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How solar energy got so cheap, and why it's not everywhere (yet) - YouTube
Channel: DW Planet A
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It's astonishing, but clean energy from
the sun, solar energy, has become the
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cheapest way to generate electricity.
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It's even cheaper than coal.
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And yet it produces only three percent of
the world’s electricity.
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Why aren't we using way, way more of it?
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How did it get so cheap?
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And what does all this have to
do with...
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ducks?!
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Let's find out.
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First, let's take a look at how much the
price for solar has fallen.
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"I started this job as an analyst for solar
in 2005 and then I thought solar was
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ridiculously expensive."
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Jenny Chase is the head solar analyst
at research firm BloombergNEF.
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"You'd pay about 4$ a watt for
a solar panel.
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And today, you'd pay about 20 cents for
that same watt."
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And that is just the last fifteen years.
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If you look further back, the price drop
is even more impressive.
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How did this happen?
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"It's been a long story – but it's
unbelievable!"
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Gregory Nemet has written a book about this.
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"No one country did it. It was an exchange
of one country building on another.
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One: the US created the technology."
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The modern-day solar cell made from silicon
was invented in the US in 1954.
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Back then it mainly got used in the space
industry and was still super expensive.
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But as the technology progressed, prices
started to fall.
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"Two: Germany created a market."
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In 2000, Germany passed a law to boost
renewable energy development.
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This was big because it put a fixed price
on energy generated from sources like
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wind or solar.
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That gave people and companies a reason to
set up solar panels.
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And for them to do that, someone needed to
build these solar panels.
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Three: China made it cheap.
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Once the German law had come into force,
China really started to pump out
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those solar cells.
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"So basically it built the whole industry
for this on a scale that the West really
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didn't keep up with."
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"China was almost a non-existent player
20 years ago. And today they're
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the biggest producer of solar panels, about
70 percent of the world's production."
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So this is how we ended up
where we are now – with clean energy
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that also makes business sense.
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But if solar is so great, why don't we
rely on it much, much more and just switch
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off all these dirty power plants?
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Well, solar has always had this
one big problem.
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It only really works when the
sun is shining.
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When it's cloudy or – even worse – dark,
even the best solar cells
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are pretty useless.
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And that's a real shame because that's
when we'd need them the most.
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Let's take a look at how we use energy.
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In the morning, when most people get up
and get ready, we need energy.
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The so-called duck curve charts our demand
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for power from non-renewable sources
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like coal and gas throughout the day –
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first, in places without much solar.
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After the morning spike,
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it stays pretty level.
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When people come home in the evening,
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it goes up again and then drops at night.
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At this point, you might get an idea why
they call it the duck curve.
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Because it kind of looks like a duck.
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Anyway, in places with lots of solar,
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like California, this curve changes.
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The mornings are pretty much the same.
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Then the sun rises and solar energy
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production kicks in.
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This lets demand for non-renewable energy drop.
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Until the sun sets, that is.
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That is when conventional demand shoots up again,
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way steeper than in the first curve.
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Two problems with this.
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One: traditional power plants suck at
ramping up this quickly.
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That means you have to keep them running
at a certain output all day, even though
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there's lots of solar.
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And that means…
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"…you can end up with actually
more power produced in the middle
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of the day than is used."
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And that leads to the second problem.
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There are limits to how much energy you
can put into the grid.
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Too much solar could overpower it, so it
needs to be thrown away.
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This has always made it super difficult to
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add lots of solar to power systems.
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But guess what,
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there is now a solution to this.
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And chances are you have part of it in
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front of you right now, a lithium-ion battery.
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"We're just taking the same construction,
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stringing together many, many of those
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cells and making battery packs
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that we can use for cars.
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And then we can also scale that up to use
for stationary power to go next to wind
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parks or solar farms."
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"What's been quite good
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over the last few years is that
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batteries have got a lot cheaper as well.
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And we're now seeing solar projects built
with a couple of hours of storage in the
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battery so that they could shift some
generation from the middle of the day to
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the evening – where there's often a peak
in electricity demand."
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In the US, for example, the state of New Mexico just
decided to shut down a coal plant – and
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instead build new solar farms that store
large amounts of the energy they
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produce in batteries.
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Lithium-ion batteries have become a lot
better and a lot cheaper than expected in
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the last few years.
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They're now a viable option for storing
and shifting at least a few hours' worth
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of solar energy as needed.
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So, the storage problem that solar always
had is actually not that much of
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a problem anymore.
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Sometimes, though, we might
want longer-term storage.
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In places without much
sunshine, for example.
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And that's why companies are
offering other solutions.
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Let's just run through a few.
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Another type of battery, called a flow battery,
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separates the charge outside a cell.
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That has two advantages: It can store more
energy – and for longer.
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The problem is: they're
still relatively expensive.
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Then there's pumped hydro storage, which
is already used quite a bit.
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You need two lakes and one of them needs
to be on a hill.
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During the day, you use solar energy to
pump water from the lower lake up to
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the higher lake.
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When you need energy at night, you can
just let it run down through a turbine.
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But for that you need to find lakes and,
well, a hill.
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Another solution using gravity comes from
a Swiss company.
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It's working on a tower that raises
building blocks with solar energy, and
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then releases the energy by
lowering them again.
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But for this too, you need space.
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And there's also the option of using solar
to produce hydrogen.
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And with that hydrogen you could then do a
number of things, like fuel cars or
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even make steel.
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But the whole process is
still pretty costly.
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"I think that the storage will mostly be
lithium-ion with some hydrogen and maybe a
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few other options."
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"There are alternatives.
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It's just that lithium-ion batteries are
becoming so flexible and so inexpensive that
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it'll be hard for these
alternatives to compete.
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But they do have other attributes, like
they hold a charge longer, which could
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turn out to play a pretty important role
in some applications."
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So solar has become cheap and has pretty much
fixed its biggest problem.
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So what's next?
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"It's going to be big.
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It's going to be everywhere.
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We forecast that even with no further
policy, solar would supply about
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23 percent of global electricity by 2050.
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I personally think it's going to be much
higher than that."
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"I would not be surprised if by 2030,
we're talking about solar doing
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a large part of the world's electricity supply."
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Solar has come a long, long way.
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But now that the technology is in place,
it really looks like it's time to shine.
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Now we'd like to hear from you!
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What are your thoughts on solar energy?
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Let us know in the comments and hit subscribe
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