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.
So let’s start with generation.
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
all the time, they cannot supply it.
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,
without some additional help.
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
them underground is a spendy endeavor.
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
sky blue.
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
up with supply and demand.
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
time, dollars, and carbon.
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
gases.
Some countries are getting close to a zero-emissions grid. Iceland has so much hydropower that
it sustains their entire nation.
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
need for transmission at all––namely, a smart distribution system that shows us
exactly when and how all this energy is moving around, helping us save megawatts and dollars.
Experts agree that we must make big strides before 2030, and reach complete carbon neutrality
by 2050, to avoid the 1.5º threshold that spells climate chaos.
Currently we are headed to 3.2 degrees celsius warming. If we want 1.5 degrees celcius, we need to do five times more.
We kids shouldn’t have to do this. I wish the adults would take their responsibility
but since no one’s doing anything, we have to.
So… how close are we to a zero-emissions grid?
We are not so close. Actually, we are not close at all, but we definitely have means
and tools to accelerate this transition.
We're still emitting somewhere north of 50 gigatons of greenhouse gases every year. We
need to stabilize that.
We can get there but we need to do it faster, we must be more ambitious, put more effort
and think in the box, out of the box, underneath the box and all the way that we can promote
this really, really important goal of low carbon society.
Brains, exoplanets, dark matter, miracle cures, giant wooly mammoths?!
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