When was the last time you thought about
the origin of the water that comes out of your tap?
For most of us,
gone are the days when we had to spend so many hours
just to transport water.
Now we just open the tap it's there –
it's so obvious.
But we still need huge amounts of energy
to transport the water to our buildings.
Pumps and pipes now do the job for us.
And that process is very, very energy intensive.
In fact, the treatment and transport of water
consumes a staggering 4% of the world's energy.
And its carbon emissions...
rival that of the aviation industry.
So here's the mind-blowing part:
what if I told you that these simple water pipes
have huge untapped energy potential?
They have enough energy to power your house.
In fact, millions of houses around the world.
This is not just a pipe dream.
It is already happening in places like
the US state of Oregon or the Turkish city of Manisa.
So how much power can we harvest from the flow?
Water is the greatest moving mass on Earth,
with huge energy potential.
Hydropower is a cornerstone
of low carbon energy generation.
But dams have become bigger and more controversial.
Yet the water pressure in our pipes goes mostly untapped.
So how does water get to our taps in the first place?
"The conventional water supply system
brings the water from the source and treats it,
delivers it to people in the majority of countries,
comes out of your tap, then it's taken away,
it's treated, then put back in the environment."
This is Newsha Ajami.
She and her team have examined
the research on in-pipe turbine technology.
"This process is very energy intensive.
You need a lot of energy to move water
from location to location, to treat it,
to distribute it among people"
Some cities are lucky,
and their water comes from higher altitudes.
So, gravity does most of the job,
and less energy is needed to transport it.
But in Berlin, London or Delhi, for example,
the water supply system relies on pumps.
And in some countries in the Middle East
the water needs to be desalinated first.
That absorbs 4 times more energy
than conventional water infrastructure.
We also need a strong water flow
so that it doesn't take 10 mins to fill a pot.
If our water doesn't come from reserves at higher altitudes,
we need pumps.
But to stop pipes bursting due to too much water pressure,
we install devices called pressure valves.
They basically remove the excess pressure.
That is where all that juicy energy is wasted.
And where in-pipe technology can come in.
A turbine in the pipe could convert
that excess pressure into electricity.
This is a little water turbine.
We can install this into our existing water infrastructure
that we depend on every day.
The water would rush through this turbine
and it would make it spin like crazy.
And you know what happens when a turbine spins, right?
It generates good old electricity.
In California
20 percent of the state's energy goes into water infrastructure:
pumping it up from the ground,
moving it to different locations, and making it drinkable.
A huge chunk of energy could be recovered
by harvesting the excess pressure.
Lets' find out how this works in principle.
I am setting up a little circuit to connect different gadgets
to harness the electricity generated from this tiny water turbine.
I can charge a battery, run a motor, turn on a light,
and charge my phone with it.
This is of course just a tiny, tiny water turbine.
We can install bigger ones
wherever there is an abundant water flow.
The energy that can be created depends on the turbine
as well as the amount of pressure in the pipes.
"We really don't have a solid number to say
this is how much energy we can generate.
But the reality is – across the world,
the way we have built our water systems,
water is moving from location to location,
and it can potentially be used to generate energy.
So I think the potential is quite high."
Different studies give different estimates.
One report for the US Department of Energy estimates
that in-pipe turbines could produce
1.41 gigawatts of electricity across the US.
That's quite a conservative estimate.
It would be enough to power
at least one million homes in the US,
or more than 10 million in India.
Yes, a house in the US uses 10 times more than one in India –
but that's another story.
Other studies are more optimistic:
Alden Research Lab from the US
says up to 43 gigawatts of energy per year
could be harvested in the state of Massachusetts alone.
Water systems were built a long time ago.
With only one thing in mind:
to deliver water.
So, we haven't got much to go on
when we try to calculate the potential energy within pipes.
Because generating energy was never part of the plan.
That's one reason why the reports differ
over this technology's potential.
"We need to craft our institutions
to be responsible for both water and energy.
So far our energy-generating institutions
are independent of our water supply institutions.
This is Vishwanath Srikantaiah.
He has been working in the water sector in India
for the last 36 years.
"In my city of Bangalore,
65% of the income of the water utility
goes towards paying energy charges.
Water should be transported
95 kilometers and 300 meters high.
So energy is the most important
component of the water price."
If water companies created their own energy
using their infrastructure, the price of water could drop.
Another great piece of news is that
these turbines can be retrofitted
without harming the environment.
"The operators love it.
We are powering EV-charging stations."
This is Gregg Semler.
His company has been charging cars with in-pipe electricity.
How cool is that?
"The biggest challenges that we have is that it's new.
And so, with anything that's new,
people always want to understand
what its impact is on their operation.
But whenever I do a presentation,
or whenever our team is presenting
to people who are knowledgeable about water distribution,
they get it immediately."
Obviously, cost is another thing,
and these new systems are not yet incentivized
in many places.
"People can recover the cost in a couple of years
or in less than decades and that's what we have seen.
Obviously depends on the scale of the project,
as I said, the cost of electricity.
But then again you need to have enough upfront capital
to be able to invest in these systems
and then have time to recover them.
This might be tough for small businesses –
but municipalities and big companies
have a responsibility to step up.
Countries in the Global South have a great advantage
as they are currently expanding their water systems.
India is the world's largest consumer of groundwater,
and most of its cities
don't have constant running water at the moment.
But the country is planning to invest
hundreds of billions of dollars
to provide its huge population with pressurized water 24/7.
"There are exciting and immense possibilities to do that.
That's because we're going to build half of our infrastructure
in the coming 20 years.
India will be urbanizing very fast,
our water supply networks will be expanding very fast
and therefore these opportunities will lend themselves."
Some cities are already on board with this technology.
Take Portland Oregon, for example.
They are harnessing the power of in-pipe water
to light up their streets
and power essential public infrastructure.
And the Eastern Turkish city of Diyarbakir
is already generating 2 million watts of electricity
and selling it to the local grid.
And it doesn't stop there:
San Francisco, Manisa, Cape Town –
they're all catching on to the potential of the untapped energy
flowing beneath their streets.
You could say that in-pipe technology
is an energy hero with a low profile.
It makes the most of what's already in place
while reducing our reliance on fossil fuels.
With zero to very low environmental impact
Of course in-pipe turbines are not going to
decarbonize our whole economy.
But if I managed to charge my phone,
light up the bathroom, turn the fan,
with this little fella –
imagine what we can do on a larger scale.
Tell us what you think in the comments.
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