating climate change and all its harms.

使氣候變遷及其產生的傷害加速惡化。

So although fossil fuels require the least space of our existing technologies,

所以儘管在現有技術中， 化石燃料需要的空間最小，

we can’t continue to rely on them.

但我們不能夠一直依賴它。

Cost is another consideration.

花費則是另外一個考量。

Nuclear plants don’t emit greenhouse gases and don’t require much space,

核電廠不會排放溫室氣體， 而且佔地也不大，

but they’re way more expensive to build than solar panels or wind turbines,

但興建成本比太陽能板 跟風車昂貴許多，

and have waste to deal with.

還有核廢料需要處理。

Renewables have almost no marginal costs—

再生能源跟火力發電廠不同，

unlike with plants powered by fossil fuels,

幾乎沒有邊際成本，

you don’t need to keep purchasing fuel to generate electricity.

你不需要持續購買燃料來發電，

But you do need lots of wind and sunlight,

但需要很多的風和陽光，

which are more available in some places than others.

這些資源會因為地點而有所不同。

No single approach will be the best option to power the entire world

要在減少溫室氣體排放的 同時提供電力給全世界，

while eliminating harmful greenhouse gas emissions.

並沒有哪一個是最好的答案。

For some places, nuclear power might be the best option

在有些地區要取代化石燃料，

for replacing fossil fuels.

核能可能是最佳的選擇。

Others, like the U.S., have the natural resources

但美國等其他地方 有足夠的自然資源，

to get most or all of their electricity from renewables.

有辦法大部分甚至全面 使用再生能源來供電。

And across the board, we should be working to make our power sources better:

整體來說，我們應該努力 讓這些能源更好：

safer in the case of nuclear,

讓核能更安全，

and easier to store and transport in the case of renewables.

讓再生能源的儲存和輸送更容易。