Today, you will discover with us simply the plant that generates the most electricity on our planet, Itaipu Binacional. If you are too lazy to study geography, Itaipu is located in the extreme west of the state of Paraná. This river that we are seeing down here, by chance, is called the Paraná River, and it is on the border between Brazil and Paraguay.
So, Itaipu is a plant that is divided between Brazil and Paraguay, that's why it is called a binational plant. Right now, I'm stepping, for example, into Paraguayan territory, because I'm on this side of the Paraná River. Quickly, how does hydroelectric power generation work?
This dam is filled to the top with water, that's why we say that this water has gravitational potential energy, it's an energy that will be released when the water goes down by gravity. And that's what it's going to do. It's going to go down these pipes and it's going to get down there in a turbine.
This turbine will turn, so the gravitational potential energy is already transformed into kinetic energy, which is the energy of movement, and the turning of the turbine will trigger an electric power generator. The kind we are used to seeing in the Manual do Mundo. And we already have electricity.
That simple. From one end to the other, the Itaipu dam is seven kilometers and 900 meters long. One part of the dam is made of soil, the other part is made of stone and this central part that we are seeing here, which is where it generates energy, is made of concrete.
What we are going to see in this first part of our video is how people do to guarantee that it will never burst and take away the city of Foz do Iguaçu, which is a little further down. Can you see the ground down there? We will get there!
These aren't floors, no. It is the altitude that we are in relation to sea level. We call it quotas, so we are going down to quota 40, 40 meters in relation to sea level.
If we were to compare the height of this gap here with a building, it would be a building with more or less 60 floors. More than that, I think I got the calculation wrong, I didn't count the part of the dam that runs from the water upwards, it's 16 meters. So, it's a 65-storey building.
Cool! The first thing I had no idea is that the dam is all hollow! Almost 200 meters of unevenness here, it's a giant cave.
We went down to the bottom of the dam structure. Here is the bed of the Paraná river, that is, we reached the rock on which the dam was built. Here, we are at count 40, as we are at 220 up there, 180 meters below the level of the dam.
Right now, I'm right down here. You're looking at this whole colossal structure here, it might seem like it's as hard as a rock. It's not like that, no.
These walls move. The entire structure of the dam is made up of one hundred and thirty-seven concrete blocks, which is about 210 times the amount of concrete used to build the Maracanã stadium. You must imagine how big these blocks are, and between them there is a little space, a margin of error there, a joint for them to be able to move independently.
Let's get to know a so-called stretching meter, it measures the displacement of the plates. So, I have a kind of ruler, right? That I make a perfect fit, as if it were a male and female fit, right?
It's a dial indicator and as I open or close it gives me the reading. What is the resolution of the instrument? Micron, millesimal and millimeters.
The association of these three readings allows me to calculate how much this joint opened and closed and how much it moved in that direction. And the ones on the floor, where I do the same three readings, and it gives me the opening again. But then in this movement, I will have the sliding between one block and another.
But does it shift? It shifts. And its movement is seasonal, that is, it opens in winter, closes in summer.
And what is this giant pendulum for? It serves to monitor the movement of the dam, which would be its inclination in relation to itself. This inside, we have a weight of 60 kilos?
60 kilos that is inside that bucket. Here is oil, this oil serves to reduce the vibration so that we have greater precision in our reading. And the line is stuck up there?
Up there. Up in the water? Above the water, at quota 223, more precisely.
As it moves up there, what hangs here gets farther or closer. Exactly a mason's plumb but high tech. Exactly.
And two hundred meters long. And a precision greater than a mason's plumb bob. Any move you make up there, will that line hit the wall?
It is, if it is a sudden action. If it's earthquake We hope not. May it never happen.
So, this here is the equipment we use to take the reading, it's called a coordinometer, it's the reading that takes place at the tip of this cone here, a metallic cone. It is this reading that interests us. There is also another pendulum, only it is inverted, which serves to see if the dam is moving in relation to the ground.
But then the end of that instrument is stuck down there, anchored to the rock, and the other end is on a buoy on top. So if the dam shifts relative to planet Earth, you know. It will be this line that will count.
This guy who will deliver. The dam practically did not slide, from the time of construction until now. How good, huh?
Great, for us it's great! We arrived here in a tunnel that is under the concrete, and the function of this here is to drain the water that infiltrates. It is natural that a little water infiltrates and here they can also measure whether the amount of water that is infiltrating is the right one.
In our structure, you have several points where you know the water will pass, so you give it a preferential path and monitor this water. Monitored gutter! That's what happens with drains.
And if you cover it, you'll open it somewhere else, right? Exactly. If you cover her here, she will look for another preferential path and leave.
One important thing is that all this water needs to be pumped out. it's these pumps behind here that do that, because here we are at a point that is underwater, both in relation to the level of the dam and in relation to the water level that is after the dam. So, there would be no way for this water to leave here.
If we don't pump it, one hour this will all be underwater. We came here through a corner of the dam where there is a special structure called a spillway. A nice thing here is that as it is a binational place, the posters are written in two languages, in Spanish and Portuguese, because part of the workers come from Paraguay.
Now, could you say what "carnet rojo" is? Put it in the comments. I doubt anyone got it right!
At the height of the construction of Itaipu, there were 40,000 people working at the same time, and here in the tunnels they left some graffiti. Take a look at it here. This mule in about 10,000 years or so will be a cave painting.
It's going to be in every textbook in every school. Spillway is an opening that exists on top of the dam that serves to dispose of water that is not being used. If the dam is at the maximum level and we need to throw some water out, we need to release the water here.
But it is gigantic. Up here, it is possible to pass 62 million liters of water. You can see that I walked a lot, and this thing never ends.
Just to compare with the Iguaçu River, for example, which is close, it would be worth 40 times the water that passes through the Iguaçu Falls. Would make a pretty cool waterslide, huh? Sadly this place is closed today.
The normal condition of a spillway is always closed. As we are seeing here. Exactly.
It will be opened in emergency situations or to drain excess water. So, for example, if a tower falls and the machines are forced to stop, there will be water left over. That's it?
Exactly, this water has to be compensated with the opening of the spillway from a certain flow rate. In practice, it is what guarantees the life of the city of Foz do Iguaçu. Exactly.
I'm here on top of the dam and it's down here that the water is captured to move the plant's turbines. We can't see it from here, but under me there are 20 holes, 20 places where water is captured, and their entrance is more or less 600 square meters. Down there there's a grid to keep out logs and things that could damage the plant down there, but I think swimming here is not a good idea, huh?
The water entering the plant is controlled by a set of gates. Each white cylinder you are seeing works like a syringe. When you inject oil, the gate can open or close.
How long does it take to open and close? Opening it takes around 20 minutes, and closing in normal condition in three and a half minutes. It closes faster because it could be a security issue.
This one is one of the wheels that go down the gate, it's a giant roller that weighs just 250 kilos. They are replacing the old carbon steel ones that were rusty with new stainless steel ones. The water that entered at the top of the gate is passing through these pipes here, and only up close can we see that they are gigantic.
The name of it is forced conduct. For you to have an idea of the amount of water that passes here, it is more or less half of the water that goes down through the Iguaçu Falls. You can feel the thing vibrating here, like a car engine running.
Listen the noise. Underneath every white pipe you see there is a turbine and a generator. Half of the plant generates energy for Brazil at 60 hertz and half of the energy produced goes to Paraguay at 50 hertz.
But Brazil buys a good part back. So, we can see the towers going back to Brazil, then this energy has to be converted back to 60 hertz. The cool thing is that these 20 generating units work independently.
And today one is stopped. Guess where we're going now? Let's go down to the powerhouse, which is where the energy is generated.
Here, inside the plant, the noise is very strong, we have to wear ear protectors, and it is almost impossible to talk. I'm here inside a telephone booth, and it has to be acoustically isolated as if it were a studio. I'm going to open the door on this here, and you're going to see the difference.
See if you can hear me right here. See that yellow line down here? It is the border between Brazil and Paraguay.
I'm in Paraguay, I'm in Brazil. This here is the control center, it's like the brain of energy generation here inside the plant. We can see here the machines that have been installed since Itaipu started operating in 1984.
They still work today, but since 2000 there's been a digital system where we can see the data on that big screen back there. We are now going to enter the spiral box, it is a place where the water passes. It is also a place that very few people have access to.
Let's go! Remember that white pipe we saw outside? It leaves right behind me, so when it's full of water, there's half of the Iguaçu Falls going by.
This box helps us to make better use of the power of the water that is coming from up there. The box is made of steel and here we can see the welds, the borders, but it is very polished because a lot of water passes here, it cleans the box as it passes. And this structure that you are seeing does not rotate, it is fixed.
The water will enter here, it will pass through these distribution blades. The first ones are fixed, but further in there is a second set with mobile blades. They will direct the flow of water to keep the turbine turning at a constant speed.
Let's see the turbines! These here are the turbine rotor blades, that is, the water will hit this thing here to make the turbine turn. Here I have a miniature, you can have an idea about the size of this here, because we can't see it up close.
The detail is that the turbine has 300 tons. You must imagine that it is not at all easy to move this here. We will try?
I don't think it works, no. If you could look at this place where I am from the outside, it would have more or less this format here. The water enters through this end, of course it would be hollow and not solid like this one, and it will be distributed to the turbine that would be here in the middle.
After the water moves the turbine, it comes here. It's going to go through those paddles and it would be falling on top of me if it was working. I'm inside the turbine underneath it.
At this point here, the water has already given all of its kinetic energy to the plant. It moved an axis that is connected to this turbine here and this axis is coupled to the generators that are up there. From here on down, the water is returned to the Paraná River.
The turbine is eight meters in diameter and rotates at about 90 revolutions per minute. As you might have guessed, this place here is not a special place for people to walk. This floor, for example, that I'm walking on, it doesn't stay here while the plant is working.
It was put in for maintenance. So, any maintenance that has to be done in here, a whole special structure has to be set up so that people can move around. Here, for example, there is a capsule for someone to go down to the bottom.
It looks like the one who saved the Chilean miners back in the copper mine. And here the person can go down where the water will come out to the river. The galleries of the pyramids in Egypt must be nothing close to this here.
To connect the turbine to the generator, we have this shaft here. It is three meters and 70 in diameter. At the bottom is a turbine, this time a turbine with water running through it, it's not dry as we just saw, and at the top is the generator.
When you place the twenty generators next to each other, they take up quite a bit of space. Looking up close it's a little bigger than you were imagining from up there, go! So, this here is the largest free space that exists inside the dam, we can see each cover corresponds to a generator.
And the total length is one kilometer! The space here is big like that because just imagine if you need to remove one of those turbines that we saw. They will have to come out through these red caps and be taken through an exit by these cranes that we can see here.
Basically, to generate energy we need to pass a magnet near a copper coil. Here inside something similar to that, only a little bigger and more technological, right? Exactly.
The fixed part is composed of the stator busbars or the winding, that is, the copper wires in a motor. Let's say, a comparison. In the moving part, it is the rotor of the generating unit.
That's where the electromagnets are. Here, then, we would have magnets rotating in the center. It would be as if we had magnets running in the middle, and the coils bouncing around.
Exactly. When we talk about a coil, it's not a coil of wires that you don't even have inside your blender, no. It's a coil of these wires here.
Look at its size. Inside the wire there is a space that is for running water for the wire to be cooled from the inside out. People here are correcting me that the thread is so thick that it ceases to be a thread.
He is already a bar. Here you can see the inside, the part that rotates is darker, brown, and outside, in orange, the coils that are wound there. An interesting detail of Itaipu is a gigantic machine where the rotor is practically 16 meters in diameter.
And the difference we have in terms of physical space between the rotating and fixed parts is around 2. 5 centimeters of space. Wow, the finger almost doesn't go there.
Exactly. From Itaipu there are eight transmission lines, but there are twenty generators. And to manage this, inside the dam, there is a substation.
It's like, thinking about a house, it's more or less like that power distribution board that we have. Exactly. So it's the other way around.
There is an entrance and several feeders. Here it would be more or less the same thing. Circuit breakers perform this switching according to the system needs.
The voltage is 500,000 volts, and the breaker's current rating is 4,000 amps. And the interrupting capacity is 63,000 amps, right? The residential circuit breaker is in the 50 amp range.
It's a super ultra mega breaker. Exactly. There are 54 such breakers spread across the substation.
If, for example, a transmission line goes down and you need to cut the transmission and power, is this where you go to disconnect? Yes, actually, this shutdown is automatic. It has a protection system that senses any system disturbance.
When this happens, the beginning of the line and the end of the line are disconnected. The door over here is our rotors over here. Is the place where you release the thread inside here?
Exactly. So much energy passes through that the wires have to be insulated with a special gas. The gas that is used here to insulate the wires is called sulfur hexafluoride, or SF6 for its chemical formula.
One cool thing is that it is much denser than air, it is up to five times denser, and it is a totally inert gas. It doesn't react to practically anything. The issue is physical space.
A conventional substation of this size would have to be two and a half kilometers long and 750 meters wide, that is, it would be ten times bigger. It wouldn't fit in here. So, it would be impossible to have 20 generators of the power, of the voltage that Itaipu has.
And with the gas, you can put one wire very close to the other. In here there are 500 thousand volts and 2000 amps. I can pull over here without risking my safety.
If it was a wire without this protection, how many meters would we have to be away? At least 5 meters away. And even then, we would be feeling the effects of induction.
The hair standing on end. Let me see. Just kidding!
There are two things that make Itaipu so powerful. The first is the unevenness, the difference between the water level up there and the level down here, which is almost 200 meters. This makes the water reach the turbines very hard.
The second thing is the flow of the river, the amount of water coming into the Paraná River. And there is a third interesting factor is that upriver there are 54 plants that can regulate the amount of water that reaches here in Itaipu, ensuring that it is a good flow all year round. And this is where the Itaipu cycle ends.
The water that passed through the turbines, which generated energy, is coming out down there. We can see it reappearing there, forming a bubbling. What is splashing did not come out of the turbine, that is cooling there.
And the electricity, we can see it going down these lines to your house, from where you are watching this video with energy generated here in Itaipu, probably.
