We learn aboutconservation of energy in school.
How you can take potential energy,
like the energy in the chemicals in this battery,
and you can then just convertit to electrical energy.
And then convert that to whatever you can find a use for.
A battery is just a storeof potential energy.
And that potential energy could be chemical, or it could be gravitational.
This lake in this rainy bit of Wales is part
of the largest battery in Britain.
And it’s rechargeable.
Welcome to Dinorwig Power Station,
otherwise known as Electric Mountain.
– What we have is a large reservoir at the top of the mountain
a large reservoir at the bottom, and
between the two, a power station,
which converts that potential energy into electricity.
The power station itself is located inside that mountain in deep caverns.
We release that potential energythrough the station.
It drives a turbine that spins around at synchronous speeds,
connected to the grid. It drives a generator,
converting that into electricity.
We then export thatonto the National Grid.
And then at nighttime, we justreverse the whole process.
The turbine turns into a pump.The generator becomes a motor.
And we push that water back up the hill into the reservoir at Marchlyn Mawr,at the top of the mountain.
The operating principle here is that the generation that the station is able to do during the daytime
helps the nation meet those peaksof electricity demand.
And overnight, it’s able to pump the water
back when prices are lower.
In electrical terms, we havearound nine gigawatt-hours
of storage at the top of the mountain.
And in fact over the course of a day, the water passing through the station is broadly equivalent
to the total householdconsumption of water in the UK.
At full load, we can be meeting
the demand of around about two million homes.
– This sounds like a really simple idea,
but when there’s this much energy involved,
the design challenges are ridiculous.
If you’ve ever lived in a house where you turn off a water tap
and the the pipes go clunk,
then you know about water hammer.
Water isn’t compressible,
so closing a tap means that
all the water that is under presure and rushing down the pipe suddenly has nowhere to go.
So if the pipes in your house aren’t secured properly,
the crash and rebound of all that water
can make the plumbing move and make noise.
If that can happen withjust a tap in a house,
imagine what could happenwhen one of the valves here closes.
At full capacity,
there is somewhere around a swimming pool every second
rushing through the turbines down there.
When that valve closes, allthat water heading down here suddenly has nowhere to go.
The pressure would doenormous amounts of damage.
It will break everythingapartif it wasn’t for one extra bit of plumbing.
A shaft hundreds of metres deep that acts as a pressure release.
We can’t see anything, on the surface or from down here, sadly,
it all happensdeep within the mountain.
But every time those valves move,
that surge pipe is whatstops the whole system from tearing itself apart.
This station is not somequirky old curiosity.
– Dinorwig Power Station is one of the largest
– Dinorwig Power Station is one of the largest power stations of its type in the world,
and it’s also one of thefastest-acting power stations.
So as well as being able to take advantage
of the peaks and troughs in the electricity market,
it was essentially built,
primarily,with the intent to provide very fast response onto the system
in order to help the National Grid balance supply and demand instantaneously on a second-by-second basis.
so it has the capacity to be able to go from zero up to its full capacity,
maybe 2,000 megawatts within ten to thirty seconds.
When people talk about pumped storage,
they tend to associate it a lot with TV pickups,
and National Grid, in analysing that risk,
study the TV schedules and plan ahead and put Dinorwig on standby,
if you like to ,to be able to meet those pickups.
Going back to the 80s and the 90s,
everyone would be sittingaround
the same TV channels with a limited choice, then.
All the ingredients you need for a sort of collective putting-on the kettle and opening of the fridge,
The pickups could be pretty significant.
But since then,
people are streaming on YouTube, on Netflix, all the different plethora of channels that we have
so that has changed that that sort of coincidenceof viewing on one channel.
The current environment that we’re in,
We have a significant amount of renewable technology on the system,
which provides a level of unpredictability day to day.
And actually, the importance of storage now is that we can use it
to help develop the amount of renewables we have
and allow us to fill in those gaps
when the winds not blowing and the sun is not shining
So having storage is such an important component of the modern grid system.
-thank you very much to all the team at Engie who made this visit possible
Pull down the description for more about them, and more about Electric Mountain.
A battery is just… a store!…of potential energy.