I know that Niagara Falls (for example) produces a huge amount of energy, which we use for various…things that need energy. 🙂 And I assume “use” also includes capturing it somehow, as well as storage and transport. But how does that work? What do we actually do to accomplish all that?
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Not quite sure if I got the essence of your question, but I think you mean, how does one generate energy. At its core it’s always a magnet rotating in a spool of conductive wire. The only thing that’s different in every type of power plant is how you get the magnet to spin. In coal or gas planty you burn something und with this heat turn water into steam, which is forced through a turbine, turning the magnet. Nuclear plants use the heat from radioactive decay to make steam and hydroplants (as in you question) move the magnet with the water stream, just like a watermill.
To understand energy you must understand the concept of work.
Work is a force applied on an object that causes it to move. For example, if I push with 1 newton of force on a object and cause it to move 1 meter, I have done work.
Energy is a quantity associated with work. In the above example, there is 1 Joule of energy. It took 1 joule of energy to push on the object with 1 Newton of force for 1 meter.
Energy cannot be created or destroyed but it can be changed into many forms.
We can never use 100 percent of energy for useful work.
There is a huge hydroelectric powerplant there. A large part of the water is redirected to a special kind of turbine (basically a small nozzle shooting a high pressure jet of water onto a wheel that starts turning)
That turns a shaft connected to a generator that produces electrical energy. It’s then transported via power lines just like from any regular powerplant
The source of energy here is just the height of the water. Things high up have potential energy that is released when they fall down.
You can’t actually produce energy – you can just change its’ form.
Sorry for being a smart-arse!
So, I perceive that there are 2 questions that youre asking.
1. What *is* energy, intuitively
2. How do we extract it from waterfalls and use it.
The first one is very hard, the second one is pretty easy.
To start on question 1, energy is just, kind of, the ability to do stuff. We have a (seemingly) finite amount of it since we have more or less proven that it can’t be created or destroyed – please don’t ask me where it all came from in the first place, we’re not 100% sure. But its here! And we can use it!
To use it, we have to store it though, since we cant just make it wherever we want to use it. Making it would be doing something, which requires energy! Chicken and the egg and all that. So, we find something that already has some stored, and we grab some of that. Getting it usually takes some energy, but as long as we use less to get to it than we take out of the “storage container,” its worth it.
Energy can be stored as heat (Thermal Energy), it can be stored as motion (Kinetic Energy), it can be stored as chemical bonds in molecules (Chemical Energy), iy can be stored as electric charge (Electrical Energy) and it can even be stored as simply as stuff being up high (Gravitational Energy). Obviously there are more ways to store energy, but this is ELI5.
Now earlier I mentioned that energy cant be created or destroyed. It can, however, change forms. When you eat, your body breaks the chemical bonds in the food and turns them into movement in your muscles! (Chemical Energy -> Kinetic Energy). When you run up a hill, you can fall down it, and you used that food energy to even be able to run. Plus, you get hot and sweaty from the exercise. (Chemical -> Kinetic + Thermal -> Gravitational).
We use the fact that you can convert one type of energy to another to *do* everything. As I said at the start, energy is just… the ability to ***do.***
So for Niagara (and other waterfall power plants) we have to get the energy from the waterfall to use it. The waterfall is actually converting energy on its own. It takes Gravitational Energy, from all that water being so high up, and converts it to Kinetic Energy, since the water is moving fast at the bottom. I’ll come back to this shortly.
The way that we get energy to our homes is often as Electrical Energy, since moving that is relatively easy – all you *need* for that is a wire, and more Electrical Energy on one side than the other, but now, we have to get the waterfall’s energy to become Electrical Energy.
The way we do that is complex, but we start by making something spin. We use something called a turbine, which you can think of as a fancy waterwheel. We flow water over it, and it spins! We (us and the waterfall, together) have now converted Gravitational Energy and Kinetic Energy to a different kind of Kinetic Energy.
Now, you know that when you put electricity (Electrical Energy) into an electric motor, the motor spins. The how is not important right now, just that it does. Now, that works in reverse too. We can just make the motor spin using that Kinetic Energy that we just got from our turbine, and the motor will convert that to Electrical Energy! One step away from energy in our homes!
A little while ago, I said that the only thing we need to transport Electrical Energy is a wire, and more energy on one side than the other. Well, we have a lot of energy here at the power plant, and not a lot at your house. So, we ran a lot of wires (powerlines) to almost everywhere in the country. Now you can get that Electrical Energy and use it in your house! Every device in your house is just taking that Electrical Energy, and in a bunch of different ways, converting it.
The oven turns it into heat, the lamp turns it in to light, and the stereo turns it into sound. A thousand devices turn it into a thousand things, and it lest each of them… *do,* whatever it is they do.
I can go further in depth if you like, I studied energy (Thermodynamics) a lot in school and obviously like talking about it, but thats about what I think an ELI5 lecture should touch on for the questions I think you wanted to ask.
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