Name: ゼロエミッション電気にどれだけ近づいているのか？ (How Close Are We to Zero-Emissions Electricity?)
Uploaded: 2021-01-14T09:58:36.000Z
Duration: 10 min 31 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

We’ve all heard the statements and stats about the ominous timeline our planet is on.

To avoid the worst effects of climate change––from natural disasters to mass extinction––we

know that we need to reduce our greenhouse gas emissions. And fast.

And when we stop literally lighting things on fire to power our world, we can build something

that looks more like this. When you plug in, you’re pulling from a resilient local network

of abundant and affordable clean energy that keeps the sky blue, the storms at bay and

the birds, well… alive. So, how close are we to a zero-emissions grid?

Greenhouse gas emissions primarily come from electricity, transportation, and industry.

But in a zero-emissions future, this chart actually looks more like this. Because in

post-carbon world, almost everything relies on the electrical grid.

This means we’ll need a way bigger grid than we have today –– maybe as much double

the 4100 terawatt hours the U.S. currently uses per year. Right now that’s served up

through a high-voltage power system that draws primarily from centralized coal, nuclear,

and natural gas plants. Three main grids then deliver power by the minute to the eastern

half, western half, and the Texas… half... of the country, through local distribution networks.

We use almost no oil in the power sector to generate electricity, which is a good thing.

In 2017, we were 28% cleaner than we were back in 2005.

Two thirds of our power still comes from coal and natural gas, so we have a lot of work to do.

So what is that work, exactly? Well, electrical engineers see the life cycle of energy in

three main phases: generation––making it, transmission––moving it, and distribution––metering

it out. And to build a zero-emissions grid, each of these stages has to be clean and efficient.

If you look at how clean we are, nuclear makes up about 20%, Hydro is around 7.5% or so, and

then wind and solar together are getting close to around 8% and

then very small amounts of geothermal and some other renewable technologies.

So, how can we bump those numbers up? The fact is, most renewable sources are highly

variable. And finding a way to store that sunshine for a rainy day is challenge #1.

Often storage seems as the Holy Grail to allow us reaching a low-carbon society. Solar PV

and wind turbines are intermittent energy resources; if we need to have energy available

Today, the most common and widely used technology to store energy is pump storage, huge dams

with large lakes at the top and when we need

the energy we just open the dam and water is running down and generating hydro-electricity.

Compressed air is another viable solution for underground storage, and then, of course,

there are batteries, which are becoming cheaper and more widely available by the day.

With batteries, typically you just have a few hours of storage. We're going to need

longer periods of storage, not on the order of hours but on the order of weeks.

The problem is, pumped hydro storage, while powerful, has already been developed in most

of the places it can be. It has a huge ecological footprint and until materials scientists crack the immortal battery––and

don’t worry, we’ll let you know–– renewables are just too flaky to rely on entirely,

Nuclear power has been a very reliable source of zero emission power in the U.S. People

like Bill Gates and some other groups are helping to provide support for development

of advanced and small-module reactors. These are safer, cleaner, generate less waste than

the generation of nuclear reactors that we have right now.

What we call carbon capture and storage that we install on fossil fuels power plants —what it can

do is capture the CO2 before it reaches the air and you put it back to the ground. This

technology is not yet mature, it's very expensive. But this is definitely one of the

tools and one of the technologies that we would need to develop.

Of course, if we could just crack nuclear fusion, that would be another story. And maybe we will.

But once we’ve generated all the clean energy we need, our next challenge is to transmit

it. This is challenge #2, and as it turns out, it’s one of the biggest.

There are some areas that are just more geographically endowed with good renewable resources.

Places like Washington state create more hydropower

than they actually use so they have a high voltage direct current line from Oregon down

to the suburbs of Los Angeles that delivers that clean energy to Southern California.

Unfortunately, large infrastructure projects like this are a challenge to move forward,

because let’s face it: no one wants a power line running through their view––and building

We need to bite the bullet. We're going to probably need tens or hundreds of large power

lines constructed for this power grid of the future.

And putting up with some black lines of sky seems like a fair price to keep the whole

But, even the most efficient power lines still lose some heat through transport. And that brings

us to the final piece of the puzzle: distribution. Once the power gets where it’s going, it

has to get metered out to industrial, commercial, and residential consumers. And we’re working

hard to give many of these ancient systems a digital facelift. By learning about people’s

energy consumption habits, a so called ‘smart grid’ can actually adjust prices to keep

Energy efficiency should be promoted first. Any megawatt which is not consumed is a win-win here.

There are millions of smart meters that have been deployed throughout the US. They'd get

a signal, maybe perhaps through their thermostat or their smart device that would tell them

that prices are high right now and that they might want to hold off on doing the laundry

or running the dishwasher during the peak time of day.

But what if that kind of communication went both ways? Generating and storing power locally,

like using rooftop solar panels or electric car batteries, eliminates the need for transmission

entirely. And this is a concept known as distributed generation, or a ‘microgrid.’

Instead of pulling a set amount of power from a distant main source, microgrids allow custom

power delivery from a suite of sources as close as your own neighborhood, and this turns

its participants into “prosumers,” because they are both producing and consuming electricity.

A device called a microgrid controller acts like a dj, dropping live beats to match the

energy of the crowd… or the energy consumption of a neighborhood. And this allows prosumers

to buy and sell cleaner electricity to and from their own individual power systems, saving

A microgrid manager or controller knows what the weather forecast is for the day, it knows how much solar you're

going to be able to produce, how much storage is available and knows when to have the natural

gas backup kick in. It knows what the power prices might be and when it can be selling

power into the grid or buying power for very cheaply from the main grid.

It can be optimized based on producing the fewest amount of greenhouse

Some countries are getting close to a zero-emissions grid. Iceland has so much hydropower that

Tackling climate change and reducing emission is a global challenge. So even if California

and Germany and all Europe becomes zero carbon it doesn't matter if the whole world won't

unify and act together to achieve this goal because a molecule of carbon does not care

if it was emitted in China or in Israel, it will impact the climate the same.

And that’s not even counting the billion people in developing nations who are expected

to become energy consumers in the next century.

The truth is, energy is different everywhere. But what all of us need is a healthy mix of renewable and

zero-emission sources; next generation storage solutions, more transmission lines and less

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ゼロエミッション電気にどれだけ近づいているのか？ (How Close Are We to Zero-Emissions Electricity?)

eliminate

matter

tackle

consumption