How do wind turbines work? - Rebecca J. Barthelmie and Sara C. Pryor

譯者: Helen Chang 審譯者: Amanda Zhu

Every 24 hours, wind generates enough kinetic energy

每 24 小時，風所產生的動能

to produce roughly 35 times more electricity than humanity uses each day.

約超出人類每日所需電力的 35 倍。

And unlike coal or oil, this resource is totally renewed each day.

與煤炭或石油不同， 這種資源每日完全再生。

So how can we harness this incredible amount of energy,

那麼，我們能如何駕馭 如此大量的能源，

and is it possible to create a world powered entirely by wind?

讓風能滿足全世界所需呢？

The basic principle of wind energy is simple.

風能的基本原則很簡單。

A series of sails or blades mounted around a rotor catch the wind

風吹動一系列的葉片轉動馬達

and translate its kinetic energy into rotational energy.

把風的動能轉換為旋轉能。

Traditional windmills use that rotational energy to grind wheat or pump water.

傳統的風車用旋轉能磨麥或抽水。

But in modern wind turbines, it turns a generator that creates electricity.

但現代的風力渦輪 轉動發電機來產生電力。

This conversion from wind to rotational energy to electricity

這種從風轉換成旋轉能再轉成的電力

has defined wind turbines since their invention in the late 19th century.

自 19 世紀後期被發明之後 就定義了風力渦輪機。

And there are three primary factors that determine just how much energy

有三個主要因素決定

它們能夠產生多少能量： 葉片的大​​小和方向、

they can produce: the size and orientation of the blades,

the blade’s aerodynamic design, and the amount of wind turning the rotor.

葉片的空氣動力學設計 以及轉動轉子的風量。

First up, blade orientation.

首先是葉片的定向。

Wind turbines can be designed with their rotor

風力渦輪機的轉子設計

on a vertical axis or a horizontal axis.

可在垂直軸或水平軸上。

Vertical blades can pick up wind coming from any direction,

任何方向的風都能轉動垂直的葉片，

but with much less efficiency than horizontal axis rotors.

但效率比水平轉子要低得多。

Horizontal designs allow blades to capture the wind’s full force

水平的設計讓葉片捕獲風的全部力量

by tracking the wind’s direction and turning to face it.

做法是追踪風的方向，直接面對它。

This turning process is called yawing,

這種轉向的過程稱為偏轉，

and older windmills achieved it through manual monitoring.

舊式的風車得靠人工監控。

Today, wind sensors and computer systems automatically adjust the blades

如今風的傳感器和計算機系統 會自動調整葉片，

with expert precision to capture as much energy as possible.

盡可能精確地捕獲最多的能量。

Outside rotor orientation,

轉子的方向除外，

the blades themselves need to be shaped to maximize efficiency.

葉片本身得要做成 把效率最大化的形狀。

While early designs used flat blades,

早期的設計使用扁平的葉片，

modern blades are curved like airplane wings.

現代的彎曲葉片像是飛機的機翼。

Wind travels faster over the curved surface,

吹過彎曲葉片表面的風速較快，

creating a low-pressure pocket above the blade that forces it upwards.

在葉片上方產生低壓區， 迫使葉片上抬。

Since the amount of lift depends on the angle

由於提升量取決於

at which the wind is moving relative to the blade,

風相對於葉片的移動角度，

modern blades also incorporate a twist,

現代的葉片還帶有扭力，

optimizing how much of the blade can cut into the wind.

能優化葉片切入風的量。

Made of fiberglass and resin layers, these blades are strong enough

這些由玻璃纖維 和樹脂層製成的葉片夠牢固，

to operate through rain, lightning, and blistering sunlight for over 20 years.

能在雨、閃電中和烈日照射下 使用超過 20 年。

Even with aerodynamic blades and a horizontal rotor,

即使有符合空氣動力學 設計的葉片和水平的轉子，

a wind turbine can only capture wind if it's in a windy environment.

風力渦輪機只能在風大的環境中 才能夠捕獲風能。

Wind speeds typically increase the higher into the atmosphere you travel.

通常於大氣層越高處，風速就越強。

So today, most turbines are well over 100 meters tall,

所以當今的大多數渦輪機 超過 100 米高，

with equally large rotor diameters.

還具有大直徑的轉子。

A turbine of this height and size can capture a huge amount of wind,

一座如此高和大尺寸的渦輪機 能捕獲大量的風，

generating enough electricity every year to power 750 American homes.

產生的電力夠為 750 戶美國家庭供電一年。

A wind farm of 200 similarly sized turbines

配備 200 個類似大小渦輪機的風電場

could power over 150,000 American homes— or twice as many European homes—

可以為超過 15 萬美國家庭—— 或兩倍數目的歐洲家庭——

for an entire year.

供電一整年。

Offshore wind farms contain an even greater number of even larger turbines.

離岸的風電場配備著 數量更多且更大的渦輪機。

In 2019, the largest wind turbine ever built

截止當時為止所造的 最大風力發電機，2019 年

began operating off the coast of the Netherlands.

在荷蘭沿海地區開始作業。

With a rotor diameter of 220 meters, just one of these turbines

它的轉子直徑為 220 米， 僅此一台

can meet the annual power needs of 16,000 European households.

就足以供應 16,000 個 歐洲家庭的一年用電。

Despite its amazing potential, wind energy still faces challenges.

儘管具有巨大的潛力， 風能仍面對挑戰。

Wind may be a free and unlimited fuel,

雖然風能免費且取之不盡，

but no matter how large or efficient a turbine is

但不管渦輪多大或多有效率，

there's a mathematical limit to how much wind it can convert into electricity.

風能轉化為電能仍有一定的上限。

German physicist Albert Betz calculated

德國物理學家阿爾伯特·貝茨算出

that since some wind must remain to keep the blades spinning,

由於必須讓葉片保持旋轉，

a turbine can only ever capture 59.3% of the wind’s energy.

渦輪機至多捕獲 59.3％ 的風能。

Additionally, some people feel turbines disrupt natural scenery,

此外，有些人認為 渦輪機破壞自然的風光，

and wind energy’s intermittent availability

加上風能只間歇可用，

can make it difficult to integrate into electrical grids.

使其難以被整合入電網。

But even with these challenges, modern wind turbines have made wind energy

但即使有這些挑戰， 現代風力渦輪機已使風能

the most efficient and inexpensive source of electricity.

成為最高效、最便宜的電力來源。

Wind turbines already provide essential energy for communities around the world.

風力渦輪機已為世界各地的社區 提供必不可少的能源。

And for many farmers, hosting a wind turbine

對許多農民而言， 在農地上架設風力發電機

can be a reliable source of additional income.

是可靠的額外收入來源。

With continued improvements in wind forecasting,

持續不斷改進的風場預報、

electrical grid infrastructure and energy storage,

電網基礎設施和能量儲存，

wind power might blow away all our energy problems.

或許風能將會消弭 我們所有的能源問題。