Original subtitles

The Hoover Dam, the crown jewel of American infrastructure and one of the

ambitious projects of the early 20th century.

It was a bold idea on a scale that truly had not been seen in dam construction

before. At the time of its completion, it was the largest electric power

generating site and concrete structure in the world.

Today. The Hoover Dam plays an instrumental part in providing water to

million people.

But now we're curious. With modern technology, could we update the original

bring it in line with today's energy needs?

Could we rebuild the Hoover Dam? I think we can. Should we build the Hoover Dam?

That's a different question, a more complex question.

With the climate crisis, we're going to need to be making some big changes to

the way we do things.

Here's the plan.

We're enlisting the world's top engineers.

In situations where a hydro dam already exists, math is always going to prove

out very solidly on the side of refurbishing and updating.

Implementing the heaviest machinery.

Hoover Dam can be retrofitted. We have explored the challenge and we know we

do it. And all the money it would take to revive one of the greatest feats of

engineering ever constructed.

Imagine the world's greatest wonders reimagined.

We're wondering, how long would it take?

How much would it cost?

How many workers would we need? Could we even do it if we built it

today?

The southwestern United States is hot.

Dry and barren. But today, this desert landscape is home to the most rapidly

growing population in the country.

All thanks to this marvel of engineering.

The Hoover Dam represented progress, moving forward, electrification,

irrigation in a remote region of the United States.

The dam was very typical.

of American expansion into the West.

It was a conquest. It was a controlling of nature and turning nature's power to

beneficial ends.

The Hoover Dam was built along the Colorado River between Arizona and

It's the lifeblood for 18 million people, providing not just a constant

electricity, but also regulating the precious water supply from the Colorado

River. Today, it's a popular tourist destination, drawing nearly one million

visitors every year. The Hoover Dam is an incredibly striking dam.

It's iconic for good reason. It's the tallest concrete dam in the U .S. The

Hoover Dam stands as high as a 60 -story skyscraper. And its base is thicker

than the Washington Monument is tall.

The power plant's 17 generators produce enough electricity to power 1 .3 million

homes.

All that power comes from the Colorado River, entering the dam through four

intake towers.

Each one is about the same height as the Empire State Building.

From there, the water spills into two 30 -foot diameter pipes.

Racing toward the power plant, At 87 miles an hour, this

monsoon of water generates electricity at a 3 million horsepower clip, or the

same engine power as 5 ,000 semi -trucks.

Construction on the Hoover Dam began in 1931, just as the country was entering a

new and dark chapter.

The stock market crashed.

And the Great Depression started, leaving Americans desperate for work and

desperate for some sign that the promise of the country was still there.

The Hoover Dam is born of its time in the Depression as a leap of faith

into the future, but also as a short -term investment in putting people back

work. As the Great Depression unfolded.

Hopeful laborers descended on the barren desert job site.

For them, building the Hoover Dam was more like a gold rush than a

project. You can imagine for the laborers who built the Hoover Dam in a

site to see this gargantuan project in concrete rising up from the

canyon floor.

It was unlike anything they had ever seen before.

But soon, laborers realized they'd signed up for a near -impossible task,

the mighty Colorado River.

The biggest problem in building a dam is what to do with the water during the

construction of the dam. The builders developed an ingenious system of

through the bedrock to carry the water around the construction site.

This enabled the construction to continue and not be flooded.

When two of the tunnels were complete, the workers used the excavated rock to

form two massive cofferdams, or temporary dams, to divert the water

tunnels. These were enormous undertakings that enabled the

stay dry and to proceed on schedule.

But the greatest achievement of all?

was building the massive concrete dam.

It required 6 .6 million tons of concrete, enough to build a four -foot

around the Earth at its equator.

The triumphant story of the Hoover Dam's construction is legendary.

But for civil engineers Francisco Tessi and Kathleen King, the Hoover Dam is a

testament to how engineering can reshape the world.

As a dam engineer, this is one of the most iconic jobs that exists.

At the time of its construction in the early 1930s, nothing like it had been

achieved before, and many thought it couldn't be done.

So what if we wanted to build a 21st century version of the Hoover Dam?

We construct large dams because they're useful for things like flood protection

drinking water and irrigation water and other municipal and industrial uses of

water but other water users like you know the critters downstream have come

rely on the natural hydrology hydrology is the

science of water movement distribution and management with the natural

environment and the hoover dam had a massive impact on the native hydrology

the Colorado River by creating Lake Mead, the largest reservoir in the

States. The biggest challenges of building a large dam nowadays is the

environmental aspect of it.

A large dam project on the scale of the Hoover Dam causes environmental

devastation, flooding, changing ecosystems.

Look no further than China.

to see the massive environmental impact of the world's largest dam.

Completed in 2003, the Three Gorges Dam is five times the size of Hoover.

But its construction displaced 1 .3 million people and

created a reservoir over one -third the size of Rhode Island.

NASA estimates that the dam and reservoir even slowed the rotation of

making each day approximately 60 nanoseconds longer.

Many engineers, myself included, are conflicted today because the benefits of

low -carbon electricity source are really powerful.

So now we have to figure out, do the benefits outweigh the risks?

There's no denying the power of hydropower.

It's the planet's number one source of renewable energy, accounting for over 50

% of all green power and nearly 20 % of total power generation capacity

worldwide.

Entrepreneur Kevin Mullen sees a groundswell of opportunity in the dams

already built.

In situations where a hydro dam already exists, The environmental impact is,

you know, it's a no -brainer that it's been done already, and therefore to be

able to use it and increase the utility of that location, that's going to make a

lot of sense in a lot of locations.

The idea of a Hoover Dam retrofit excites engineers to see the potential

integrate a technology called pumped storage, a mega -scale form of energy

storage capable of recycling hydropower.

In a pumped storage project, you have two water bodies, and those water bodies

are separated by some elevation difference. So you've got an upper

a lower reservoir.

The two bodies of water are connected, and water can be pumped from the lower

body of water to be stored in the reservoir above.

For a traditional hydroelectric project, water flows downstream and the pressure

of that flowing water moves a turbine, which is connected to a generator, which

generates electricity to put on the grid.

Rather than letting that water continue to flow downstream, some of that water

would be diverted and pumped back upstream so that it could be released

when more generation is needed.

But all that pumping churns through a lot of electricity.

So these days, engineers are using renewable energy to fuel the pumping,

creating what's known as a clean battery.

A clean battery is something that we can use to store generation from renewable

resources like solar and wind so that we can use that generation when the wind's

not blowing and the sun's not shining.

Pump storage is a great way to do this.

You're charging the battery when you pump water up and the battery is

discharging when you release water from the upper water body to the lower water

body. Overhauling the Hoover Dam into a clean battery is a radical proposal.

Is it even possible?

As an engineer, I can tell you Hoover Dam can be converted into.

a pumped storage facility.

There are other things that impact whether we can do it, but let's say the

statement is yes.

So can we imagine how we'd transform the Hoover Dam into a pumped storage

facility?

Could it generate even more electricity than before?

And how would it even work?

It's going to be an epic feat of engineering, lining up all the parts,

and people we'd need.

If. We built it today.

We're imagining what it would take to build one of the great engineering feats

of the 20th century, the Hoover Dam.

The Hoover Dam was an attempt to control the water, particularly to control the

mighty Colorado River, which ripped through the canyons of the West at an

incredible speed.

It was an amazing technological accomplishment.

The Hoover Dam helped transform the American West, providing unemployed

with work during one of history's darkest times.

But these days, there's another uncertain future on the horizon when it

our rapidly changing environment.

We're going to need to be making some big changes, and part of that is

a little bit outside the box.

With that in mind...

How could our 21st century dam build help curb carbon emissions?

Like the Hoover Dam, the scale of the clean energy transition is immense, and

need solutions that can deliver at that scale to make sure we do this on time.

Joe Zhu is an entrepreneur focused on carbon -free renewable energy and energy

storage. Storage is going to play a key role in how we decarbonize the

electricity sector.

Because the sun doesn't always shine and winds can be inconsistent, clean

batteries have the ability to transform unreliable energy sources into reliable

power, keeping the electrical grid stable.

As energy consumers, we might take for granted that at every moment, grid

operators have to balance the supply of electricity with the demand.

For a grid operator, Pumped storage is like always having a spare battery

charger in your back pocket.

A lot of generators, like nuclear power plants or coal power plants, don't like

to be ramped up and down. They sort of just like to be set at their output and

stay that way.

Tapping into a clean battery is as easy as flipping a switch.

Other forms of grid -scale battery storage are being experimented with. But

right now...

There's only 1 .2 gigawatts of large -scale battery storage connected to the

electrical grid in the U .S.

That's barely enough to power 400 ,000 homes a year.

Pumped storage tech is an essential part of an ambitious goal set by climate

experts to double energy storage capacity by 2050.

So, what if...

Instead of imagining how we'd build a new Hoover Dam, we re -imagined this

Here's the plan.

Let's imagine how we could create the biggest pumped storage facility in the

world.

That mission will guide every decision we make for our 725 -foot -tall

makeover of the Hoover Dam.

Can we really design the most efficient energy storage solution on Earth?

We can improve the efficiency and maybe produce 20 to 40 percent more power in

the same spot.

And we've got to figure out how we could put it all together.

You would be undertaking a significant effort to construct a tunnel to move

water.

We need to figure out how many people we'd need and how long it might take.

Then, it's time to add up the final price tag.

But before we start calculating costs for this blockbuster remodel of the

Dam, we need to put together a design plan.

So, let's start from the beginning.

The Roman Empire, with their ancient aqueduct system, were the dam building

masters of the ancient world.

using highly advanced hydroengineering to fight flooding and store drinking

water. But dam -building know -how stalled out through the Middle Ages,

going electric during the Industrial Revolution in the 19th century.

It's the same ancient principle as a water wheel, but electrified.

As water flows over the blades of a turbine, it spins the turbine, which in

spins the generator, which then produces electricity for the power grid.

But over five millennia of dam design culminated with the construction of the

Hoover Dam.

The Hoover Dam is an arch -gravity dam, which means it can resist the force of

water through two ways. The force of the water pressure.

wants to move the dam out of the way. It wants to push it downstream.

The water pressure wants to turn the dam over.

Engineers use two strategies to push back against the water pressure. An

which pushes against the cliff on each side of the canyon, and gravity, sheer

weight. The heavy mass of the concrete weighs the dam down, and it's too

heavy. for the water which tries to push it over. By using two strategies to

resist the water pressure, the engineers of the Hoover Dam dramatically over

-designed the dam.

It's been estimated that the Hoover Dam could easily stand for another 10 ,000

years. But now, we're trying to imagine a bright new future for this epic

slab of concrete.

Can we draw up a design plan to transform the Hoover Dam into a gigantic

battery?

If we built it today.

We're trying to figure out how to remodel the 90 -year -old Hoover Dam,

the ultimate clean battery that stores renewable energy as H2O to

release, as needed, and generate hydropower.

That's the big idea behind a system known as pumped storage.

Now, we need to draw up a design for a mega makeover of one of the world's most

famous mega projects.

Building a pumped storage plant is more like putting together a machine than

building a structure.

There's a whole bunch of different parts that have got to work together to make

it hum.

A pump storage facility has four main components.

It has an upper body of water, which we call the upper reservoir. That's where

we store the water, in this case our energy.

It has a lower body of water. That's where the water goes after we generate

power. It has the conduit that ties the upper with the lower reservoir, whether

it's a tunnel or a pipe. And then that pipe will go into this powerhouse. The

powerhouse is where the magic happens.

That's where the turbines are.

The Hoover Dam already has an upper reservoir, Lake Mead, and

it's got a powerhouse, too.

There are 17 total turbines down here, eight on the Nevada side and nine on the

Arizona side.

But what the Hoover Dam doesn't have are bidirectional turbines that can be used

to both generate electricity and pump water back up to the reservoir.

At the top of the dam.

When you look at a pump storage, you're looking at two lakes connected.

And either we're generating power at a given time or we're pumping the water

back up from the lower body of water to the upper body of water.

But we might be able to get away with skipping a powerhouse overhaul.

Another type of pump storage facility would be what's called a pump -back

facility. And rather than trying to reconfigure the existing powerhouse to

reversible equipment, instead you can install a pump station or construct a

pump station at another location to use in conjunction with the existing

generators. And it's been done before.

Welcome to Washington State.

Home of the Grand Coulee Dam, Hoover's lesser -known younger sibling, built

along the Columbia River, a 1 ,250 -mile -long stretch of water that runs from

the Rocky Mountains to the Pacific Ocean.

Grand Coulee is an example of another mega -dam where pumpback facility was

added.

Construction originally began in 1933.

By blocking the Columbia River and creating a massive reservoir, the idea

pump water up into the Grand Coulee, an ancient riverbed formed by Ice Age -era

flooding.

The goal was to reflood the basin and irrigate an area twice the size of

Los Angeles.

But the farmers would have to wait.

After America joined the Second World War, the grand, coolly -damned secondary

function, electrical generation, was fast -tracked to power the war effort.

After the war, they began work on the original plan.

Just as the pumping plant was being installed in the early 1960s, pumped

technology was gaining major steam in the U .S.

Engineers decided to put in reversible pumps.

And back then, they weren't thinking about cutting back on carbon. They were

trying to make money.

Historically, pump storage was used for what's called energy arbitrage. So when

electricity is very cheap, you use that electricity to pump water upstream in

your upper reservoir. And then when electricity is very expensive, you

that water, you generate, and then you're making money by doing that.

The reversible pumps at Grand Coulee.

are still used to play the energy market.

And we could employ a similar principle with pumps powered by renewable energy.

That's the sort of configuration that could be used at Hoover Dam if

Hoover Dam to a pump storage project.

You could make use of the existing powerhouses at Hoover Dam.

and then downstream, perhaps along the lower Colorado River, build a pump

station that would pump the water back behind Hoover Dam.

We have Lake Mead, which is the lake formed by the Hoover Dam.

But we still need a second body of water.

Will we be able to find the perfect lower reservoir?

Or are we in over our heads if we built it today?

We're wondering how we could re -engineer the world's most iconic dam by

it into a pumped storage hydro powerhouse.

But in order for this to work, we'll need to install a pump station at

location.

The biggest challenge we will have nowadays is to find where that other

reservoir will be. We have Lake Mead, which is the lake formed by Hoover Dam.

Now we need a second body of water.

Lucky for us, The perfect lower reservoir already exists 18 miles

Lake Mojave.

Okay, so here's our design plan.

We use the powerhouse inside the Hoover Dam, and Lake Mead as our upper

reservoir.

Our lower reservoir could be Lake Mojave. And we could build a pumping

and a pipeline.

to connect the two bodies of water. But there's a problem.

Water is a very sensitive resource in this area.

They're into a 20 -year drought now.

Before 2001, the water line was 12 stories higher than it is today.

Retrofitting the Hoover Dam for a pumped storage facility is going to have

meaningful impact on how the river downstream of the dam flows.

The environmental and regulatory processes associated with that type of

can take several years to process.

So how energy efficient could a Hoover Dam remodel be?

In some ways, pumped storage can seem like that water could perhaps just cycle

forever.

However, it takes more electricity to move a volume of water to the upper

reservoir than you generate from that same volume of water when you release it

to the lower reservoir.

I think when it comes to repurposing the Hoover Dam for a pumped storage

facility, it's important for us to look at the overall operating efficiency of

the system. The plans for this retrofit require tens of miles of pipelines.

And on top of that, you also have to spend energy to push the water through

those pipelines all the way back to the top of the dam.

So, before we get started, we better do some due diligence into our alternative.

And that brings us to Medina County, Texas.

Well, you've got to have energy storage because renewable energy is

intermittent. But the wind doesn't always blow. The sun doesn't always

So if you want to have baseload power, so the power is always there when you

need it, you've got to have a way to dispatch it.

Meet Howard Schmidt, the energy storage innovator behind geomechanical pumped

storage, a different kind of clean battery.

Geomechanical pumped storage is physically basically identical to

storage. But the big difference is groundbreaking, literally.

Instead of pumping water from a lower altitude to store it at a higher

when there's excess energy on the electrical grid, you charge the battery

pumping water from a large artificial pond down 1 ,640 feet into the Earth,

storing it between layers of rock in a highly pressurized state.

where we're actually deforming the rock and then lifting it ever so slightly. So

that adds pressure.

When you need power, you let the water come back up through the well. It goes

into a turbine, and then that water is then discharged into the pond. So it's a

closed cycle system.

The spinning turbine sends electricity to the grid.

The powerhouse here is still under construction.

But with the flick of a switch, you can see the power of geomechanical pumped

storage. on full display.

It's just a pressure test right now, pumping water up from over 100 stories

below ground.

But if this water stream was generating electricity, it could produce as much

energy as a single wind turbine.

This is the revolutionary technology behind this clean energy storage

Traditional pump storage requires the use of mountains, which isn't available

everywhere. I lead a team of really talented people trying to transform the

we store energy and decarbonize the power grid.

But how does geomechanical pump storage rank on the energy efficiency scale?

Geomechanical pump storage actually operates at higher pressures than

traditional pump storage.

This allows you to use less water and be more efficient.

We've actually observed 90 % hydraulic efficiency in this one. We think we can

improve that.

So instead of using excess power to pump water back behind the Hoover Dam, could

we just build a geomechanical pumped storage facility right next door?

Turns out this rugged terrain would be a big issue.

Mountains are not particularly good because you get non -uniform pressure

gradients underground.

Best place for what we're doing is sort of flat.

sedimentary terrain, which is probably two -thirds of North America.

Ideally, the best place for us to start is someplace where there's been an oil

and gas business, so we kind of know what the rocks are like underground.

So, geomechanical pumped storage won't work here.

But there's another new energy storage solution that could blow pumped

hydropower out of the water.

Lithium -ion batteries.

That's right. The same tech that keeps your smartphone charged may someday

entire cities.

Large -scale battery plants are currently under construction in New

Florida, and California.

Lithium batteries have the potential to lose less power, and they're expected to

get up to the 95 % retention of power.

So could we just build a battery farm to store the excess power from the Hoover

Dam? There's the cost of building the battery that's large enough, but then

there's also how long does that asset last?

If we're looking at things like large -scale lithium -ion batteries, maybe

would be more like a 10 -year period, at which time you would have to deal with

disposal and replacement of those batteries.

For longevity.

Lithium -ion can't hold a candle to the Hoover Dam's good old -fashioned hydro.

Pump storage, the infrastructure itself could last for 100 years or more. It's

something that's going to be around for generations.

If our clean battery can add another century to Hoover's life, it's going to

a good investment.

That would be actually a very useful project.

It represents a titanic amount of energy, so it's hard to duplicate that.

it's worth doing.

The experts agree.

If renewables are ever going to replace fossil fuels, we need as much energy

storage as possible.

We have a lot of challenges in terms of moving into the future, and part of that

is thinking how we can take what we have right now and repurpose it in a more

sustainable way.

We can improve the efficiency by using the most modern technology.

What we do is we bring in the most modern turbines, generators, operating

systems, and then the software and actuators for automation.

So we'll start at 80 % energy efficiency, but aim for 90 % in the next

Now we've got to figure out how long it'd take and how many people we'd need,

if. We built it today.

We're on the Nevada and Arizona border, imagining how we could transform the

Hoover Dam into a clean battery to store renewable energy.

It'd be a huge job, but we think we could build an energy storage project

hundred -year lifespan.

But how long would it take?

And how many people will we need?

To answer those questions, let's flash all the way back to the

1930s, when the greatest engineering project of the 20th century rewrote the

rules of dam building forever.

The idea of sending thousands of people to the middle of nowhere,

To build a dam, essentially in the desert, was a radical idea.

The construction site would have been a fascinating place.

Truly a melting pot of people from every different walk of life.

21 ,000 laborers worked on the Hoover Dam.

And not only did they build a dam, they built an entire city, too.

Boulder City came out of providing housing for these workers who had

been in a shantytown, and this whole city grew out of that.

Today, the population of Boulder City is about 15 ,000, or just over two -thirds

of the 21 ,000 people who built the Hoover Dam in the middle of the Great

Depression. It took that massive workforce two years.

just to drill the tunnels and build the temporary dams needed to prepare the job

site. But the greatest achievement was pouring nearly 800 billion gallons of

concrete in less than two years.

A dam that large, that immense, it was going to take 125 years for the concrete

necessary to harden.

Concrete sets, it gets very warm, and in a structure the size of the Hoover Dam,

It becomes so hot that it can even start fires.

The solution, which the jam's designer came up with, was 230 separate wooden

molds, boxes five feet deep, into which they poured the concrete. In the boxes

were thermometers and one -inch thick pipes, 582 miles of these little pipes.

into which they pumped cold water to cool the concrete so it could harden

gradually and not split apart.

And it's gone unhardening.

A handful taken of the dam in 1995 showed that it was still getting harder.

probably will be decades, maybe hundreds of years before the dam is at its

hardest. The dam was completed in 1936, just five years after

construction began.

The life of a laborer was not easy, and yet they got the project done in a

record time, on a record scale, because of a drive to invent something new.

So, how long would it take us to get the job done?

To retrofit the Hoover Dam for a pump source facility with all the

and regulatory processes required, it could take up to a decade before

construction even begins.

Working out the downstream impacts of water use could be a permitting process

that takes several years.

So let's say it'll take 15 years, a decade to work out the environmental

and another five years to build it.

But how many people will we need?

To retrofit the Hoover Dam for a pumped storage facility, it would take

thousands of people, and likely equal parts lawyers and construction workers.

Let's put the number at 2 ,100.

10 % of the workforce that built the Hoover Dam 90 years ago.

But how are we going to put it all together?

It would be a big challenge in constructing the overall pump storage

using Hoover Dam. The tunnels are key.

At the time of its construction, the Hoover Dam was the most expensive

engineering project in history.

And that was nearly a century ago.

Cost about $49 million to build the Hoover Dam when it was built, or about

million in today's money. It's inconceivable that it would cost that

build it today.

So exactly how much cash is this Hoover Dam retrofit going to vacuum up if

we built it today?

So, you want to turn the Hoover Dam into a clean battery.

What would it take?

We're imagining a pumped hydro plant to take water from downstream and divert it

back into the Lake Mead Reservoir.

It's going to take 2 ,100 workers 15 years to complete.

But it'll last for at least a century.

So, where do we start?

What I would do is I would leave the turbines in place because it's a great

facility. It would be tricky to retrofit the turbine room at the bottom of the

dam. So I would go down to Lake Mojave and put in a pump there and then pump

water back up to the lake. It's about 30 miles away, so you need a bit of a

pipeline.

Transporting water 30 miles between Lake Mojave and Lake Mead is the biggest and

most challenging part of the job.

a significant effort to construct a tunnel.

Today, we could burrow through the desert ground using a specialized

known as horizontal directional drilling.

Here's how it works.

First, a small pilot hole is drilled below the ground, marking the path of

pipeway.

Next, a larger drill head called a reamer is installed.

and pulled back through the pilot hole, carving the tunnel to the appropriate

length. Then, the tunnel is lined with hollow tubes.

Once the pipeline's done, we'll build a pumping station to draw water from Lake

Mojave and send it back behind the Hoover Dam.

But we're not done yet.

Once we have overcome identifying the body of water and connecting the tubes,

The third point will be how much alternative energy or other renewable

the system exists that can be brought to over them.

If this is ever going to become the world's greatest clean battery, it needs

be rechargeable.

As we try to decarbonize the economy, a big part will be to try to decarbonize

the power system.

A lot of how that's done today requires the use of solar energy and wind energy,

which isn't available all the time. So we need energy storage to store the

energy when solar is shining and wind is blowing and then discharge that energy

back onto the grid when it's not windy or it's not sunny outside.

What if we built a world record -breaking solar farm right here?

The Hoover Dam sees about 4 ,000 hours of sunshine per year, over 30 %

higher than the international average.

We could also use solar panels to help out with a major evaporation problem at

Lake Mead, which is 12 stories lower than it was in the year 2000.

There are technologies that exist today that can mitigate some of the

evaporation issues.

There are solar panels that float that can be used, and that reduces

evaporation, also produces additional electricity.

If we could install 3 ,000 megawatts of generating capacity, it'd be the most

powerful solar plant on Earth, surrounding the greatest dam of all

time.

Imagine that.

The Hoover Dam, reinvented as a clean battery to store renewable energy.

It would take 1 ,200 workers to do the job and cut through all the red tape.

But we'd get her done in 15 years.

So, how much would it cost?

This looks like a project that's in the billions of dollars.

But the $3 billion won't include the cost of our solar farm, which, on

costs about $1 million per megawatt. So, building our 3 ,000 -megawatt plant

would cost $3 billion.

We'll budget $3 billion to turn the Hoover Dam into a clean battery, and

$3 billion for our solar farm. Final price tag?

$6 billion.

There's no question that's a hefty chunk of change.

But in the end, the future of wind, solar, and even ocean electricity will

depend on energy storage projects.

Transitioning to a clean energy future is one of the toughest challenges that

have today.

Energy storage plays a critical role to make sure that our grid is not only

clean, but also reliable.

The world of electricity.

is changing before our very eyes.

But the Hoover Dam proved if you get the job done right, you'll always pass the

test of time, standing tall as a reminder of the power we hold to reshape

the future and the high watermark we can achieve if we built it

today.