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

翻译人员: KIWI KIWI 校对人员: Thomas Tam

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

每天，撒哈拉沙漠的地表温度 高达80摄氏度。

Stretching over roughly nine million square kilometers,

绵延面积约九百万平方千米，

this massive desert receives about 22 million terawatt hours of energy

这片巨大的沙漠，

每年来自太阳， 能接收两千两百万太瓦时的能源。

from the Sun every year.

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

远超人类每年 消耗能源的一百倍。

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

那么，用太阳能电池板覆盖撒哈拉沙漠 能解决我们的能源问题吗？

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

当光子撞击在电板表面的能量足够大时， 太阳能电池板就会工作，

to knock electrons out of their stable bonds.

将电子从其稳定的连接中敲出。

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

回归稳态的过程中，电子会产生电流。

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

但是，太阳能电板 产生的能量是有限的，

Solar panels can only interact with certain wavelengths of light,

因为电板只对特定波长的光线有效，

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

它们只能转化接受光能的一半。

And even light particles they can convert often bounce off them

即使它们可以转换的光粒子 也经常从它们身上反弹，

without ever hitting an electron.

而非撞击到电子。

But thanks to clever scientists and engineers

不过，得益于科学家和工程师的才智，

and substantial government investment,

以及政府的持续投入，

solar panels are generating more electricity than ever.

太阳能电板正产生着前所未有的电能。

Anti-reflective coatings and patterns on the panels’ surface

电板表面的防反射涂层和图案，

create more opportunities for incoming light particles to hit electrons.

使到达的光子更有可能撞击到电子。

These techniques have increased commercial solar panel efficiency

这些技术让商用太阳能电板的效率

from the low-teens to 25%,

从低双位数提高到25%，

with experimental models reaching up to 47%.

在一些实验性模型上甚至高达47%。

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

近十年来更重要的是， 太阳能发电的成本降低了89%，

thanks in part to global supply chains for other technologies

这部分归功于其他技术

that use the same materials.

使用相同材料的全球供应链。

Together, these factors have made solar power

这些因素加在一起，

使得太阳能成为地球上 最廉价的电力来源。

the cheapest source of electricity on Earth.

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

包括印度，中国，埃及 和美国在内的一些国家，

have already taken these new panels into the desert.

已经将这些新型太阳能电板 安装到了沙漠上。

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

这些庞大的太阳能发电厂 面积从15到56平方千米，

and when the sun is high in the sky,

当太阳出来了，

这些覆盖能提供能量

these plants can provide energy

for hundreds of thousands of local residents.

给成千上万当地居民。

But these farms also get extremely hot.

但是这些发电厂的温度会非常高。

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

太阳能电池不能转换 或反射的光被吸收为热量，

which reduces a panel’s efficiency.

这降低了电池板的效率。

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

许多农场使用的冷却系统 可以使用大量的能量

powering fans or moving water to maintain optimal temperatures.

为风扇或流动的水提供动力， 以保持最佳温度。

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

即使有了这些系统， 沙漠中的太阳能电池板吸收的热量，

than the natural sandy environment.

也远远超过自然沙质环境。

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

在现有太阳能发电厂规模上， 这并不是个问题；

But if we tried to cover the Sahara,

但如果我们试图覆盖撒哈拉沙漠，

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

这种影响可能会造成 该地区气候的巨大变化。

Constructing solar farms already disrupts local ecosystems,

建造太阳能农场已经 破坏了当地的生态系统，

but a plant of this scale could dramatically transform

这种规模的工厂可以极大地改变

the desert landscape.

沙漠的景观。

Thankfully, solar panels aren’t our only option.

谢天谢地，太阳能电池板 不是我们唯一的选择。

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

世界上一些最大的太阳能发电厂 正在尝试一种新方法：

giant mirrors.

巨型镜子。

Morocco’s Noor Power Plant,

摩洛哥的努尔发电厂，

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

最终将覆盖约30平方千米的撒哈拉沙漠，

is a concentrated solar power plant.

是一座集中的太阳能发电厂。

This design reflects light onto a receiver,

这种设计将光线反射到接收器上，

which converts that energy to heat, and then electricity.

它将能量转化为热能， 然后转化为电能。

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

这些镜子仍然会对当地野生动物 造成危险的温度变化，

but they have less potential to transform the landscape.

但它们改变景观的潜力较小。

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

由于被加热的材料需要时间冷却，

these plants often continue producing electricity past sunset.

这些工厂通常会在日落后继续发电。

无论使用太阳能电池板还是镜子，

Whether they use panels or mirrors,

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

工业太阳能发电厂 通常很容易融入现有能源基础设施。

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

然而，将电力输送到 当地电网以外的地方要困难多了。

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

一些国家正在研究连接全球电网的方法。

And many farm store energy in massive batteries,

许多农场将能量储存在大型电池中，

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

或将其电能转换成 可供日后使用的清洁气体。

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

但目前，这些技术仍然是 过于昂贵和低效，是无法依赖的。

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

更糟糕的是，工业化的可再生能源 可能与化石燃料

as fossil fuels,

面临同样的问题，

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

依赖于破坏性的采矿作业 和碳排放的全球供应链。

Fortunately, solar can exist on many scales,

幸运的是，太阳能可以以多种规模存在，

from industrial solar farms to smaller installations

从工业太阳能农场到为单个建筑

that power individual buildings and rural communities.

和农村社区供电的小型装置。

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

这些项目可以补充能源使用， 或为电网以外的地区

for regions off the grid.

提供被动能源。

And since solar panels rely on a few simple components,

由于太阳能电池板 依赖于几个简单的组件，

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

它们安装迅速，相对容易更新。

In fact, it’s this flexibility that enabled solar

事实上，正是这种灵活性使得太阳能

to become so cheap and ubiquitous over the last decade.

在过去十年中变得如此廉价和普遍。

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

所以，如果我们想跟上 人类不断增长的使用能源，

we'll need answers both big and small.

会需要得着大大小小的答案。