02x04 - Perpetual Power

[bunniefuu]

[relaxed music]

We really wanted to innovate in a way

so when you combine with wind and solar,

you could actually be competitive

and even cheaper than fossil fuel.

And this really drove
a lot of our innovation

to come up with a combination
of conventional physics,

technology for speed,

with some of the latest
innovations in AI software

and material science,

to create an energy storage breakthrough.

[dramatic music]

A global technological
revolution is underway.

We think in the next 10 years,

you'll see more innovation
than we've seen in the past 50.

Driven by passionate, dedicated individuals

intent on shaping a new world.

I wanna create something new.

I want to create something
that gives me the sense

of creating new life.

This is why I'm here.

A greener world.

This is the last call to action,

that we have to develop the solutions

that are protecting our planet.

A better world.

I have a family, and when I think about

the life I want them to have
and their children to have,

I want them to experience the world

where they can travel
and live without worry.

And that gets me up and going every day.

Together, they are pushing engineering

to its limits.

Human creativity is the
most tremendous power.

And if you set a target,

things that you never thought
possible become possible.

Creating extraordinary machines

that can help the planet
and humankind in the future.

[relaxed music]

Engineers are transforming
the way we power the world,

replacing old carbon-intensive technologies

with clean, renewable sources of energy.

And the speed of change is unprecedented.

The energy transition that's
happening at the moment

is a complete paradigm shift.

Rather than big centralized
thermal generation

burning coal, burning oil, burning gas,

we're now decentralized,
solar, PV all over the place.

Wind and solar, which are
now commonplace really,

they were almost nonexistent.

They were just a minority
thing 20 years ago.

But the meteoric rise of renewable energy

has consequences for
our electricity supply.

While coal and gas fired power stations

can generate electricity
whenever you need it,

renewables are intermittent by nature.

So we need a backup
plan for when the wind stops

or the sun goes down.

So the solution to intermittent power

provided by renewable energy
is to provide power quickly,

using energy storage devices.

Teams of engineers are searching for ways

to store green energy
with mechanical batteries.

So that when extra power is needed,

these devices can bridge the gap,

instead of relying on more
polluting sources of electricity.

The ultimate solution really
is to have much, much more

energy storage built into the grid,

so that at time when
there's a surplus of energy,

such as when the wind's
blowing very strongly

and the sun is also shining,

one can save energy and store it.

We're gonna need a lot of
innovation for new technologies

to be able to store this energy

so that renewable can generate

and we can utilize that
when the grid needs it,

when the demand is.

The success of the green energy revolution

depends on these engineers
and their marvelous machines.

If we were to keep increasing
the amount of renewables

on the grid, but we didn't
implement energy storage

at the same time, our grids
will start to get unstable.

We'll start to have more
and more frequently

periods where power wasn't available to us.

Already there are ominous signs

of what a future might look like

without enough energy storage.

In August, 2020, California
was about to experience

a glimpse of this
potentially devastating future.

The most extreme heat
wave of recent decades

was wreaking havoc on
the western United States.

Elliot Mainzer,

CEO of the California
Independent System Operator,

was paying close attention to the weather.

August of 2020 saw a heating event

that hadn't been seen in many, many years.

It was simultaneously extremely hot

in just about every part of
the Western United States,

with temperatures well
into the a hundred degrees

in California and in
many parts of the region.

It was what we referred to as a heat dome

that sat over basically the
entire western United States.

Then sweltering Californians

were suddenly confronted
with another rare event.

From 6:30 PM on the 14th of August,

their electricity was suddenly cut off.

[dramatic music]

It was the first time that
California had experienced

any types of rotating outages

from shortage of electricity in 20 years.

This shortage may seem surprising,

as California has invested heavily

in green energy generation.

In fact, during the spring,
they have so much solar power,

they export it to neighboring states.

California is first and
foremost, very blessed

to have a very significant
solar energy resource.

We've had a, you know,

we've have over 15,000
megawatts of solar operating

on the high voltage grid
and also behind the meter.

Lot of rooftop solar in California.

So with enough solar panels to power

nearly every household, why did California

run out of electricity during a heat wave,

when there was plenty of sunshine?

The answer was all in the timing.

As the sun went down,

power-hungry air
conditioning systems stayed on.

So the supply high of solar power fell

while demand for electricity remained high.

In the evenings, California often imports

surplus electricity from neighbors,

but this time, they
couldn't rely on other states.

It was so hot in these other areas

that they needed that
electricity for their own customers

and didn't have as much
surplus to sell in California.

And that put us into a
really stressed situation

during a time of the day

when we simply don't have enough capability

to ride through those types of conditions.

Planned energy shutdowns
were the only solution.

The result was hours
of blackouts for two days,

affecting nearly half a million people.

If California could have
stored more of the solar power

generated during the
day to use in the evening,

the crisis could have been averted.

When solar power panels
produce more electricity

than is being used by homes and businesses,

the surplus energy can
instead charge batteries.

Then when solar panels
are generating less power

than is needed, the batteries can discharge

their electricity to the grid,

making sure there's
always enough for everyone.

Since the blackouts, Elliot
has been investing heavily

in batteries, but that won't be enough.

Today, the primary battery
storage resource on our grid

are four-hour lithium ion batteries.

And they are going to continue to grow

in scale and scope here in California,

but they are not go going
to be sufficient on their own

to carry all of the load
of the transformation.

The state's capacity has increased tenfold,

to 2.5 gigawatts, but Los
Angeles alone uses 6.5 gigawatts,

and lithium batteries can't
provide power for long enough

to get through the night.

We are going to need
longer duration storage.

You want a diversity of supply.

You know, you don't want
to have such a dependence

on a single technology.

California is ahead of the curve,

but all over the world,
renewable energy is growing fast.

Without a revolution in energy storage,

the world faces mass blackouts.

Electricity grids need energy storage

that is cheaper than fossil
fuels to be competitive.

They need them to be long-lasting

to provide power for days or even weeks.

It must also be fast-acting
to respond rapidly

when the demand spikes.

But above all, they need to
store vast amounts of energy,

to help the world switch
over to renewables.

[relaxed music]

One nation that's attempting to build

a giant energy storage
system is Switzerland.

The Alpine country boasts
over 600 hydroelectric plants,

but this knowhow in
capturing energy from water

is being taken to the next
level here at Leman Dam

to build a huge water
powered gravity battery

known as a pump storage plant.

Deep inside the mountain,

a turbine hall will connect
Dam Leman to Lake Mut,

one and a half miles above sea level.

A 2,000 feet difference in
height between the two reservoirs

will allow them to store energy.

When there's surplus electricity available,

the gravity battery can be charged

by pumping vast amounts of water upstream

to fill up the lake.

The gravitational potential energy

of the water in the upper lake

can be released to generate electricity

whenever it's needed.

The pumps will then rotate
in the opposite direction,

acting as turbines, generating electricity

and sending it to the grid.

The engineers aim to
generate enough electricity

for the Leman Dam to supply up to a million

Swiss homes at peak power.

[dramatic music]

In January, 2010, energy company Axpo

started building one of the
biggest batteries in the world.

The project would be
one of the most ambitious

engineering feats ever
attempted at such a high altitude.

Overseeing the construction
of this vast pump storage plant

was project manager, Martin Husler.

This was a huge work,

which has to be done with a
maximum of 700 people here

and they work together.

It was a huge construction site.

With no road access permitted

to this protected part of the Alps,

the engineers had to find a solution

to lift all the necessary
building equipment

to the top of the mountain.

So the team built two cable systems,

each spanning just under a mile,

that could lift the equipment
at 10 miles per hour.

We had two aerial cable base.

The first cable way has
a capacity of 40 tons.

And the second cable way
has a capacity of 30 tons.

And all the machinery was
taken by the aerial cable ways

to the Lake Lehman and to the Lake Mut.

Next, they had to dig
through a wall of rock

to the center of the mountain.

Boring machines excavated
a two mile long access tunnel

through which the team
could bring the equipment

from the top of the cable way.

Then the team used expl*sives
to excavate the caverns.

Before collecting up the rubble

to make concrete for the project.

[relaxed music]

The rocks were excavated from the caverns,

were crushed, and
prepared for the concreting,

because this was the main
material for the concreting

from the liner in the cavern.

The builders produced enough concrete

to build 700 suburban homes,

and even more concrete
was needed for the dams.

Most of the this crushed
stone was transported

with the aerial cable way to the Lake Mut

and was used for
concrete of the gravity dam.

This structure will be the longest

in Switzerland, and it will
triple the capacity of the lake.

The altitude of the dam is


and this is the highest in Europe.

So this was also a logistical challenge.

The team had to excavate two main caverns

out of solid rock,

a powerhouse cavern for
turbines and generators,

and a second cavern to
house the transformers.

Then they had to line
both caverns with concrete

and build arches to reinforce the structure

to withstand the weight of
the mountain above them.

The whole plant with all the tunnels

was approximately 400,000 cubic meters.

And as a comparison, our main cavern

is approximately 15%
larger than the interior volume

of the St. Paul's Cathedral in London.

[dramatic music]

The cavern was finally ready

for the transformers to be installed,

but there was an issue.

They weighed over 200 tons,

which was too heavy for the cable way.

The solution was for the engineers to fit

a funicular rail system
into an access tunnel,

which could lift up to 220 tons.

Then the team built four pits

for the turbine and generator units.

These would weigh too
much for even the funicular,

so instead they meticulously
assembled them in situ.

First came the enormous pump turbines.

As these blades rotate,

they transform the
kinetic energy of the water

into rotational energy.

The one that has a power of 250 megawatts

and its design has nine blades.

And in pumping operation,
the runner turns in this direction

and the flow goes through these channels

and goes to the Lake Mut to store energy.

This allows to fill Lake
Mut in about 40 hours.

And in turbine mode,

the water is coming from the Lake Mut,

going through these channels,

and the water flows
through this channel out

and is going to the Lake Leman.

And for all four runners,

we have a total discharge of


That's enough to fill

four Olympic swimming pools every minute.

Finally, the team assembled the generators,

each weighing 360 tons.

[tense music]

To generate power,
operators open the valves

and water flows into the turbines.

The generators convert
the rotational energy

into electrical energy.

The Lake Leman pumped
storage site took 10 years to build.

And it came online in 2020.

The feeling after we have
successfully done the project,

it was great of course,
because this is a huge project.

It takes a long time to
fulfill all these requirements,

and we are still working on it.

It can now provide

a massive one gigawatt of power on demand,

the equivalent of a
typical nuclear power plant.

It is very important to have this

pump storage power plant,

because we are able to store a large amount

of excess electrical energy

produced by solar and wind power.

The Leman energy storage plant

can provide Switzerland with green power

even when the sun or wind drops.

[relaxed music]

Pump storage gravity batteries like this

were first developed here
in Switzerland in 1907.

Today they're the leading form
of energy storage worldwide,

with some of the biggest
in the US and China.

But they take a long time to build,

so as renewable energy grows rapidly,

other solutions will be vital.

Pump storage, it's near its limits now

for several reasons, the
main reason of course,

is that you need a convenient mountain,

and convenient mountains
usually don't exist

anywhere near centers of population

where storage is most needed.

It also has other problems in
that most pump storage systems

are quite slow response.

To get a lot of water flowing takes time.

So some of the grid
services which are needed

demand something which
can respond in under a second,

for example,

and certainly a pump storage
system can never do that.

The supply and demand of electricity

can change very suddenly,

such as the power from a solar farm

when a big cloud drifts overhead.

So in order to keep the grid stable,

engineers must build systems
that can respond rapidly.

[relaxed music]

Inventor Peter Frankel is a
pioneer of renewable energy,

creating novel wind turbines

and the world's first
commercial scale tidal turbine.

So he's well placed to understand

the need to solve this problem.

I decided I'd like to
get into energy storage,

and I was looking around
for some clever way

of ideally using mechanical
engineering of storing energy.

Peter was fascinated by the mechanism

inside a grandfather clock in
his home similar to this one,

a family heirloom.

Basically it has some very heavy weights,

and those weights under
the influence of gravity

would like to fall down,

but they can't because
they're hanging from wires

connected to the mechanism.

So if I put the key in and wind the handle,

this slowly raises the weights,

and the energy from my
muscles goes into the weight

and the weight then will
be energized basically,

and ready to return
the energy to the clock.

This clock is 300 years old,

and actually you could leave these weights

for another 300 years
if you did nothing else

and no energy would be lost.

But if we start the clock
so the pendulum swings,

now the clock has started to tick

and both the weights in
fact will slowly descend.

So, you know, it's a incredibly durable

form of energy storage.

[playful music]

Peter's idea was to scale up the mechanism

in a grandfather clock to
store huge amounts of energy.

To be a success, it would have
to respond in under a second.

To turn the concept into reality,

Peter founded Gravitricity.

He wanted to build energy
storage units underground.

Peter appointed engineer Miles Franklin

to oversee the project in Scotland,

as he had to self isolate in London.

To store a lot of energy,

you need either a lot of
mass or a lot of height.

So in order to get to
very interesting levels

of energy storage by lifting
masses, it's good to go down.

It's also then once it's
underground, it's hidden.

So you can do it under a
city, under a football pitch,

wherever you liked, in
order to store energy,

and then without having problems

with wind and weather
and all these other things.

And so we started to look
at both existing mine shafts

that are no longer being used for mining,

and also the idea of sinking new shafts

specifically for energy storage.

Before going underground,

Miles was in charge of
building a tower prototype

to prove it could provide power rapidly.

The team filled two steel containers

with over 50 tons of high density ballast.

This would store energy when lifted up

and release it when lowered down.

The 30 foot tower was then lowered

onto the containers and secured.

There was some, you know,
scary moments along the way

when we're moving very
heavy things and lifting them.

So there's a sigh of relief
when they're all in place.

Once it was all assembled,

they were ready to store
energy for the first time.

We got to the moment we
were gonna lift the weights.

We had quite a lot of the
engineering team on site.

So yeah, there was some,
there was some tension.

They used power from the grid

to raise the weights and
charge the system with energy.

[tense music]

For that lift, it's the first time

that the whole structure
is supporting the weight.

And you'd expect, you know,
as you lift, some strange noises

as the structure kind of finds its place.

When the weight reaches
the top of the tower,

the system is fully charged.

We can stop. We can pause.

We can hold that energy
for as long as we want.

But how fast can they return power

to the grid when it's needed?

Senior test engineer, Jill Macpherson

knows how important that is.

Right now, we're going through a transition

from using fossil fuels
towards using renewable energy

to generate electricity.

But that means that
the grid is less stable.

With conventional power,
we have these big generators

that provide a lot of
stability to the grid,

but with renewable energy devices,

they don't really provide that.

Sure, we wanted to be
able to go from zero to full

exporting power within a second,

so that all the devices on
the grid can operate safely.

All systems are go.

[dramatic music]

To generate back to the
grid, the weight is lowered.

The weight pulls down on the steel rope,

which turns the winch,

and then by the gear box turns the motor.

The motor acts as a generator,

so then we're putting power
back into the electrical cable,

fire the power electronics
straight into the grid.

The tower had successfully

generated electricity, but
for the first few seconds,

the power supply had fluctuated too much.

And so what we find is when
we accelerate really quickly,

the weight starts to bounce up and down,

and that bouncing weight
becomes a variation in the power.

So what we need to do is find solutions

to be able to accelerate really quickly,

but then have that power output

from our system quite smooth.

So we need to try and
find some way to fix that.

The team must find a solution

to generate a smooth
power supply more quickly

when the weight starts to drop.

Although the concept may seem simple,

smoothly lowering a weight of 50 tons

in a fraction of a second

involves intricate mathematical modeling.

Analyzing the dynamics of
the weights and the movements,

and then designing them
is actually quite complex.

And so that was something
that took us a while to get right.

One month later, Miles
and Jill have a plan.

We are testing.

After many simulations and tests.

Its clear.

They think they figured it out.

Okay. So three, two, one, go.

[tense music]

If we want to go from zero to full power,

but have smooth power at the maximum power,

what we could do is apply
a force that cancels out

the tension oscillations in the cable,

and then that corresponds
to smoother power.

[tense music]

Great.

To find out if it produced a useful source

of power in under a second,
they must analyze the results.

In this last set of tests that we just did,

you can see that the
power is much more smooth.

It's a straight line and
that's what we're looking for.

We went from zero to
full power in 0.96 seconds.

Gravitricity's prototype has proven

it can respond rapidly
to the demand of the grid,

a significant improvement
of a pump storage,

which can take minutes.

In July, 2021, Peter
Frankel was eventually able

to make the long journey
from London to Scotland

to see the tower for the first time.

A bit better than the
grandfather clock, yeah.

Doesn't have such a nice
face on the top of it, but yeah.

Now that this prototype
has proven his theory,

Peter has big plans for the next stage

of his energy storage system.

In the near term future,
I think we're looking at,

you know, initially systems,
a few 500 meters deep

and six meters diameter.

So it's like a railway tunnel turned on it,

you know, vertically.

We hope and expect that
gravity based energy storage

of the kind that we're trying to develop

could have a massive
impact in terms of facilitating

the wider use of intermittent renewables.

A typical system would
store enough electricity

to supply 13,000 homes for two hours.

Gravitricity hope to build

their underground mechanical batteries

all over the world to store green energy.

[relaxed music]

Meanwhile, back in Switzerland,

a startup called Energy Vault are building

another type of gravity battery.

The goal is to store energy
as cheaply as possible.

CEO Robert Piconi
understood that the only way

to move to 100% renewable
power was to undercut the price

of electricity generated by fossil fuels.

You have to be able to
essentially compete with something

that's about five to six
cents a kilowatt hour.

And the good news is solar
and wind now is just a few cents,

one to two cents of kilowatt hour,

so the economics really work there.

You therefore have to target storage

that must be between three and four cents

to have something
that at least is on parity

with fossil fuel and
therein lies the challenge.

To meet this challenge,

the team came up with a specific design.

The energy vault won.

A crane with six arms
that could lift heavy bricks

and stack them on top of
each other to store energy.

Then to release that gravitational energy,

the cranes lower the bricks
back to the ground one by one.

By building a tower made of
thousands of heavy weights,

it could store large amounts of energy

and therefore bring down the cost.

And by using mostly
tried and tested machinery,

they could build it quickly,

But first they had a
thorny issue to tackle,

so they built a quarter scale system

to try and find a solution.

The problem is that when heavy objects

are lifted by a crane, they
can swing like a pendulum.

One of the main challenges
we have in utilizing the system

to move large objects is
the environmental impacts

on that object in movement.

And it's a very important problem

when you're moving
large things like containers,

for example, that are at the ports,

and when the cranes are moving them,

they will sway and impact the ability

to precision place them.

When we're moving
around 35 metric ton bricks

that we have to stack at height,

it's very important that we
be quite precise with that.

And so that's was one
of the major challenges

was to solve for this pendulum effect.

When the trolley on the
crane moves along the arm,

the weight below starts
to swing back and forth,

making it almost impossible

to precisely place the
weight in its new position.

We had actually thought
that the crane industry

had solved this already for
movement of things in the ports

and these large containers.

But as we talk to other partners
and suppliers in the space,

it hadn't been solved.

And so we had to develop
the algorithm for that ourselves.

And it's a very important algorithm,

because it's not only necessary

for the precision placement of the brick,

but also to deal with any
unpredictable weather events,

for example, a high gust of wind.

So this was fundamental that
we use software to solve this.

So we took concrete barrels
and utilized an existing crane

that we modified to test
the ability of software

to cancel this pendulum effect.

As the test began, an AI control system

could predict how the
weight was about to sway.

It then instantly adjusted
the movement of the trolley

to cancel it out with an
equal and opposite motion.

One of the most
fascinating things is to focus

up on the trolley and to see
the back and forth movement

in light speed so that that concrete barrel

is maintained that consistent velocity,

and just amazing to
see that software at work

and manifest itself from
the modeling to reality.

In January, 2021,

work began on building the full size crane.

But this would be nothing like the cranes

you might see at a construction site.

After laying extremely strong foundations,

the team assembled and
secured the seven sections

that made up the 660 foot high tower.

[tense music]

In the meantime, another team assembled

the three rotating platforms called jibs.

Just one jib of the crane weighs 130 tons.

So just to construct it is one thing,

but then to maneuver it around the site,

we had to use a special
horizontally design hovercraft

system that could maneuver
and shift from the shelter

where it was constructed to a
location where the crane then,

the 600 ton crane could
be attached to that system

and be able to lift that jib up

so it can be constructed
onto the crane itself at height.

Just fascinating and
amazing and just a great job

by the team to pull that off.

The crane stacked the
jibs on swing bearings

on top of each other so
they could turn independently.

Once in place, it was
time to assemble the arms

which support the transport trolleys.

[dramatic music]

Having enough arms of the crane

with enough megawatt motors per arm,

you could generate up
to five megawatts of power

and be able to essentially discharge that

over a period of time, at least six hours,

but ideally up to eight to 12 hours,

in a way that could be reliable.

While the multi-armed crane took shape,

Rob faced a dilemma over
how to make the 40 ton bricks

in a way that was both cheap
and environmentally friendly.

So normally as you think
about making any dense weight

object, one of the easiest
materials to use is concrete.

The problem for us in concrete were many.

It was too expensive.

It was also bad for the environment.

Concrete production still represents

seven to 8% of the greenhouse gases.

So this again required more innovation

for us to think about how
to solve that a problem.

They wondered if the solution might be

a low cost, plentiful material

available at almost any site, soil.

So Energy Vault approached a specialist

in building materials, Simec,

to develop and manufacture their bricks.

We had been working already

on soil solidification for some time.

There are a lot of places
where there are plans

to develop network of
roads, sometimes, you know,

very difficult places.

And the easiest way we
thought was, you know,

to be able to take just the soil there,

you know, dig it out,

compact that material and
give it the ability to solidify.

To make the bricks, head of R&D,

David A Zampini, would
need to adjust their process

to make them even tougher.

These blocks have to be
designed to last 25 years or more.

The conditions that the blocks

would be subjected to are highly variable.

I mean, you can have
places where it's very hot,

very cold, wind.

These blocks are being lifted and put down,

lifted and put down.

So, you know, they go
through a lot of cycles of stress.

Simec came up with
a mixture of soil, water,

a small amount of cement,

and two crucial binding components.

First, a chemical glue.

In terms of the strength,

it has a lot to do with
our chemical admixtures.

You know, creates a strong binding element.

What we call like the
mineral glue of the block.

The second component is glass fibers.

Fibers are actually
incorporated as a means to

arrest any initiation of a
crack that could take place.

What we do with the
fibers is like, you know,

make the material highly resistant to,

especially when it's under tension.

Simec are now investigating

an alternative source of fiberglass

that could be even more
environmentally friendly.

Today, we're looking at recycling

the blades of windmills that create energy.

So it's interesting now
that the same element

that is creating energy has to
be obviously decommissioned

and we can recuperate the
blades and process that material

and actually incorporate
it into the blocks.

This mixture is greener than concrete,

as it contains much less cement,

and avoids the pollution
caused by heavy transportation.

And crucially, it's also cheaper,

which ultimately means a
lower price for stored energy.

But to make the bricks strong enough

to be stacked 500 feet high,
they needed one more step.

When you are paving a road, you know,

you use a roller compactor
and here actually we said,

"Okay, we would use the
same approach," because,

you know, compaction
is the best way to densify

and make a material strong,
but we needed to, you know,

process the material in a different way.

And that means we had to find
a way to compress the material

as much as we can because the compression

and the way the chemicals
work further elevate

the strength and the
densification properties

of the material, which are required

to have the block survive
those different conditions.

The pressure is applied
by a custom-built machine

with 40 powerful hydraulic pistons.

[tense music]

You need a compressive
strength of almost 7,000 tons.

If you think about the weight of a car,

that's about one and a half tons,

and you were to stack
the amount of cars needed

to generate 7,000 tons of force,

that stack of cars would
be as high as Mount Everest.

After 10 minutes of this immense pressure,

the bricks are good to go.

Once part of the system,

each one will be capable
of providing a megawatt

of electricity while being
lowered by the crane,

enough to power over 2,000 homes.

But before they stack
the blocks into a tall tower,

Rob needs to be sure it'll
be safe in all conditions.

Now, one of the parameters in our design

was to be able to build this
at scale almost anywhere,

but there are locations
where there's a strong need

for renewables that happen to coincide

with some seismic
activity, like in California.

And because of that, we
wanted to do another focus

around research and science to deal with

the occurrence of seismic events.

Energy Vault teamed up with Caltech

and UC Berkeley to put the
structure through its paces.

After some small tests, they
built a one to 20 scale model,


bricks carefully stacked

on top of the biggest
shaker table in the US.

You can imagine the atmosphere in the room

as we had the tower constructed

and we're about to
turn on the shaker table.

A lot of anticipation.
[dramatic music]

The giant shaker table precisely simulated

the 7.1 magnitude Ridgecrest earthquake

that hit California in 2019.

As we got into the earthquake,

what we saw is a vibrating of the system

and a shuffling of these bricks,

but the system never
decoupled from the bottom

and resulted in a full
collapse of the system.

Just this tremendous round
of applause in the room,

because our software
modeling and prediction

was actually gonna to be correct.

So as we reconstructed the tower,

We did hit it with a larger earthquake,

the Denali earthquake,
which is up in Alaska,

that was an 8.2 on the Richter scale.

Only a handful of
locations around the world

have experienced
quakes as powerful as this.

None in California have been stronger.

While we were hoping that
maybe it might withstand

that level of earthquake, it did collapse,

you know, pretty readily.

Nevertheless, the tests had proved

the structure could withstand

the vast majority of earthquakes,

which many conventional
structures couldn't do.

The implications for
science and civil engineering,

of the fact that you could
have a discontinuous structure,

not connected with standard mortar,

that could respond in a seismic event

and shuffle and move and dissipate

that heat and energy from a seismic event

and therefore withstand
better than existing structures

was just a tremendous impact
we felt like we were having

also well beyond even our
energy storage structure.

With the safety of the system beyond doubt,

the team were ready to stack the bricks.

The holes allow the cranes
to lift the bricks securely.

Just amazing to see a 35 metric ton object

coming off the ground and going at height,



and not a new thing in
terms of that amount of weight

being lifted, but to have that
done in an automated fashion

and in a way that is
gonna be storing energy

for the first time.

So in this application,
pretty cool, pretty cool to see.

Energy Vault expects to be able

to generate electricity at a cost

of just 6.5 cents per
megawatt hour by 2025,

making it much cheaper than batteries

and competitive with fossil fuel.

The EV1 could be perfect
for storing energy in the day

and giving it back throughout the night.

But we also need a
way to store green energy

that can generate power for days or weeks

if the sky turns gray or
the wind stops blowing.

Luckily, back across the English Channel,

a company is engineering
a new way to store energy

that can provide power for longer periods.

And instead of using gravity,

they want to generate
electricity from thin air.

I'd like to think of it as
an energy storage system

which is a bit like pumped hydro,

which is physically a
very, very large system,

but you can put it anywhere you like.

Chief Technology Officer Gareth Brett

has been developing the system

at Highview Power for 12 years,

working closely with
Birmingham University in England.

What we're looking for is economic means

of delivering energy storage
over a longer period of time

than the typical electrochemical batteries.

Lithium batteries
typically provide electricity

for up to four hours.

Highview's goal is to store
vast amounts of energy

over a long period of time

so they can then generate
power continuously

for days, weeks, or even months.

To do this, they plan to store energy

in the form of liquid air,

which only takes up a
small amount of space.

I've just put some
regular air into this balloon.

In this white pot down here,
we've got some liquid nitrogen.

It's at -196 degrees Celsius.

We're gonna dip the balloon in

and it will get extremely cold.

And the air in the balloon
will now start refrigerating,

and you can see the balloon is collapsing.

That's because the air is getting colder.

It occupies less volume to the point where

the air actually starts
to turn into a liquid.

So if we take that out,

you can just see in the bottom,

there's a little bit of liquid
in the bottom of the balloon.

It's about a 700th of its original volume.

As it warms up, it expands back into a gas.

If we did what we've
just done to the balloon,

to all of the air in this entire lab here,

it would shrink down to a volume of liquid

only the size of this little oven,

which gives you a sense of
how much air you can store

in tanks by keeping it
as a refrigerated liquid.

When power is needed,

this system expands the
liquid back to normal air

to generate electricity.

This rig demonstrates
how we get electricity

back out of liquid air.

So the liquid air comes up the pipe here.

You can tell that the pipe
contains cryogenic fluid

because it's frosted up,

and down into this white tank.

And in there is a bath of hot water

surrounding a coil of
stainless steel pipe work.

And it gets evaporated back into a gas.

As it warms, the liquid turns back to air,

but at a very high pressure,

as it can't yet expand in the pipes.

So at this point, we've got gaseous air

coming back up this pipe,

and that feeds up along
this piece of pipe work

and down to our little air motor.

As the high pressure air finally expands,

the fast moving gas
drives a rotor to spin rapidly,

which generates electricity.

So we're turning stored
energy in the form of liquid air,

back into mains power that
we're using to drive the fan.

In 2018, Gareth's team built

a demonstration plant
in Manchester, England

to prove that technology
works on a commercial scale.

It was a system that could
use off the shelf components

from major industries like
the industrial gas industry,

which is where we get

our refrigeration systems
from to make the liquid air,

tanks available from
the construction industry,

and turbines and
generators that, of course,

come from the utility sector.

At Highview's liquid air storage plant,

air is cleaned up, compressed,

and put inside a large
industrial scale refrigerator

where it is condensed into cryogenic fluid

at -320 degrees Fahrenheit.

The cryogenic fluid is
then stored in large tanks,

which can hold enough air

to fill the Royal Albert Hall in London.

To release power, the cryogenic
fluid is pumped to a heater

where it evaporates back into a gas

before driving a turbine
generator to produce electricity.

The idea works in principle,

but there's a fundamental
problem, the efficiency.

Refrigerating the air so
it's cold enough to liquidize

takes a huge amount of energy,

and turning the liquid back to gas

takes a lot of power to warm it back up.

This means most of the electricity

is wasted in heating or refrigeration,

and only 25% gets returned to the grid.

But Gareth's team relished the challenge.

One of the things that
we've always sought to do

is to improve the efficiency of the system.

We hit upon the bright idea,

wouldn't it be a nice
environmental thing to do

is to not pollute the environment
by dumping heat into it,

but hold onto that heat
and then use it later

when we want to expand the compressed air

when we're generating electricity.

The heat generated by turning the air

into liquid is stored and later reused

to warm up the liquid
air, but that's not all.

The cold generated by
evaporation is also stored

and later used to chill the
air that's being liquidized.

When we're expanding that gas,

we capture some of the cold
that the cryogenic fluid had,

and we feed that back into the refrigerator

to improve the efficiency
of the refrigerator.

Highview claim that
recycling the heat and cold

boosts the efficiency hugely, to 70%,

and that the system has other benefits.

Highview, it's very
kind to the environment.

The working fluid is air.

We take it, clean it up a little bit,

store it for a while, and give it back.

So no tail pipe emissions,

no bad things used in its processing.

It's about as good as it gets

in terms of environmental footprint.

But the key to Highview's long term storage

and almost endless supply of power

is their cryogenic liquid tanks.

Javier Cavada is a board director.

These two columns that
you see here, the white tanks,

these are tanks that you find
in everywhere in the planet,

in hospitals for liquid oxygen,

in factories for liquid nitrogen,

in houses, in industrial
areas, totally commoditized.

The ready availability of these tanks

means it's cheap and easy to add more

for a longer lasting store of energy.

If you want to add motivation,

you just need to add more tanks,

but you need to add a new charging station,

a discharging station.

The more energy you are storing,

the lower cost you
need to store that energy.

The economies of the
scale of this technology

are simply amazing.

Even seasonal storage of power is possible,

where surplus solar energy in summer

could be stored for use
during the long, dark winter.

Ultimately, electricity grids will need

many different kinds of energy storage,

depending on how much they need,

how long they need it for,
and how fast it must respond.

I'd like to see Highview
really widely deployed,

but alongside other long duration

and shorter duration technologies.

So, you know, I'm looking
for the broad adoption

of energy storage, but not just that.

I'd like to see technologies advancing

so we've got new competing
technologies coming through

that are better performing,
cheaper, and quicker to deploy.

As we develop our full-scale systems,

we really believe that can
become part of this energy system

as it changes and
allow us to kind of fulfill

these big ambitions of
decarbonizing our grids

really quickly.

The energy transition is gonna be massive

over the next 30 years,

is gonna be in the trillions of dollars,

and therefore accelerating
the need for the innovation

to be able to deploy different technologies

to reduce the greenhouse gases.

Make sure we can hit net zero in 2050.

That is still a gigantic challenge,

but the more systems
like ours that we deploy,

the better the opportunity we've got

of hitting those targets.

Let's hope we can turn
what looks like, you know,

a train wreck into something
that looks like plain sailing.

By providing us with perpetual green power,

these giant mechanical batteries

could play a crucial
role in saving the planet.

[relaxed music]

[dramatic music]

[icon twinkling]

[cheerful jingle]