is hooked up to the Southern California power grid

與南加州電網相連

and can provide 250 million watts of power,

並可提供2.5億瓦的電力。

or enough to power about 250,000 homes.

或足夠為約25萬戶家庭供電。

But it's actually not the biggest battery in the world:

但它其實不是世界上最大的電池。

these lakes are.

這些湖泊是。

Wait— how can a pair of lakes be a battery?

等等--一對湖泊怎麼可能是電池？

To answer that question, it helps to define a battery:

要回答這個問題，有助於定義電池。

it's simply something that stores energy and releases it on demand.

它只是一種儲存能量並按需釋放的東西。

The lithium-ion batteries that power our phones, laptops, and cars

為我們的手機、筆記本電腦和汽車提供動力的鋰離子電池。

are just one type.

只是一種類型。

They store energy in lithium ions.

它們將能量儲存在鋰離子中。

To release the energy, the ions are separated from their electrons,

為了釋放能量，離子與電子分離。

then rejoined at the other end of the battery

然後再在電池的另一端連接起來

as a new molecule with lower energy.

作為一個能量較低的新分子。

How do the two lakes store and release energy?

兩湖是如何儲存和釋放能量的？

First, one is 300 meters higher than the other.

首先，一個比另一個高300米。

Electricity powers pumps that move billions of liters of water

電力驅動水泵移動數十億公升的水

from the lower lake to the higher one.

從低處的湖泊到高處的湖泊。

This stores the energy by giving the water extra gravitational potential energy.

這通過給水額外的重力勢能來儲存能量。

Then, when there's high demand for electricity,

然後，當電力需求量大的時候。

valves open, releasing the stored energy by letting water flow downhill

閥門打開，通過讓水往下流來釋放儲存的能量。

to power 6 giant turbines that can generate 3 billion watts of power

為6臺巨大的渦輪機提供動力，可產生30億瓦的電力。

for 10 hours.

10小時。

We're going to need more and more giant batteries.

我們會需要越來越多的巨型電池。

That's because right now, generating enough electricity to power the world

這是因為現在，發電量足以為世界提供電力。

produces an unsustainable amount of greenhouse gas:

產生了不可持續的溫室氣體量。

14 billion tons per year.

每年140億噸。

We'll need to get that number down to net-zero.

我們需要把這個數字降到淨值零。

But many clean energy sources can't produce electricity 24/7.

但很多清潔能源不能24小時不間斷地發電。

So to make the switch, we need a way to store the electricity until it's needed.

所以要想轉換，我們需要一種方法來儲存電能，直到需要的時候。

That means we need grid-scale batteries:

這意味著我們需要電網規模的電池。

batteries big enough to power multiple cities.

足夠大的電池為多個城市供電。

Unfortunately, neither of the giant batteries we've talked about so far

不幸的是，到目前為止，我們所談及的巨型電池都沒有。

can solve this problem.

可以解決這個問題。

The two lakes setup requires specific geography, takes up a lot of land,

兩湖設置需要特定的地理環境，佔用大量土地。

and has high upfront costs to build.

並具有較高的前期建設成本。

The giant lithium-ion battery in California, meanwhile,

加州的巨型鋰離子電池，同時。

can power about 250,000 homes, yes, but only for an hour.

可以為25萬戶家庭供電，是的，但只能維持一個小時。

Lithium-ion batteries are great for things that don't use a lot of power.

鋰離子電池很適合用電量不大的東西。

But to store a lot of energy, they have to be huge and heavy.

但要儲存大量的能量，它們必須是巨大而沉重的。

That's why electric planes aren't a thing:

這就是為什麼電動飛機不是一個東西。

the best electric plane can only carry two people

電動飛機最好的也只能載兩個人

for about 1,000 kilometers on one charge,

一次充電可行駛約1000公里。

or its batteries would be too heavy to fly.

否則它的電池會太重，無法飛行。

A typical commercial jet can carry 300 people over 14,000 km before refueling.

一架典型的商用噴氣機在加油前可載300人飛行14000公里。

Lithium-ion batteries also require certain heavy metals to make.

鋰離子電池也需要某些重金屬來製造。

These resources are limited, and mining them often causes environmental damage.

這些資源是有限的，開採這些資源往往會造成環境破壞。

Inventors all over the world are rising to the challenge

全世界的發明家都在迎接挑戰。

of making batteries that can meet our needs—

製造能滿足我們需求的電池

many of them even weirder than the two lakes.

其中很多甚至比兩湖更詭異。

One company is building a skyscraper battery.

有一家公司正在打造摩天大樓電池。

When the sun is shining, a crane powered by solar energy

陽光燦爛的時候，用太陽能驅動的起重機

piles blocks on top of each other in a tower.

將積木疊加在塔上。

At night, the cranes let gravity pull the blocks down

夜晚，吊車讓重力把積木拉下來。

and use the resulting power to spin generators.

並利用所產生的電力來旋轉發電機。

Though there have been some early setbacks,

雖然早期也有一些挫折。

another promising approach involves heating up salts until they melt.

另一種很有前途的方法是將鹽類加熱至融化。

The molten salt can be stored until there's a high demand for electricity,

這些熔鹽可以儲存起來，直到有大量的電力需求。

then used to boil water.

然後用來燒水。

The steam can power turbines that generate electricity.

蒸汽可以驅動渦輪機發電。

Another idea: bio-batteries made from paper, powered by bacteria,

另一個想法：用紙做的生物電池，由細菌提供動力。

and activated by spit.

並被唾液激活。

Bacteria release energy in the form of electrons when they metabolize glucose,

細菌在代謝葡萄糖時以電子的形式釋放能量。

and at least one species of bacteria can transfer those electrons

而至少有一種細菌可以轉移這些電子

outside its cells, completing a circuit.

在其細胞外，完成一個電路。

While these batteries won't power a city, or even a house,

雖然這些電池無法為一個城市，甚至一棟房子供電。

they don't have the waste and cost concerns of traditional batteries.

它們沒有傳統電池的浪費和成本問題。

From vast mountain lakes to microscopic bacteria,

從浩瀚的高山湖泊到微觀的細菌。

from seawater batteries that bypass the need for heavy metals

海水電池，不需要重金屬

to nuclear batteries that power deep space missions,

到為深空任務提供動力的核電池。

we're constantly rethinking what a battery can be.

我們不斷地在重新思考電池可以是什麼。

The next unlikely battery could be hiding in plain sight—

下一個不太可能的電池可能就藏在眾目睽睽之下--。

just waiting to be discovered and help us achieve a sustainable future.

就等著被發現，幫助我們實現可持續發展的未來。