Why don’t we cover the desert with solar panels? - Dan Kwartler

Translator: H.M. Remi Reviewer: 潘 可儿

Every day, the sands of the Sahara Desert reach temperatures up to 80° Celsius.

每一日，撒哈拉沙漠嘅沙溫度 可高達攝氏80度

Stretching over roughly nine million square kilometers,

沙漠幅員約九百萬平方公里

this massive desert receives about 22 million terawatt hours of energy

如此廣闊嘅沙漠 每年吸收來自太陽嘅能量

from the Sun every year.

高達約二千二百萬太瓦時

That’s well over 100 times more energy than humanity consumes annually.

係人類每年能源消耗量 總和嘅一百倍

So, could covering the desert with solar panels solve our energy problems for good?

我哋可唔可以通過 喺沙漠鋪滿太陽能板

嚟解決能源問題呢？

Solar panels work when light particles hit their surface with enough energy

光子接觸太陽能板 且能量夠強嘅時候

to knock electrons out of their stable bonds.

就會拆散電子間嘅化學鍵 令電子變得不穩定

On their journey back to stability, these electrons produce electricity.

當電子開始恢復平穩 就會產生電力

However, there’s a limit to how much power panels can generate.

不過，發電嘅能力係有限嘅

Solar panels can only interact with certain wavelengths of light,

太陽能板只會對 特定波長嘅光有反應

making it impossible to convert over half the sunlight they receive.

超過一半嘅陽光 未能轉化為電能

And even light particles they can convert often bounce off them

就算適合嘅光子 未碰到電子之前

without ever hitting an electron.

就已經被反彈走了

But thanks to clever scientists and engineers

好彩，聰明嘅科學家、工程師

and substantial government investment,

加上政府不斷嘅資金支持

solar panels are generating more electricity than ever.

太陽能板嘅產電效能 有增無減

Anti-reflective coatings and patterns on the panels’ surface

太陽能板表面有 防反射塗層、紋理

create more opportunities for incoming light particles to hit electrons.

增加光子接觸電子的機會

These techniques have increased commercial solar panel efficiency

依啲技術大大提高咗 太陽能板嘅商業效益

from the low-teens to 25%,

實驗中嘅太陽能板效能

從百分之十幾到百分之二十五 提升至百分之四十七

with experimental models reaching up to 47%.

What’s more, solar has gotten 89% cheaper over the last decade,

而且，太陽能已經比十年前 平咗百分之八十九

thanks in part to global supply chains for other technologies

有咁嘅成績，亦有賴其他科技 嘅環球供應鏈都開始應用

that use the same materials.

相同嘅物料

Together, these factors have made solar power

種種因素令太陽能

the cheapest source of electricity on Earth.

成為地球上最便宜嘅電力

Countries including India, China, Egypt, and the US,

多個國家，包括印度、中國 埃及同美國

have already taken these new panels into the desert.

都已經喺境內沙漠地區 建設太陽能板

Their massive solar farms range from 15 to 56 square kilometers,

依啲巨型太陽能發電站 佔地 15 至 56 平方公里

and when the sun is high in the sky,

只要太陽喺天上高高掛起

these plants can provide energy

依啲發電站就可以生產電力

for hundreds of thousands of local residents.

供給當地成千上萬嘅居民使用

But these farms also get extremely hot.

但依啲發電站 溫度亦極高

Light that solar cells don’t convert or reflect is absorbed as heat,

未能被光伏電池 轉化或反射嘅陽光

變成熱能被吸收 降低太陽能板嘅效能

which reduces a panel’s efficiency.

And the cooling systems employed by many farms can use huge amounts of energy

眾多發電站嘅冷卻系統 譬如風扇同流水

powering fans or moving water to maintain optimal temperatures.

需要消耗大量能源去運作 以維持最佳溫度

Even with these systems, solar panels in the desert absorb far more heat

就算有冷卻系統 相比喺一般荒地

than the natural sandy environment.

沙漠嘅太陽能板 要承受更高溫度

This hasn’t been a problem on the scale of existing solar farms.

雖然依個問題暫時未對 太陽能發電站造成影響

But if we tried to cover the Sahara,

但如果我哋嘗試 攞太陽能板覆蓋撒哈拉

this effect could create massive changes in the region's climate.

就有可能會對呢個地區嘅氣候 造成重大影響

Constructing solar farms already disrupts local ecosystems,

建造太陽能發電站 已經擾亂當地生態

but a plant of this scale could dramatically transform

如此龐大嘅太陽能發電站

the desert landscape.

一定會大規模改變 整個沙漠嘅地貌

Thankfully, solar panels aren’t our only option.

好彩，太陽能板 唔係唯一嘅選擇

And some of the largest solar plants in the world are trying a new approach:

世界最大嘅幾個太陽能發電站 正喺度嘗試一個新方法

giant mirrors.

巨型鏡子

Morocco’s Noor Power Plant,

摩洛哥嘅瓦爾扎扎特太陽能發電站

which will eventually cover roughly 30 square kilometers of the Sahara,

建成後將會覆蓋撒哈拉 約三十平方公里

is a concentrated solar power plant.

係個聚光太陽能熱發電站

This design reflects light onto a receiver,

設計透過反射光到接收塔

which converts that energy to heat, and then electricity.

接受塔再將光能轉化為熱能 嚟生產電力

These mirrors still create a dangerous temperature shift for local wildlife,

雖然鏡子會產生危險高溫 對當地野生動物仍有影響

but they have less potential to transform the landscape.

但對地貌嘅影響小滴

And since it takes time for the materials being heated to cool off,

加上物料需時冷卻

these plants often continue producing electricity past sunset.

所以就算喺太陽落山之後 發電站都仲可以繼續發電

Whether they use panels or mirrors,

無論係太陽能板 定係鏡子

industrial solar farms are often easy to fit into existing energy infrastructure.

工業太陽能發電站 通常都好容易同已有發電設施接軌

However, getting their electricity beyond local power grids is much more difficult.

但要超越本來能源網 將電力傳遞到更遠，就困難得多

Some countries are working on ways to connect electric grids across the globe.

有啲國家正想辦法 將本土能源網接通世界

And many farm store energy in massive batteries,

有好多發電站 將能源儲存喺巨型電池中

or convert their electricity into clean gas that can be used later.

或者將電力 變成清潔氣體能源備用

But right now, these techniques are still too expensive and inefficient to rely on.

但因價格高、效益低 技術仲未能獨擔大旗

Worse still, industrial renewables can share some of the same problems

更差嘅係，工業用再生能源 其實同化石燃料

as fossil fuels,

有共同嘅問題

relying on destructive mining operations and carbon-emitting global supply chains.

兩種能源都太依賴破壞性採掘 以及造成全球碳排放連鎖反應

Fortunately, solar can exist on many scales,

好彩嘅係，太陽能喺規模大小上 很有彈性

from industrial solar farms to smaller installations

從工業用太陽能農場 到同獨棟大廈、農業社區供電嘅小型裝置

that power individual buildings and rural communities.

These projects can supplement energy use or provide a passive source of energy

依啲設施可提供能源 或者同電網外嘅設施被動發電

for regions off the grid.

And since solar panels rely on a few simple components,

亦由於太陽能板組成部件簡單

they’re quick to install and relatively easy to update.

安裝速度快 更新都相對容易

In fact, it’s this flexibility that enabled solar

事實上，正係太陽能板嘅高度彈性

to become so cheap and ubiquitous over the last decade.

令佢喺近十年變得 咁平、咁普遍

So if we want to keep up with humanity's rising energy use,

所以如果我哋要追上人類 日益增長嘅能源需求

we'll need answers both big and small.

太陽能板無論大細 都一樣咁重要