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Kind: captions
Language: en

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For a few hours in May 2016, for the first
time in more than a century,

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Britain was burning zero coal to generate
electricity.

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None at all.

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All the coal-fired power plants
were turned off.

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And this here is one of the reasons why.

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Welcome to the Griffin Wind Farm in Scotland.

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68 turbines, more than 150 megawatts of capacity.

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And the turbines rotate and trim the blades
to track the wind in real time.

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At full output, this can power entire cities
just from the wind.

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But as the world moves to renewable energy,

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we’ve got a little bit of a problem.

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Because coal, oil, gas, and nuclear stations
are basically just giant boilers.

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They take water, they heat it up,
that turns to steam,

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the steam gets forced through a massive turbine
which rotates and generates power.

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When I say turbine, I don’t mean like the
blades here,

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I mean hundreds of tonnes of steel rotating
thousands of times a minute.

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And all those turbines, all around the grid,

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rotate in sync with each other.

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After gearing, they all move at
50 cycles a second.

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60 in America.

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All perfectly in time: one slows down, they
all slow down.

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One speeds up, they all speed up.

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And that is what stops your lights
from constantly flickering.

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Because electricity supply has to always match
demand, pretty much exactly.

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There isn't a battery in the world big enough
to store power on a national scale.

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So if a power station suddenly falls off the
grid for some reason,

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then where’s that supply going to come from?

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And the answer is the kinetic energy that’s
already in those turbines,

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in that spinning thousands of tonnes of steel
around the country.

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Homes and factories will literally suck the
kinetic energy out of that turbine

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to cover the gap, starting to slow it down.

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But that won’t cause a problem
for 60 seconds or so,

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and in that time the National Grid
Control Centre will, I don’t know,

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throw another nuclear rod on the barbie

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and up the power output from other stations.
They'll cover the demand.

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But, well, that relies on
having enough rotational mass,

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enough system inertia, as it’s called.

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And here, in this turbine?

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Well, you can see.

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There’s no hundreds of tonnes
of spinning steel,

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just some blades, a bit of metal,

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and some circuitry that feeds the power into
the grid at the right frequency.

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If the whole grid were running on
just wind and solar,

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there's no rotational mass.
There's no grid stability.

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The minute that supply and demand mismatch,
breakers would trip,

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and the whole thing would fall apart.

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Now there are some
possible solutions to this.

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Pumped hydro storage
has been around for a while,

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which is where you have two lakes
at different heights.

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When you’ve got too much power,
you pump water up,

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and when you’ve got not enough, you drop
it back down again through generators.

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But that takes seconds or minutes
to kick in.

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There’s also some experiments going on with
things like molten glass storage,

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compressed air storage, and flywheels,

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but they’re all experimental at the minute
and not particularly efficient.

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The actual solution may come from somewhere
a little unexpected.

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Because yes, wind is replacing coal and oil,

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but it’s also replacing petrol, the gasoline
that you put in your car.

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And as more and more and electric cars
get connected to the grid, well,

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you’ve got a load of quite large batteries
with computers.

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Your car could sell power
back to the grid in real-time,

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second by second, as it’s needed.

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Combine that with smart appliances and meters
that can watch the grid

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and work out when would be the best time to
turn on your air-conditioning and fridge is,

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and you have a grid that does
a lot of the balancing itself.

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Yes, we will probably always need a
turbine somewhere,

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some big spinning mass of steel to cover
the little glitches second to second,

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but the solution to balancing a power grid
is not what we thought it was 20 years ago.

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It’s not big, monolithic batteries.

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It’s millions of small ones
up and down the country.

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Thank you very much to all the team from SSE

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who have helped get me, and my team,
up on top of this wind turbine.

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I am incredibly grateful.

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They have gone above and beyond to help out,
so please,

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have a look at the links in the description
for more about them,

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and about the Griffin Wind Farm.

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