Coal burns in a furnace, which turns water into steam.

煤在爐子裡燃燒，把水變成蒸汽。

That steam spins a turbine, which activates a generator,

蒸汽帶動渦輪機旋轉，從而啟動發電機。

which pushes electrons through the wire.

它將電子推過電線。

This current propagates through hundreds of miles of electric cables

這種電流通過數百英里長的電纜傳播。

and arrives at your home.

並送到你的家裡。

All around the world, countless people are doing this every second—

在世界各地，無數的人每一秒鐘都在做這件事。

flipping a switch, plugging in, pressing an “on” button.

翻開開關，插上電源，按下 "開 "的按鈕。

So how much electricity does humanity need?

那麼人類需要多少電呢？

The amount we collectively use is changing fast,

我們集體使用的數量正在快速變化。

so to answer this question,

所以回答這個問題。

we need to know not just how much the world uses today,

我們需要知道的不僅僅是當今世界的使用量。

but how much we'll use in the future.

但未來我們會用多少。

The first step is understanding how we measure electricity.

第一步是瞭解我們如何測量電。

It's a little bit tricky.

這是一個有點棘手的問題。

A joule is a unit of energy,

焦耳是一種能量組織、部門。

but we usually don't measure electricity in just joules.

但我們通常不只用焦耳來測量電。

Instead, we measure it in watts.

相反，我們用瓦特來衡量它。

Watts tell us how much energy, per second, it takes to power something.

瓦特告訴我們，每秒鐘需要多少能量來驅動某樣東西。

One joule per second equals one watt.

每秒鐘一個焦耳等於一個瓦特。

It takes about .1 watts to power a smart phone,

智能手機的電量大約需要0.1瓦。

a thousand to power your house, a million for a small town,

一千塊錢給你的房子供電，一百萬給一個小鎮。

and a billion for a mid-size city.

和一箇中型城市的10億。

As of 2020, it takes 3 trillion watts to power the entire world.

截至2020年，需要3萬億瓦特的電力來為整個世界供電。

But almost a billion people don't have access to reliable electricity.

但有近10億人無法獲得可靠的電力。

As countries become more industrialized and more people join the grid,

隨著國家工業化程度的提高，越來越多的人加入到電網中來。

electricity demand is expected to increase about 80% by 2050.

預計到2050年，電力需求將增加約80%。

That number isn't the complete picture.

這個數字並不完整。

We'll also have to use electricity in completely new ways.

我們還得用全新的方式來使用電力。

Right now, we power a lot of things by burning fossil fuels,

現在，我們通過燃燒化石燃料來驅動很多東西。

emitting an unsustainable amount of greenhouse gases

排放不可持續的溫室氣體的國家

that contribute to global warming.

導致全球變暖的因素。

We'll have to eliminate these emissions entirely

我們必須完全消除這些排放

to ensure a sustainable future for humanity.

以確保人類的可持續未來。

The first step to doing so, for many industries,

做到這一點的第一步，對於很多行業來說。

is to switch from fossil fuels to electric power.

就是要從化石燃料轉為電力。

We'll need to electrify cars,

我們需要讓汽車電氣化。

switch buildings heated by natural gas furnaces to electric heat pumps,

將天然氣爐加熱的建築物改為電熱泵；

and electrify the huge amount of heat used in industrial processes.

並對工業過程中使用的大量熱量進行電氣化處理。

So all told, global electricity needs could triple by 2050.

所以說，到2050年，全球電力需求可能增加三倍。

We'll also need all that electricity to come from clean energy sources

我們還需要所有的電力來自於清潔能源

if it's going to solve the problems caused by fossil fuels.

如果它能解決化石燃料造成的問題。

Today, only one third of the electricity we generate comes from clean sources.

今天，我們生產的電力中只有三分之一來自清潔能源。

Fossil fuels are cheap and convenient, easy to ship,

化石燃料便宜方便，便於運輸。

and easy to turn into electricity on demand.

並很容易變成按需供電。

So how can we close the gap?

那麼，如何才能縮小差距呢？

Wind and solar power work great for places with lots of wind and sunshine,

風力和太陽能對於風和陽光充足的地方來說，效果非常好。

but we can't store and ship sunlight or wind the way we can transport oil.

但我們不能像運輸石油那樣儲存和運輸陽光或風。

To make full use of energy from these sources at other times or in other places,

在其他時間或其他地方充分利用這些來源的能源。

we'd have to store it in batteries

我們必須把它儲存在電池裡

and improve our power grid infrastructure to transport it long distances.

並完善我國電網基礎設施，遠距離輸送。

Meanwhile, nuclear power plants use nuclear fission

同時，核電站使用核裂變

to generate carbon-free electricity.

以產生無碳電力。

Though still more expensive than plants that burn fossil fuels,

雖然還是比燃燒化石燃料的工廠更貴。

they can be built anywhere

遍地開花

and don't depend on intermittent energy sources like the sun or wind.

而不依賴太陽或風等間歇性能源。

Researchers are currently working to improve nuclear waste disposal

目前，研究人員正在努力改善核廢料的處理方式。

and the safety of nuclear plants.

以及核電站的安全問題。

There's another possibility we've been trying to crack since the 1940s:

還有一種可能，我們從20世紀40年代就開始嘗試破解。

nuclear fusion.

核聚變。

It involves smashing light atoms together, so they fuse,

它包括將光原子粉碎在一起，使它們融合。

and harnessing the energy this releases.

並利用這釋放的能量。

Accidents aren't a concern with nuclear fusion,

核聚變不需要擔心事故。

and it doesn't produce the long-lived radioactive waste fission does.

而且它不會產生長壽命的放射性廢物 裂變做。

It also doesn't have the transport concerns

它也沒有運輸的問題

associated with wind, solar, and other renewable energy sources.

與風能、太陽能和其他可再生能源有關的。

A major breakthrough here could revolutionize clean energy.

這裡的重大突破可能會給清潔能源帶來革命性的變化。

The same is true of nuclear fission, solar, and wind.

核裂變、太陽能、風能也是如此。

Breakthroughs in any of these technologies,

這些技術中的任何一項取得突破。

and especially in all of them together, can change the world:

尤其是在所有的人一起，可以改變世界。

not only helping us triple our electricity supply,

不僅幫助我們增加了三倍的電力供應。

but enabling us to sustain it.

但使我們能夠維持它。