Can 100% renewable energy power the world? - Federico Rosei and Renzo Rosei

翻译人员: Huang Haisu 校对人员: Zhuo Hao

Every year, the world uses 35 billion barrels of oil.

每年，全世界会用掉 350 亿桶油。

This massive scale of fossil fuel dependence pollutes the Earth

这种对化石燃料的大规模依赖 会污染我们的地球，

and it won't last forever.

而且不会永远持续下去。

Scientists estimate that we've consumed about 40% of the world's oil.

科学家估计我们已经使用了 大约世界总油量的百分之四十。

According to present estimates,

根据目前的估计，

at this rate, we'll run out of oil and gas in 50 years or so,

以这个速度进行下去，我们将在 大约 50 年后用光总有的油和气，

and in about a century for coal.

在一个世纪后用尽所有的煤炭。

On the flip side, we have abundant sun, water, and wind.

另一方面，我们拥有 充足的阳光、水和风。

These are renewable energy sources,

这些是可再生能源，

meaning that we won't use them up over time.

意思是无论多久， 我们都不会用尽这些资源。

What if we could exchange our fossil fuel dependence

如果我们可以把对化石燃料的依赖

for an existence based solely on renewables?

换成仅靠可再生能源 的存在方式会是什么样呢？

We've pondered that question for decades,

几十年来，我们一直在思考那个问题，

and yet, renewable energy still only provides about 13% of our needs.

然而，可再生能源仍只能满足 我们对能源需求的大约百分之十三。

That's because reaching 100% requires renewable energy that's inexpensive

那是因为，要达到百分之百的利用率， 可再生能源需要更廉价，

and accessible.

而且要容易得到。

This represents a huge challenge,

这是项强大的挑战，

even if we ignore the politics involved and focus on the science and engineering.

即使我们忽略政治的参与， 集中在科学和工程上面。

We can better understand the problem by understanding how we use energy.

我们可以通过我们如何 使用能源来理解这个问题。

Global energy use is a diverse and complex system,

全球能源使用是 一个多样而且复杂的系统，

and the different elements require their own solutions.

并且不同的元素需要 个性化的解决方式。

But for now, we'll focus on two of the most familiar in everyday life:

但是现在，我们将集中于 每日生活中最熟悉的两项：

electricity and liquid fuels.

电能和液体燃料。

Electricity powers blast furnaces, elevators, computers,

电能为高炉、电梯、电脑，

and all manner of things in homes, businesses, and manufacturing.

还有所有家里、企业和制造业需要 的各个方面提供能量。

Meanwhile, liquid fuels play a crucial role

同时，液体燃料起到了关键的作用，

in almost all forms of transportation.

主宰差不多所有方式的交通。

Let's consider the electrical portion first.

让我们先来考虑电的部分。

The great news is that our technology is already advanced enough

好消息是，我们的技术已经发展到了

to capture all that energy from renewables,

可以捕获从可再生资源那里得到的能量，

and there's an ample supply.

而且这种供给资源十分充足。

The sun continuously radiates

太阳持续放射

about 173 quadrillion watts of solar energy at the Earth,

大约 173 万亿瓦特太阳能到地球，

which is almost 10,000 times our present needs.

这是大约我们目前需要的 1 万倍。

It's been estimated that a surface that spans several hundred thousand kilometers

据估计，几十万公里长的表面

would be needed to power humanity at our present usage levels.

应该足够提供我们人类 目前使用水平的能量。

So why don't we build that?

那为什么我们不去建造呢？

Because there are other hurdles in the way,

因为有其他阻碍，

like efficiency

例如效率

and energy transportation.

和能源运输。

To maximize efficiency,

为了把效率最大化，

solar plants must be located in areas with lots of sunshine year round,

太阳能工厂必须建在 长年有充足阳光的地区，

like deserts.

例如沙漠。

But those are far away from densely populated regions

但是那些地区离能量需求很高

where energy demand is high.

的人口密集地区很远。

There are other forms of renewable energy we could draw from,

我们还有其他可再生资源可以考虑，

such as hydroelectric,

例如水力电气，

geothermal,

地热

and biomasses,

和生物质，

but they also have limits based on availability and location.

但是它们也有可获取性和地域的限制。

In principle, a connected electrical energy network

原则上讲，一个相连的电能网络

with power lines crisscrossing the globe

通过在全球纵横交错的电线连接

would enable us to transport power from where it's generated

可以让我们把电从发电地

to where it's needed.

运输到用电的地方。

But building a system on this scale faces an astronomical price tag.

但是建造这种规模的系统需要 配备的价格标签却是个天文数字。

We could lower the cost by developing advanced technologies

我们可以通过发展高科技来降低成本，

to capture energy more efficiently.

以更有效率地捕获能源。

The infrastructure for transporting energy would also have to change drastically.

运输能源需要的基础设施也 不得不发生巨大的改变。

Present-day power lines lose about 6-8% of the energy they carry

当今的电线会损失 百分之六到八的运输电能，

because wire material dissipates energy through resistance.

是因为电线材料会通过电阻耗散能量。

Longer power lines would mean more energy loss.

电线越长意味着丢失的能量越多。

Superconductors could be one solution.

超导体可以是一种解决方式。

Such materials can transport electricity without dissipation.

这种材料可以在没有能量耗散 的情况下运电。

Unfortunately, they only work if cooled to low temperatures,

不幸的是，它们只在低温环境下工作，

which requires energy and defeats the purpose.

这就需要额外的能量来 控制温度，结果适得其反。

To benefit from that technology,

为了在这个技术上获益，

we'd need to discover new superconducting materials

我们将需要发现可以在室温下工作

that operate at room temperature.

的新型超导体材料。

And what about the all-important, oil-derived liquid fuels?

那基于石油的重要液体燃料怎么样呢？

The scientific challenge there is to store renewable energy

它的科学挑战是把可再生能源

in an easily transportable form.

以容易运输的方式储存。

Recently, we've gotten better at producing lithium ion batteries,

近来，我们已经在生产 锂离子电池方面大有进步，

which are lightweight and have high-energy density.

它很轻而且拥有高能量密度。

But even the best of these store about 2.5 megajoules per kilogram.

但即使是最好的锂离子电池 储存的能量，每千克也只有 2.5 兆焦耳。

That's about 20 times less than the energy in one kilogram of gasoline.

比一千克的石油提供的能量 低大约 20 倍。

To be truly competitive, car batteries would have to store much more energy

要真正有竞争力，车用电池 需要储存更多的能量，

without adding cost.

而且不增加成本。

The challenges only increase for bigger vessels, like ships and planes.

随着载体变大，挑战也就越大， 例如：船只和飞机。

To power a cross-Atlantic flight for a jet,

给一架喷气式飞机提供 横跨大西洋飞行的能量，

we'd need a battery weighing about 1,000 tons.

我们需要一个重约 1000 吨的电池。

This, too, demands a technological leap towards new materials,

这个问题也需要技术上 的创新来发展新材料，

higher energy density,

拥有更高的能量密度

and better storage.

和更好的储存方式。

One promising solution would be to find efficient ways

一个很有前景的解决方式 也许是想办法高效地

to convert solar into chemical energy.

把太阳能转换成化学能。

This is already happening in labs,

这已经正在实验室里发生了，

but the efficiency is still too low to allow it to reach the market.

但效率仍然太低，远不能满足市场需求。

To find novel solutions, we'll need lots of creativity,

要找到更新颖的解决方式， 我们将需要很多创新，

innovation,

革新，

and powerful incentives.

和强大的激励政策。

The transition towards all-renewable energies is a complex problem

向全部可再生资源转移 是一个复杂的问题，

involving technology, economics, and politics.

它涉及到技术，经济和政治。

Priorities on how to tackle this challenge depend on the specific assumptions

应对这一挑战的优先次序取决于

we have to make when trying to solve such a multifaceted problem.

我们在试图解决这一多面问题时 必须做出的具体假设。

But there's ample reason to be optimistic that we'll get there.

可是诸多理由让我们乐观地 相信我们可以做到。

Top scientific minds around the world are working on these problems

世界顶级科学家们正在寻找 解决这些问题的方式，

and making breakthroughs all the time.

而且一直在取得突破。

And many governments and businesses are investing in technologies

许多政府和企业也正在投资技术，

that harness the energy all around us.

为我们创造源源不断的能量。