(exciting music)
This time, we reveal how cities
are kept supplied with electricity.
Power goes out here, there's no show. (chuckles)
From the world's most advanced
solar power station...
For me this is the chance of a lifetime
to really make a difference.
It is the first of its kind.
We fly with the unsung heroes
who risk everything to keep power flowing.
I am an experienced helicopter pilot
and I think, why am I doing this?
This is unbelievable.
And uncover how tunnels
deep beneath Britain's capital
will keep the city alive.
What we're doing here is rewiring the whole of London.
(dramatic music)
Half the world's population
live in urban areas,
and the number is rising every second.
Each day is a race against time
to house, feed, water, and move
more than 3.5 billion people.
It's an impossible daily challenge.
The slightest glitch can bring a city to its knees,
and every 24 hours, it has to be done all over again.
This is the story of how cities work.
(light tense music)
Las Vegas.
This neon oasis in the heart of the Nevada desert
needs over 5,000 megawatts of electricity every day
to power the hotels, casinos, and light shows
that have made it famous.
The most impressive show in town
can be found on Freemont Street.
(exciting rock music)
Towering 30 meters above a pedestrian mall
is one of the largest LED screens in the world.
It spans four city blocks in Downtown Vegas,
and is one of the most spectacular shows in the city.
People are always attracted to bright lights.
Whether it's here, Times Square, the Strip,
people love going where the lights are.
A staggering 12.5 million individual
LED lights are carefully synchronized
to create a unique visual extravaganza.
(energetic rock music)
Every night, Freemont Street consumes enough energy
to power nearly 300 homes.
It doesn't come cheap.
The annual electricity bill
is close to half a million dollars.
Well, the Freemont Street experience
uses a lot of power.
Just from all the lights and LEDs,
and from the canopy itself, from the casino lights,
to the stages, and even here in the control room.
I mean, if the power goes out here,
there's no show. (laughs)
Electricity powers the life support systems
that keep our cities running.
Lights,
trains,
communications,
even hospitals rely on this invisible force.
Without it, our cities stop working and lives are at risk.
(exciting music)
In New York, the system is near breaking point.
Every day, the city consumes more electricity
than the entire country of Greece,
and every kilowatt is piped here
along a network of high voltage power lines.
But some stretches are over 40 years old
and in need of urgent repair.
If they fail, the whole system can collapse.
7:30 a.m.
It's Vinny Cartier's job to keep the power flowing.
Vinny isn't an engineer.
He's a helicopter pilot.
A lot of people think we're crazy,
but I love the guys that I fly with,
and I love the mission, and I love the challenge.
(light music)
Vinny is part of an elite team
who risk their lives to maintain
the high voltage power lines from the air.
The network runs over miles of countryside,
much of it inaccessible to a road crew,
so while Vinny does the flying,
Ryan Hill is tasked with carrying out vital repairs.
We have 1200 miles of conductor
and over 5,000 structures in our system,
so it'd be tough to get that by foot,
so if you do it by air, you'll get it done pretty quick.
Many cities around the world
are forced to turn off high voltage lines
to carry out vital repairs,
but New York's need to keep affordable power flowing
all the time is so great that Vinny and Ryan
have to work with half a million volts
surging through the cables.
One wrong move could spell disaster for them both.
You would think you would shut the power off
to maintain the lines, but it's very critical
to keep that energy flowing to the customer.
Each power line consists of multiple wires
that must be kept apart.
If two lines touch, the whole system could trip
and cause a blackout in the city.
Simple metal spacer bars separate the lines,
but some are old and could fail at any time.
Ryan and Vinny must replace them before it's too late.
These have probably been up there since the '70s.
If we let the spacers deteriorate and not maintain them
they'll eventually break off,
and then you'll have all the lines smacking each other,
and you wanna avoid that.
This is what's up there now.
Existing spacer.
And you'll have the two conductors running through here,
and as you see, this one's pretty old,
but they need to be replaced now,
so we're gonna go up there with the helicopter,
we're gonna install the new ones here,
so we're gonna take these four bolts off the old one,
we're gonna add these on it, put the new one on,
these'll be up there for a good 50 years now.
To get the job done,
the team needs perfect weather conditions.
We need calm winds, no gusts,
or else the machine will not be happy.
All right, so the weather's looking good right now,
but after about 10 o'clock it's gonna pick up a little bit
so we really need to get this done now,
so let's go do it.
With the wind forecast to pick up
in two hours time, the clock is ticking.
But before Vinny and Ryan can get to work,
they need to modify the helicopter.
This platform allows Ryan to get within touching distance
of the power line,
but hanging out so far on one side
will destabilize the helicopter,
so the crew add counter weights
to keep it precisely balanced.
You feel comfortable sitting on it?
Absolutely.
As long as you're flying it.
With their lives on the line,
there's no room for error.
Vinny has last minute checks to do.
Looking at everything three times.
Looking at every harness, every latch,
every bolt, every weld.
All the components on the helicopter,
no matter how many times you do it,
you go up on your flight, you can't get complacent,
and you always need to be thinking,
what have I thought of
or what haven't I not thought of,
and make sure everything is where it should be
and everything's in place.
There's no second chances.
Helicopter ready, it's time to get suited up.
These aren't your regular flight suits.
To prevent electrocution, Ryan and Vinny
must wear protective overalls that have steel thread
woven into the fabric.
These suits here, part Nomax and part steel.
They have little steel strands woven into them.
In theory, this thread conducts electricity
more efficiently than flesh and bone,
so when Ryan touches the cable,
power flows around him, not through him.
(intense music)
This is definitely not a beginner's job.
There have been inexperienced guys
that have wanted this job,
and I don't think they understand the risks of it.
I am an experienced helicopter pilot,
and I question myself some days
thinking, why am I doing this?
This is unbelievable.
(intense music continues)
All right, we got a timer ticking.
All gauges in the green, lights are all out.
All right, let's lift. You good?
Nice and clear on the tail.
(dramatic music)
How you doing out there, you all set?
Yes, sir.
How do you feel buddy? Good.
Nice and loose, come on.
It's now 9:00 a.m.
Getting to the job site will take 45 minutes.
Ryan and Vinny will have to work fast
to complete the spacer change
before the weather closes in.
If the wind begins to gust,
it will make an already dangerous task deadly.
Teamwork is crucial.
Biggest key up there is communication.
Constantly talking to Vinny.
Any movement that I make in that aircraft,
Vinny will feel, and it'll affect the helicopter.
There's very small margin for error.
We work very closely together.
I need to be able to understand what he's doing.
And if I'm not aware beforehand, it becomes a surprise,
and surprises aren't good.
All right, you all set?
Yes, sir. Bring her in.
Before he can get started,
Ryan must electrically bond the helicopter
to the power line using a special wand
known as a hot stick.
Bonding on is one of the most dangerous stages
of the flight.
It's a rush, you know?
When you first realize what you're about to do,
you're about to bond onto 500,000 volts.
(electricity zapping)
You see the arc to the wand,
that makes me part of the circuit.
All right, we are bonded.
You don't feel it.
Once in a while when you're working on a wire,
you might get a little nip in the hand,
but it's not uncomfortable.
Electricity's going around you,
around the helicopter.
It's a rush.
Once attached,
electricity flows around the helicopter,
keeping Vinny and Ryan safe.
I trust Vinny with my life up there 100%.
Lift me a little bit.
Coming in, coming in.
See what this bad boy's got.
Ryan now faces a race against time.
(intense music)
With strong winds forecast, every moment spent
connected to the 500,000 volt cables
spells danger for the crew.
Ryan must work fast to replace the aging spacer bar
holding the lines apart before the weather
grounds the chopper.
Gonna zip this one down.
I'll get you a little bit higher.
I'm gonna give it a little yank.
Yup, fine. I'm ready for it.
While Ryan gets to work,
it's down to pilot Vinny to keep the helicopter
in a stable hover, centimeters from the live power line.
Wait, I'm gonna get you in the air a little more.
There you go.
Watch it above your head.
Yup.
One thing you really need to do
is keep calm and relaxed and on top of your game.
An unexpected gust of wind
could be devastating.
Wind is everything with this helicopter.
Definitely not any gusts, unexpected gusts
will make you climb or descend.
If the chopper touches anything else,
a tree or another power line,
Vinny and Ryan could be instantly electrocuted.
It takes every ounce of concentration to complete the move.
Hovering the helicopter next to the lines
is definitely some of the most challenging flying
you can do.
The inputs on the controls are thoughts.
There's not actual pressures, and definitely no movements.
You wanna go higher, just think it,
and you're starting to go higher.
With this helicopter, it's extremely responsive,
and it's very powerful, very maneuverable.
The new spacer doesn't quite fit,
and Ryan doesn't have the tools he needs to adjust it.
Yeah, we'll have to break off, man.
All right.
To keep weight down,
Ryan only has the bare essentials on board.
A hammer isn't part of his toolkit.
You wanna grab a hammer?
Hell, we'll get one.
The ground support crew has one,
but it will take too long for Vinny
to get permission to land.
To retrieve the hammer, he must carefully hover
a few feet above the ground
while it's transferred on board.
(electricity zapping)
See what we can do here.
I'm gonna give it some whacks, all right?
All right, I understand you're whacking it.
With the right tools, the job is soon done,
just as the wind starts to build.
Ready?
Take me away.
All right, taking you away.
Ryan and Vinny's daily battle
on the front line is crucial.
Without them, the system would break down.
Let's get out of here, pal.
And behind them, an army is at work
generating the power that flows down the line.
(exciting music)
Around the world, approximately two-thirds
of all electricity is produced by burning fossil fuels.
But that's beginning to change.
In the future, up to a fifth of global energy requirements
could be met by environmentally-friendly biomass.
Organic matter, such as wood or straw,
that is used as a fuel.
40 kilometers from London, Tilbury Power Station
used to burn coal, but in 2011 it was converted
to burn wooden pellets made from compacted sawdust.
It's now one of the largest biomass power stations
in the world, and a vital piece
of London's power infrastructure.
Dave Dyson is the station's engineering manager.
Tilbury produces about 800 megawatts
of renewable power.
That's a significant part of what London requires,
about enough to support 1.5 million homes.
It's 8:00 a.m.,
and Tilbury Power Station has a problem.
One of its three huge boilers has sprung a leak.
Every minute the boiler is out of action
threatens London's power supply.
Dave is under pressure to fix the tiny leak,
and get the massive furnace back on line.
The boilers, as you can see, are huge.
They're 15 stories high, 20 meters by 20 meters.
They turn 1,000 tons of water into steam every hour,
and the whole thing's a huge fireball.
To generate electricity,
pellets are burned in the middle of the boiler.
The heat produced turns water in the boiler tubes
into high pressure steam.
This steam spins a turbine that rotates a rod
covered with magnets.
The magnets are surrounded by a spool of copper wire,
and as it rotates, a magnetic field is created.
This causes electrons to flow, producing electricity.
A broken boiler means no steam and no electricity.
The engineering team has found the source of the leak,
now they need to repair it.
An experienced boiler engineer knows the sound
of a boiler, just by walking down the boiler
he can tell if there's a leak and where it is.
He knows the sound of it, he walks around it every day,
and he can detect a leak, determine where it is
just by the sound.
The boilers are the heart of the power station.
When they're working, temperatures inside
reach 1100 degrees.
A tough environment for the metal pipe.
There's approximately 240 miles of pipe
within the boiler, so it's not surprising
that we get the odd failure now and again.
(tool whirring)
The pressure is on Martin and his team
to cut out the burst section of pipe
and insert a new piece.
The most common kind of failure
in conventional power stations like Tilbury,
is a boiler tube failure.
These tubes operate in very severe hostile conditions.
So if they're not in the best condition,
they won't survive.
We're constantly trying to engineer
new ways of preventing damage,
of monitoring the boiler conditions
in a more effective way, to minimize the failures,
but with 240 miles, it's still pretty difficult
to do that every day of the week, every week of the year.
400 kilometers of piping
to keep in perfect working order
is an extraordinary task.
Until this section of it is fixed,
Tilbury is unable to deliver its full quota
of electricity to London.
The power station supplies London with electricity
via the National Grid, a network of power lines
stretching right across the country.
The grid is designed to cope with an occasional
burst boiler pipe, but if other stations
have a problem at the same time,
London could face a blackout.
It's vital Tilbury's other two generators keep working,
and for that, they need fuel.
These are the pellets that we burn in the power station.
This kilogram of pellets here
produces about two kilowatt hours of electricity.
That's enough to provide 90 cups of tea,
charge your mobile phone for the best part of a year,
or to power the average sized TV for about 16 hours.
Scale this up to meet the needs
of almost 1.5 million homes,
and Tilbury has to burn a staggering amount of pellets.
Ross Philips is part of the team responsible
for keeping supplies flowing.
Trying to explain to people the appetite
Tilbury has for wood pellets is difficult.
The sheer scale, the number of pellets we use
is mind boggling.
Ross depends on shipments
from all over the world.
In the long term, it may be difficult to source
the vast amounts of fuel Tilbury needs
from sustainable sources.
The general size of ship that we get in Tilbury
holds anywhere between 20,000 and 45,000 tons.
And that all lasts Tilbury no more than four, five days.
This vessel is en route
from Georgia in the USA.
It's carrying 6,200 tons of pellets,
enough to supply Tilbury for just 16 hours.
We currently burn around 450 tons of biomass every hour
when we're generating.
Over a year, that's enough to fill
Wembley Stadium four times over.
To unload, pellets are simply sucked out of the hold
by a machine that operates
just like a giant vacuum cleaner.
It's a never-ending cycle.
The problem is that you can't store pellets outside.
If they get wet, they become unusable.
Therefore, pellets are moved straight from the ship
into the station.
This supply and demand system
has a major drawback.
If the flow of pellets is interrupted,
the station could run out of fuel in just six hours,
creating a hole in the National Grid
that other stations would be forced to fill.
It's Marcus Nikola's job to monitor the pellets
as they travel along almost a kilometer of conveyor belts
into the power station.
The wood pellets are as dry as a tinderbox.
Fire is an ever-present danger.
There is a potential fire risk
from all the moving parts from our bearings and our rollers,
so everything has to be monitored
to ensure that there is no fire risk.
At Marcus' disposal are 76 CCTV cameras,
smoke detectors, and infrared cameras.
But he isn't just reliant on technology.
Basically, we always have an outside man
because as you walk around, you hear things,
you can see things.
We have all this state of the art technology,
but there's no substitute for a person out
walking the actual line.
And right now,
Marcus is in need of his outside man.
A conveyor belt has stopped, halting the flow
of pellets into the power station.
Conveyor 18, we've got a Hewitt trip.
Just investigate for me, over.
So we've had one of our conveyors go down,
conveyor 18 has had a trip on it.
That means now we've got no path at all
to the bunker house, so right now we can't move
any pellets from the ship to the station.
Ross must get the conveyor working quickly.
Without it, the power station will run out of pellets
in just four hours.
If we can't generate, less power will be available
for London to use.
The network of conveyor belts
contains several thousand moving parts,
but Ross is quick to spot the problem.
It looks like there's been a pellet spillage.
I can't see any obvious obstructions.
There's any number of things that could cause
a spillage like this, a foreign object,
or a piece of tram coming off the boat
could cause a blockage, which could then cause a spillage.
John, I've reset the Hewitt trip here,
could you confirm that it's available now, please?
Yeah, 18 conveyor now available.
Sorted out.
Production resumes,
but hours into the afternoon shift,
Marcus Nicola calls on Ross for a second time.
Conveyor 18 is down again,
and the problem appears to be far more serious.
I found the problem on conveyor 18.
One of the return rollers is broken.
You can see a little bit of the debris here
on the ground.
And it's come loose, it's come detached
from the attachment on the side, here.
Until the broken roller is fixed,
Tilbury will have to rely on just a single conveyor belt.
As a result, this belt will probably be out of action
for a good four, five hours,
which means we're down to just the one belt now.
But with that one belt we can keep going.
It does mean we're slightly more vulnerable.
As long as we don't get another problem with the other belt,
we're all right for now.
But it's cutting it close.
Despite only one conveyor belt working,
fuel supply resumes.
Inside the broken boiler, engineers have removed
the burst section of pipe.
It was probably original tubing
from when the boiler was built.
It's overheated quite quickly
and has just become too soft to take the pressure,
and it's burst, and you can see
with the effect we've got here.
Before they can repair the boiler,
Martin needs to inspect the remaining pipe.
This is a pipe camera.
It lets me look up small ball pipework.
Making sure that we've cleared all the damage.
I can see that that end's clear.
So is that, so we've cleared all the damage
from the tube.
Its replacement is seven millimeters thick,
strong enough to withstand the ferocious heat
inside the boiler.
You could make them thicker,
and make them stronger in some respects,
but that would simply make the heat transfer poorer
and possibly introduce fatigue failures
because they'd flex less easily.
It's finding the right size of material,
the right material itself to operate
in the conditions in which it's been asked to.
The weld has to be perfect.
The slightest fault will quickly lead to another leak.
Hi Ty, it's Martin,
just to let you know we finished welding in the boiler,
give us an hour to clear it down and it's all yours.
Job done.
But it will take another four hours
for the boiler to produce enough steam
to spin the generators and produce electricity.
Biofuel powering London is just
one technological breakthrough in the battle
to keep electricity flowing.
Electronic billboards, data storage,
even mobile phones are all pushing up demand
for electricity in our cities.
Now, an army of engineers is trying to wean these cities
off electricity produced from fossil fuels.
They are looking for new ways to generate clean power
using unlimited natural resources.
In parts of the world with clear skies,
that means power from the sun.
(intense music)
In the Nevada desert, technical director Brian Painter
and his team face the biggest challenge of their careers.
It's technology that was developed
by literally rocket scientists in the middle '80s
and this is the first commercial venture
for this technology.
They are building a groundbreaking
solar thermal power plant,
and it must be finished in less than six months.
Crescent Dunes Solar Thermal Power Plant
doesn't use conventional solar panels.
Here, over 10,000 mirrors called heliostats
are being built around a 195 meter tower.
The heliostats will focus the sun's rays
onto a special receiver at the top of the tower.
This concentrated solar energy will be used
to create steam that will produce electricity.
When you're driving through the heliostat field
it's just like driving through a big mechanical forest.
It's steel, it's computer controlled systems,
and it's glass.
So far, just 1400 of the 10,000 heliostats
have been installed.
Eventually, they will cover
over five square kilometers of desert.
The project requires so many
that a temporary factory has been built onsite.
It churns out 80 heliostats per day,
thanks to manufacturing processes
lifted straight from an automotive plant.
Every one is designed for a specific spot
on the desert floor.
Getting them all to work together
creates a mammoth headache for Tim Connor.
We have to go through this initialization
and calibration for each individual heliostat,
all 10,348, before they can be operated
as a collector field.
Each heliostat consists of 35 mirrors
or facets, every one of which must be perfectly positioned
to focus the sun's rays on the top of the tower.
Each heliostat has a focal length,
and each individual facet is slightly curved
based on the distance it is from the tower
and the receiver.
What I'm doing here is running the heliostat
through the range of motion for the elevation,
and we take it from the plus 90 to the minus 10 position.
Some of the heliostats are more than
half a kilometer from the receiver.
What you see now is since the concentrated energy
from the single heliostat,
you can imagine the intensity, the thermal intensity
on a receiver with 10,348 heliostats
focused all at one time.
The amount of energy with all the heliostats
pointed at the receiver would melt aluminum
in a matter of seconds.
Once the sun's rays hit the target,
the precise position is recorded,
and the calibration is complete.
What happens once the sun's rays hit the top of the receiver
makes this power station unique.
The sun's energy is used to heat molten salt
to over 530 degrees Celsius.
The salt that we're using the system
is not your regular ordinary table salt.
It's only found in a couple places in the world,
and its value is in its density
and the ability to store energy.
Salt is heated by the focused power
of the sun.
It is then piped into a storage tank
where it retains heat for up to 10 hours.
When power is needed,
the molten salt is pumped to a generator
where it boils water, producing steam.
This steam spins a turbine, generating electricity.
As the salt cools, it is pumped back
to the top of the receiver to be heated again.
Right now we're standing in the middle
of the hot salt tank.
It's a very large tank, 140 feet diameter,
40 feet tall, it'll hold 70 million pounds of salt
that is 1050 degrees Fahrenheit.
The tank acts like a giant battery,
storing the sun's energy until needed.
Crucially for a power station fueled by the sun,
this means it can produce electricity
long after the sun has set,
and even when the sky is cloudy
it can generate electricity reliably,
day in and day out.
We can actually collect the energy during the day,
and then we can operate whenever we want.
So essentially electricity collection
and electricity generation are two separate processes,
so the utility here in Nevada
is looking first to generate reliable electricity
well into the evening hours, 12:00 noon to 12:00 midnight.
Today, a key piece
of the steam generating plant
is being lifted into place.
The drum weighs in at 95 tons,
making the lift a difficult and potentially dangerous task.
To withstand high pressure steam,
the drum is made of five centimeter thick steel plate.
If it falls, it will destroy the structure it sits on,
and set Brian and the team back by several months.
What's that?
Right now we're raking up a steam drum.
This is pretty well the last heavy lift
we have on the site.
We're gonna set it up on top of the steel structure
on top there.
We don't want anybody hurt.
We don't want any equipment damaged,
and so there's a lot goes into this lift.
A lot of planning and preparation,
to make this lift happen.
Installing the drum is an important milestone.
This vessel right here, it's the last part
of the process of making steam.
The steam travels through the piping from here
to the steam turbine.
Another piece of this complex jigsaw puzzle
is lowered safely into place,
bringing Crescent Dune Solar Thermal Facility
a step closer to producing the electricity
Las Vegas can't live without.
When the switch finally goes on
it will be a tremendous rush for everybody.
I mean, we've been building for years
to have this technology really take hold,
and to see the facility come together is great,
but once we turn that switch on,
it'll be fabulous.
When complete, the plant will provide
110 megawatts of power, enough for 75,000 homes.
It might not rival the 1.4 million homes
powered by London's biomass burner,
but in theory, this technology could supply
all the electricity Las Vegas needs.
When you're looking into the future,
cities like Las Vegas and Los Angeles
are gonna be utilizing a tremendous amount
of solar energy for their power needs,
and this project can help meet those future requirements.
(light music)
But not everywhere
gets as much sun as Las Vegas.
All over the world, new ways of generating power
are being developed using local resources.
In many places, that means wind power.
There are now 225,000 turbines
spinning in 79 countries,
and more are being built every year.
18 of them are at Middlemore Farm at Northumberland.
The turbines here will soon produce enough electricity
to power 27,000 homes.
It's a tiny number set against Tilbury's 1.4 million,
but by 2020, over 15% of London's electricity
could come from the wind.
We chose this site because it's windy,
and we'll make lots of energy out of it.
And it's also quite close to the grid
so we can export the electricity to it.
The power produced here
will be exported to the National Grid
that supplies London with electricity.
We started at the end of January
and we've got about 14 turbines up at the moment,
just building the 14th one,
and we expect to finish it in about two or three weeks.
To meet this deadline,
the construction team need calm weather,
and this can be hard to come by on a wind farm.
It's a paradox of the industry
that the places where you actually want to operate
the wind turbines, because they're windy,
then that gives you a problem in construction,
because when it's too windy we can't actually build.
The crane can't lift.
Each turbine arrives on site
in seven pieces.
The heaviest weighs 77 tons.
Lifting pieces this big 80 meters in the air
is a task that requires one of the largest cranes
in the UK.
But even it can't lift in windy conditions.
With so much at stake, site manager Dave Whittaker's
first job is to check the weather.
Well, looking at the forecast today,
we've got some very high winds coming.
It's forecast to get a lot worse,
so what we usually do is
go down to the crane and see what the crane reading is.
If the wind speed is too high on the crane
the team can't lift the turbine.
The final call falls to crane driver, Seamus Camidy.
If the wind catches that, it has a pendulum effect,
and it can either turn around or start swinging,
and if it starts swinging,
there's nothing gonna stop it, you know?
I'm getting 16 or 17 meters pushing into the crane
so it's not safe at the minute.
Okay, just safety reasons.
We'll just call it then, today.
Yeah.
It's a serious blow to the schedule.
Finishing in three weeks time will be impossible
if the bad weather continues.
Next morning, the wind has taken a break.
Dave and his team need to make up lost time.
This looks good, mate.
And weather for today,
let's just get it done.
The plan is to lift the second
of three tower sections, and stand it on the first.
If we get our perfect wind conditions in
we get enough preparation work done beforehand,
the actual lifting procedures,
we can erect the turbine in one day.
Conditions may not be perfect,
but they are good enough for the lift to go ahead.
(soft tense music)
Slowly, the 24-meter long section is lowered into place,
and bolted down from the inside.
The wind is beginning to pick up.
The team can't risk another lift.
With two sections complete,
the structure can be safely left for another day.
It's extremely windy today,
and it's above our legal limits and it's dangerous,
so we don't take any chances.
With further progress
dependent on good weather, the team's chances
of hitting their deadline diminish by the day.
When we have wind days it is really frustrating
because we're here to build a wind farm,
and due to the wind, we're set back a day with the lift,
and that puts pressure on the guys
so it does get really frustrating,
but that's part and parcel of building wind farms.
While wind stops play at Middlemore,
engineers at another new wind farm
are making the most of good weather.
Bradwell-on-Sea's 10 turbines
will generate enough power for up to 12,000 homes.
Today, turbine number nine is due to be completed.
Lifting this piece is technically difficult
and needs two cranes to work together.
The larger crane has to lift the 76 ton section
from horizontal to vertical,
and then raise it 28 meters in the air.
To prevent the bottom of the tower getting damaged,
the second, smaller crane,
has to lift the base of the tower
clear of the ground at the same time.
Once in place, the tower sections are under
massive side-on pressure from the wind.
They have to be joined together by 84 bolts,
each 3.5 centimeters thick.
We're just getting at the top section on.
Once that gets on, then it'll take the guys
maybe half an hour, 40 minutes,
to get the bolts in and stuff.
Next up is the nacelle.
This 69-ton capsule sits at the top of the turbine
and houses a generator and gearbox.
Just like at Middlemore, as engineers prepare to lift,
the wind begins to pick up.
Yeah well we started this morning,
we were here for eight o'clock like we were getting to be
two three meters per second
and at the minute there it was gone up
to maybe seven meters per second, eight meters per second.
Having put the third tower section on,
the team must lift the nacelle today.
Its weight will stabilize three sections of tower
and make it safe to leave overnight.
We have to get the nacelle on top of the third section,
otherwise your tower will start to oscillate
you know, if it's left and the wind speeds pick up.
The nacelle is the size of a bus.
If the wind swings it into the crane,
both will be destroyed.
The team daren't risk lifting the turbine blades.
That job will have to wait for the morning.
We've got the nacelle up as you can see yourself,
we've got it up this evening there.
The wind was starting to pick up, but we got it up.
(light uptempo music)
At a just completed turbine
on the other side of the farm,
project manager Adam Potter is in need of some wind.
And the final process for commissioning
is to actually see whether it generates electricity,
and the best way to do that is simply by turning it on.
The UK's newest wind turbine
slowly comes to life.
And now we can see that the turbine
is generating electricity,
the numbers are gradually increasing,
eventually it will reach over 2,000 kilowatts,
and that's enough to power 1200 homes.
Wind power looks set to play
an important role in securing London's supply of energy,
but it can't entirely replace the need
for electricity produced from fossil fuels.
You couldn't just have wind farms in isolation
because when there is no wind,
you need to have other sources of power.
The key to it is that when it is windy
then you're reducing the amount of power
that you need to generate from other sources,
such as fossil fuels.
Across the world, electricity use
will increase 85% by 2040.
Many of the networks that carry this power
into our cities are near breaking point.
Radical solutions are needed to keep the power flowing.
London's population is expected to increase
by one million in less than 10 years.
With more and more power flowing into the capital
from power stations all across the UK,
the National Grid faces the biggest challenge
of its 50 year history,
and to secure London's electricity supply,
engineers are battling to dig 32 kilometers
of tunnels beneath the capital and rewire the city.
Garreth Burden and Richard Spencer
are overseeing a crucial part of the project.
The increase in demand and the aging network
essentially means what we're doing here
is rewiring the whole of London.
(uptempo music)
The existing network
runs under the city's roads.
Digging it up and replacing old cables
would bring the city to a standstill.
The solution, build an underground electrical superhighway
to carry upgraded power lines into the heart of the city.
This is the most ambitious and significant project
that the National Grid's undertaken
probably since they built the original network.
The grand plan is to dig 32 kilometers
of tunnels, connecting substations across the city.
But beneath London lies an existing subterranean network
of vital infrastructure.
Tunnels water of deep, deep water tunnels,
you obviously have the London underground network,
you have some network rail tunnels
as well as other deep infrastructure,
such as cross rail.
It's like spaghetti junction for tunnels,
London, in some regards.
The miners can't afford to get it wrong.
Accidentally tunneling into a busy underground line
would be a major disaster.
Two teams of miners are working around the clock.
Each 12-hour shift begins with an underground journey
deep beneath the city.
(exciting music)
(brakes squealing)
We're currently 30 meters under the ground
where we're sitting right now.
We've journeyed for approximately 10 minutes
and we're 1500 meters in.
To dig this tunnel, engineers are using
100 meter long tunnel boring machine, or TBM,
nicknamed Evelyn.
At the front of the TBM,
a cutter head armed with chisel-shaped teeth
slowly rotates.
As the machine advances forward,
the cutter head slices through soft London clay,
which falls into waiting wagons.
To prevent a deadly collapse of the clay,
rings of concrete tube are fitted
to create a secure tunnel wall.
Engineers like Joseph Gibbons can't afford
to make mistakes.
One of them plates come down there,
there's 900 kilos, nearly a ton weight,
like it's a lot of weight.
You have no hope against it if it comes down.
Like there's no room for mistakes.
Each complete ring extends the tunnel
by 1.2 meters.
Completing as many rings as possible every shift
drives life underground.
Takes us roughly five to six minutes
to be able to excavate a big enough proportion of ground
to build the next ring, so we've got an excavation
and build cycle around 15 minutes approximately.
We aim to build as many as four rings in one hour,
and carry that through a 12-hour period,
so we can get anywhere between 30 and 40 rings
if we're really working flat out.
The record is 48 meters of new tunnel.
For this to happen, the entire system,
including cranes and trains that bring material
in and out of the tunnel, has to run like clockwork.
The minute logistics falls down,
your tunnel falls down and you lose production
for the day or for the time that's happening.
Effectively, it's a giant logistics project,
and you can see trying to balance
productivity of the machine whilst also getting
materials in and out of the machine to service it.
Every link of this production chain
must succeed.
Right now, a brand new section of tunnel has been excavated,
leaving the train that services the boring machine
short of its final destination.
If the rail track doesn't keep up,
this critical cycle would grind to a halt.
If we don't do the railway track,
then we can't feed the TBM with the concrete rings
that we need to progress, so the guys here,
we need to feed the machine all the way
so this railway track's a crucial part of that.
But constantly building extra meters
of rail track is tough.
The track must be stable and secure,
or there'll be a risk of derailment.
So now Dominic's gonna bolt down these sleepers
to ensure the security of the rail
and the right spaces, et cetera.
(intense music) (tool whirring)
So far, Evelyn is 8.5 kilometers
into her 20 kilometer journey,
and is currently 30 meters below Wimbledon
in south London.
It's vital the tunnel follows the carefully mapped route,
weaving its way around existing cables and tunnels.
On this specific job, we've come within five meters
of the London underground Bakerloo line,
so above us was the London Bakerloo line.
If you stood in the tunnel, you could hear those vibrations
and those trains passing by.
And whilst Evelyn bores her own path
through underground London,
the excess clay mounts up at an astonishing rate.
The material that we're excavating in here,
the London clay, that's governed
a lot of the process for the entire job,
so this allows us to use the particular tunnel machine
that was specified for this job.
The only thing we may come across
is the old clay stone from compaction
over the millions of years that it's been laying there.
So this is coming straight from the base,
taken directly out of this skip.
The train will journey approximately 10 times
in and out of the tunnel in one day,
helping to take full skips of clay up to ground level.
(uptempo music)
People take power for granted, really.
We're here delivering the systematic infrastructure
that can allow that to happen at the flick of a button.
After a grueling shift
in hot, cramped conditions,
the team has laid 30 rings, or 36 meters of new tunnel.
We're all happy that the shift are going home now safely,
but it doesn't stop for long,
after about 10 minutes the next shift
will be in there for the night shift,
and then the whole process will be repeated again.
Projects like this will ensure power
continues to flow into our cities,
allowing engineers the world over
to keep the lights switched on.
(exciting music) (crowd cheering)
It's 10:00 p.m. in Las Vegas,
and on Freemont Street, this means showtime.
The world's largest LED screen consumes over 9,000 kilowatts
of electricity every night.
It's all operated from this control room.
From here, a complex network of fiber optic cables
transmit signals to each LED light.
The video is played back by eight media players.
Each player plays a section of the canopy,
because the canopy is separated into eight sections,
but once it's all together and it plays in sync
it looks like one seamless video.
(exciting music)
It's Chris Bell's job to ensure
all 12.5 million LED lights are working.
All right, so right now on the video screen
it looks like two LED circuit boards have gone out.
It's gonna require me going into my lift,
going up to them, and replacing both of them.
(energetic rock music)
It's close to midnight,
and Chris' work is just beginning.
(energetic music continues)
The reason why we do the maintenance
at 2:00 in the morning on the video screen
is because we can't see it during the day.
As light comes through, the screen,
and actually washes it out.
Every one of the half a million circuit boards
must be kept in perfect order.
And now that those circuit boards
have been replaced for the next show,
the public is gonna see a perfect screen.
(light music)
Cities the world over
rely on highly skilled engineers, crane operators,
even pilots, to keep the power flowing.
Without this hidden army of workers
toiling around the clock,
transport networks, communication systems,
lights, even hospitals will all shut down.
(helicopter whirring)