Speaker 1: Welcome to tech Stuff, a production from iHeartRadio. Hey there,
Speaker 1: and welcome to tech Stuff. I'm your host, jonvan Strickland.
Speaker 1: I'm an executive producer with iHeart Podcasts and how the
Speaker 1: tech are you? So Here in the Southeastern United States,
Speaker 1: a hurricane called Helene has caused catastrophic damage with tragically
Speaker 1: deadly consequences. We here in Atlanta, we were only grazed
Speaker 1: by it. The storm passed largely to our east. But
Speaker 1: even as Helene transformed from hurricane to tropical storm, it
Speaker 1: caused lots of problems, particularly in eastern Tennessee and western
Speaker 1: North Carolina. At one point there were reports that said
Speaker 1: the Walters Dam, also known as the Waterville Dam, had failed.
Speaker 1: While dam is on the Pigeon River at one end
Speaker 1: of Waterville Lake, and it is a hydro electric dam.
Speaker 1: So today I thought I would talk about how hydro
Speaker 1: electric dams work while sending lots of love to the
Speaker 1: folks in western North Carolina and up in Tennessee who
Speaker 1: continue to endure dangerous and difficult circumstances. If any of
Speaker 1: y'all are out that way, please please try and be
Speaker 1: as safe and careful as possible. Fortunately, the reports of
Speaker 1: the dam failing. It turned out to be false, but
Speaker 1: it also meant that people were urged to evacuate, which
Speaker 1: was probably a good thing considering the massive flooding conditions
Speaker 1: that have persisted in those areas. So let's talk about
Speaker 1: hydro electric dams. And there are quite a few things
Speaker 1: we need to talk about before we even get to
Speaker 1: hydro electric dams. One of those our use of water
Speaker 1: power in order to do work that's been going on
Speaker 1: for more than a millennium. The Greeks invented a water
Speaker 1: wheel for doing stuff like milling grain, and early reference
Speaker 1: can actually be found in the works of Philo of Byzantium,
Speaker 1: who lived between two eighty BCE and two twenty BCE.
Speaker 1: It is probably wondering why the heck they were counting
Speaker 1: backwards with their years, that's a joke. Similar engineering was
Speaker 1: going on in China, so it wasn't just the Greeks
Speaker 1: who had thought this up. Chinese engineers had come up
Speaker 1: with similar approaches. So this was kind of spun not spontaneously,
Speaker 1: that's giving the wrong word, but emerging in different parts
Speaker 1: of the world around the same time period. And folks
Speaker 1: had figured out that the flow of water was a
Speaker 1: really good source of work power if you could harness
Speaker 1: that water properly, and water wheels were the way to go.
Speaker 1: This early work would evolve over time, with mills and
Speaker 1: such becoming much more complex over the following centuries, but
Speaker 1: that it's an important thing to start with, this idea
Speaker 1: of harnessing the power of moving water. You typically would
Speaker 1: have a wheel outfitted with blades. The water would make
Speaker 1: contact with those blades, pushing the wheel to rotate, and
Speaker 1: you would use that rotational energy to operate something like
Speaker 1: the grindstone for a mill, so you could grind grain
Speaker 1: down into flour, that kind of thing. That wasn't the
Speaker 1: only application, but it was a common one. So that
Speaker 1: sets the stage for part of our equation. Now let's
Speaker 1: skip way ahead to the early to mid seventeen hundreds,
Speaker 1: so more than a millennia has passed at this point
Speaker 1: from the original water wheels. In the mid seventeen hundreds,
Speaker 1: a French engineer named Bernard Forrest de Belldor wrote an
Speaker 1: exhaustive treatment on hydraulics, and it was titled Architecture hydra Leik.
Speaker 1: It was published in four volumes starting in seventeen thirty seven,
Speaker 1: with the fourth one, publishing in seventeen fifty three. His
Speaker 1: work would help inform countless other engineers who are working
Speaker 1: on things like waterways and water works that sort of stuff.
Speaker 1: Because Old Bernie he was primarily a military and civic engineer.
Speaker 1: Much of his work focused on military operations, which obviously
Speaker 1: require a lot of versatility and resilience. I mean, if
Speaker 1: you're going to make stuff for the military, it has
Speaker 1: to be able to withstand a lot of punishment. And
Speaker 1: his work actually helped set the foundation for the Industrial Revolution.
Speaker 1: It guided a lot of mechanical engineers in the eighteenth
Speaker 1: and nineteenth centuries. Now we'll do another short hop to
Speaker 1: the end of the eighteenth century. That's when Michael Faraday
Speaker 1: was born. He was born in England on September twenty second,
Speaker 1: seventeen ninety one. This was about thirty years after Old
Speaker 1: Bernie had shuffled off the mortal coil. Faraday grew up
Speaker 1: to be a very very clever, smarty pants. Initially he
Speaker 1: was a chemist and a darned good one, but he
Speaker 1: also did pioneering work in the fields of magnetism and electricity,
Speaker 1: sometimes literally as and he literally did work in magnetic
Speaker 1: and electrical fields because I'm clever, and it was Faraday
Speaker 1: who proved there was a relationship between magnetism and electricity.
Speaker 1: If you were to move a permanent magnet near an
Speaker 1: electrical conductor, then you would induce voltage. You would induce
Speaker 1: an electric current to flow through that conductive material. The
Speaker 1: magnetism was what was doing it, but it only happened
Speaker 1: as a conductor moved through a magnetic field. If you
Speaker 1: just put a permanent magnet, even a really strong permanent magnet,
Speaker 1: next to a conductor, then once that initial fluctuation settled,
Speaker 1: you would not have an electrical charge. It just wouldn't
Speaker 1: be flowing. However, if you did keep the magnet moving
Speaker 1: around the or you move to conductor around a magnet, voila,
Speaker 1: you would start to detect an electrical charge. Thus, Faraday
Speaker 1: learned that a fluctuating magnetic field can induce electricity to
Speaker 1: flow through a conductive material. This allowed for the creation
Speaker 1: of both electric motors, which use an electric charge and
Speaker 1: magnetism to convert that into physical work, and the dynamo,
Speaker 1: which does the inverse. You do physical work and you
Speaker 1: use magnetism and you generate electricity through the process. Essentially
Speaker 1: the way This works is you start with a permanent
Speaker 1: magnet and you use this permanent magnet to essentially surround
Speaker 1: a loop of wire in the magnetic field. The loop
Speaker 1: of wire you would mount on an axle that you
Speaker 1: could rotate, and the ends of the wire themselves they
Speaker 1: would connect to what are called slip rings, one each,
Speaker 1: So one end of the loop is on one slippering,
Speaker 1: the other end of the loop is on another slipper,
Speaker 1: both of which are around this axle that rotates. So
Speaker 1: then imagine that you have connecting to the slooper rings
Speaker 1: brushes that in turn connect to electrical wires. So the
Speaker 1: brushes can conduct electricity as well. They just rest against
Speaker 1: the slip ring. So those electrical wires then connect to
Speaker 1: a circuit. Let's say that our circuit connects to a
Speaker 1: light bulb. It's a really simple electrical circuit. So one
Speaker 1: end connects to the slipperings that in turn are connected
Speaker 1: to either end of a loop inside this permanent magnet,
Speaker 1: and the other ends connect to the electrodes on a
Speaker 1: light bulb. So rotating this loop of wire inside the
Speaker 1: permanent magnet means that the loop is going through the
Speaker 1: magnet's magnetic field. And that is the same as having
Speaker 1: a fluctuating magnetic field. So it induces an electrical charge
Speaker 1: to flow in the loop, and electricity flows through the
Speaker 1: slipp rings, through the brushes to the wires, and you
Speaker 1: have yourself a simple electrical generator. So in this case,
Speaker 1: the generator is connected to the light bulb and it
Speaker 1: lights up as current is supplied to it. Now, this
Speaker 1: particular arrangement would be an AC generator alternating current. Now
Speaker 1: to understand why, let's think of those two wires that
Speaker 1: we have connected to either ends of the loop through
Speaker 1: these brushes and slipperings. Right, So one wire connected to
Speaker 1: the light bulb to the slippering is wire A. The
Speaker 1: other one we'll call wire B. So wire A effectively
Speaker 1: is connected to one end of this loop, and wire
Speaker 1: B is connected to the other end of the loop. Now,
Speaker 1: imagine we've got this loop of wire nestled between the
Speaker 1: north and south poles of a magnet, and we've frozen time.
Speaker 1: At the moment, it is in rotation, but we've frozen time,
Speaker 1: so everything's frozen, and right now the loop is horizontal
Speaker 1: in reference to the magnets on either side, so it's
Speaker 1: at a ninety degree angle to the magnetic fields. That's
Speaker 1: when the magnetic field is strongest, at least it's most
Speaker 1: strongly affecting the loop. The A side of our loop
Speaker 1: is closest to the north pole of the magnet. The
Speaker 1: B side of our loop is closest to the south pole,
Speaker 1: and we rotate so that side A is moving upward
Speaker 1: with reference to the magnet. Side B is moving downward
Speaker 1: because it's rotating right now. When the loop is vertical
Speaker 1: with reference to the permanent magnet, then we're at the
Speaker 1: weakest point with reference to the magnetic field. But the
Speaker 1: rotation continues. Now side A is moving downward in reference
Speaker 1: to the magnet and the south pole, and side B
Speaker 1: is moving upward toward the north pole. The flow of
Speaker 1: electricity then reverses direction. So every half rotation this happens
Speaker 1: right so as as side A is moving up, electricity
Speaker 1: flows in one direction. As side A starts to move down.
Speaker 1: Once it's completed that half rotation, electricity moves in the
Speaker 1: opposite direction. It is an alternating current, and this happens
Speaker 1: over an over again, So that is a type of
Speaker 1: alternating current. We're going to take a quick break. When
Speaker 1: we come back, I will talk about what you would
Speaker 1: do if you wanted to create a generator that created
Speaker 1: direct current. But first let's take this quick break. Okay,
Speaker 1: So we talked about an alternating current generator, a dynamo
Speaker 1: if you will, how do you create direct current where
Speaker 1: the direction of current remains consistent it doesn't change. Well,
Speaker 1: A lot of smaller electrical generators use this to create
Speaker 1: direct current. It's great for powering lots of devices that
Speaker 1: require direct current. It's not so great for transmitting power
Speaker 1: across great distances. You really need alternating current for that
Speaker 1: if you want to do it without a lot of
Speaker 1: electricity loss along the way, But we'll talk about that
Speaker 1: in a second. So you do this with a device
Speaker 1: called a commutator. That's the important component in a direct
Speaker 1: current generator, and essentially it's a special kind of segmented
Speaker 1: collar that goes around this rotating axle, and the segments
Speaker 1: are insulated from each other, so you can think of
Speaker 1: there being a gap in this collar that separates one
Speaker 1: side from the other. The commutator essentially reverses the reversal.
Speaker 1: So the wires connect to the commutator via brushes, and
Speaker 1: because of the break in the collar, it's almost like
Speaker 1: the wires are switching which side of the loop they're
Speaker 1: connected to. Remember before I was saying wire A and
Speaker 1: wire B to say like wire A is always connected
Speaker 1: to one side of our rotating loop and wire B
Speaker 1: is connected to the other side. But with a commutator,
Speaker 1: technically the wires are switching which side of the loop
Speaker 1: they're connected to with every half rotation. So because the
Speaker 1: wires are effectively swapping electrodes, the actual flow of electricity
Speaker 1: remains in the same direction the whole time. I know
Speaker 1: this is really tricky. It's tricky for me to explain.
Speaker 1: It's tricky to understand without the use of visual aids.
Speaker 1: I highly recommend that if you want to learn more
Speaker 1: about this, just go to YouTube and search how commutators
Speaker 1: work or how direct current generators work. That'll clear stuff
Speaker 1: up because you'll be able to see an illustration and
Speaker 1: understand what I'm talking about here. But it is a
Speaker 1: very clever workaround, Like you're still technically generating alternating current
Speaker 1: if you were just looking at the loop itself, but
Speaker 1: because of this commutator, you end up with direct current
Speaker 1: as your output. The important thing for our discussion is
Speaker 1: that using a coil of conductive wire. Material moving through
Speaker 1: a magnetic field induces electricity to flow. So if you
Speaker 1: have access to a source of physical power so that
Speaker 1: you can rotate this loop of wire, then you can
Speaker 1: generate electricity without expending a lot of effort yourself. Now
Speaker 1: you can have this connected to something like a crank
Speaker 1: or whatever that you physically turn and generate electricity that way.
Speaker 1: I actually have an emergency radio that works in this principle.
Speaker 1: You can crank the radio and it will generate enough
Speaker 1: electricity to power the radio. So if you are in
Speaker 1: an emergency where there's no you know, access to power,
Speaker 1: you can listen to radio signals and find out what's
Speaker 1: going on. A lot of bicycle lamps work in this
Speaker 1: way too. The lamps connect to the actual pedals, the
Speaker 1: pedal system of the bike, and so as you pedal
Speaker 1: the bike, you're also powering the dynamo that provides electricity
Speaker 1: to the lamp so that you can light your way
Speaker 1: if you're riding around in the dark. So if you
Speaker 1: were to offload this physical work to something else, then
Speaker 1: you can generate electricity without having to you know, exhaust
Speaker 1: people in the process. This is how stuff like wind
Speaker 1: power works. How hydro power works. Actually, it's how nuclear
Speaker 1: power works. Nuclear power doesn't do it through water, it
Speaker 1: does it through steam. I guess technically you could say
Speaker 1: water because it's water vapor, but yeah, it generates high
Speaker 1: pressure steam to turn turbines. But you know, hydro power
Speaker 1: just uses flowing water to turn turbines. Wind power obviously
Speaker 1: uses wind to turn turbines, but all of these ultimately
Speaker 1: end up powering electrical generators. So with a hydro electric dam,
Speaker 1: you've got your dam. Your dam blocks the passage of water,
Speaker 1: and you've got essentially a lake that forms on one side,
Speaker 1: and you do allow water to go through the dam,
Speaker 1: otherwise it wouldn't generate electricity for you. But on the
Speaker 1: other side you have your your continuing river. Right, So
Speaker 1: inside the dam itself, you've got channels or pipes where
Speaker 1: you allow water to pass through from an area of
Speaker 1: higher elevation to lower elevation. And what you're doing is
Speaker 1: you're allowing gravity and water to do a whole lot
Speaker 1: of work on your behalf. Now, the difference between the
Speaker 1: area of high elevation and the area of low elevation
Speaker 1: is called the dam's head. The amount of head determines
Speaker 1: sort of the pressure. How much pressure is going through
Speaker 1: this system. So if there's a very small difference in elevation,
Speaker 1: then the pressure is going to be much lower. If
Speaker 1: there's a greater difference, if the water is coming from
Speaker 1: very high and moving to very low elevation, then that
Speaker 1: water's going to be moving at much greater pressure. And
Speaker 1: at the base of this channel or pipe that's in
Speaker 1: the dam, you have a turbine, and a turbine's essentially
Speaker 1: a type of fan with blades that are designed to
Speaker 1: turn when the whole mess of water is flowing through
Speaker 1: the turbine. There are different designs of turbines. We're going
Speaker 1: to talk about those in a moment. So the type
Speaker 1: of turbine you use is typically determined by the kind
Speaker 1: of dam you're building, and the things like how much
Speaker 1: elevation change are you working with, how much pressure is
Speaker 1: going through what sort of flow rate are you looking at,
Speaker 1: like is it going to be a high flow rate
Speaker 1: or low flow rate? All of these things will determine
Speaker 1: which turbine would be best suited for that particular application.
Speaker 1: Because not all turbines work perfectly under all conditions. Some
Speaker 1: are ideal for very specific applications, and you want to
Speaker 1: use the one that's best suited for the way you're working,
Speaker 1: because that's going to be the most efficient means for
Speaker 1: you to generate electricity. Now, you can then take the
Speaker 1: alternating current created by one simple generator, and with the
Speaker 1: use of transformers, you can boost the voltage that is
Speaker 1: output for the purposes of transmitting electricity across long distances.
Speaker 1: Higher voltages transmit through wires with less power loss over
Speaker 1: length of transmission. So typically for transmission, you want to
Speaker 1: boost the voltage up really high if you're going to
Speaker 1: be transmitting that electricity across longer distances. We're talking about
Speaker 1: alternating current here again, Like if it's direct current, you
Speaker 1: typically want to keep your load that is, the thing
Speaker 1: that's using the electricity fairly close to the area of
Speaker 1: creating the electricity in the first place, the power plant
Speaker 1: in other words, But with alternating current, you want to
Speaker 1: up the voltage so that you can push this electricity
Speaker 1: out to where it needs to be, and then you
Speaker 1: would have a secondary transformer on the other end that
Speaker 1: would step down the voltage for the purposes of distributing
Speaker 1: the electricity to power homes and businesses and that kind
Speaker 1: of thing. So you've got transformers on either end, on
Speaker 1: one end to really boost the voltage, on the other
Speaker 1: end to bring the voltage back down. And transformers are
Speaker 1: actually pretty simple. You could argue that they are not
Speaker 1: more than meets the eye. You have essentially two coils
Speaker 1: of wire or cable inside a transformer. Now you also
Speaker 1: have an iron core inside the transformer. The easiest way
Speaker 1: I would use to envision the iron core is think
Speaker 1: about like almost like a picture frame, but it's made
Speaker 1: out of iron. And so you've got a left side
Speaker 1: and a right side of this right on the left
Speaker 1: side you have looped a coil of conductive wire, and
Speaker 1: on the right side you have a different loop of
Speaker 1: conductive wire. Let's say the left side is our primary
Speaker 1: coil or our primary winding. This length is ultimately connected
Speaker 1: to a source of electricity, so our generator. In other words,
Speaker 1: so the incoming electricity goes to the primary winding of
Speaker 1: our transformer. The other side, the other coil, it connects
Speaker 1: to an outgoing path. This is our secondary winding. And
Speaker 1: what happens with the voltage depends upon the difference between
Speaker 1: the number of turns or coils per side of primary
Speaker 1: versus secondary. So let's say we want to step up
Speaker 1: the voltage. We've got electricity coming from our generator. We
Speaker 1: want to step up the voltage so that we can
Speaker 1: push electricity across miles and miles and miles of cable.
Speaker 1: So to step it up, we have the electricity pass
Speaker 1: through the primary winding wrapped around this iron core, and
Speaker 1: the secondary winding. We have double the number of turns
Speaker 1: that the primary winding has. So let's say the primary
Speaker 1: winding has you know, twenty loops around the iron core.
Speaker 1: The secondary winding has forty loops wrapped around the iron core.
Speaker 1: And as alternating current electricity flows through the primary winding,
Speaker 1: it generates a magnetic field. This magnetic field is also
Speaker 1: guided by that shared iron core, and the magnetic field
Speaker 1: is also fluctuating because we're talking about alternating current, right,
Speaker 1: The current itself is changing directions many times a second,
Speaker 1: which means the magnetic field essentially is doing little flippy
Speaker 1: flops many times a second. And our secondary set of
Speaker 1: turns or coils, remember it has twice as many as
Speaker 1: the primary. It's within range of this fluctuating magnetic field
Speaker 1: that's guided by the iron core, and that means we
Speaker 1: have another case of induction. It is inducing electric charge
Speaker 1: in the secondary windings, and because there are more turns
Speaker 1: in this winding, it's stepping up the voltage. We get
Speaker 1: more voltage coming out than we did going in because
Speaker 1: of this relationship between the number of turns or coils
Speaker 1: in the two windings. So we zap electricity across miles
Speaker 1: and miles of cable. Because voltage is kind of like pressure,
Speaker 1: so the higher the voltage, the stronger the push is.
Speaker 1: Now the other end of those miles of cable, we
Speaker 1: have another transformer, only this one has a secondary coil
Speaker 1: or secondary winding that has fewer turns or loops than
Speaker 1: our primary winding does. So, once again, the fluctuating magnetic
Speaker 1: field generated by the primary coil induces an electric charge
Speaker 1: in the secondary coil. But because there are fewer loops
Speaker 1: in this secondary coil, we have a step down in voltage.
Speaker 1: Now that's the bare basics of electrical transformers. There is
Speaker 1: more to it than that. That gets more complicated. So
Speaker 1: I guess you could argue that, yes, there is more
Speaker 1: than meets the eye, but it's good enough for our
Speaker 1: purposes of this episode. All Right, Now we're going to
Speaker 1: take another quick break. When we come back, I'm going
Speaker 1: to talk about the evolution of turbines and which turbine
Speaker 1: is best used for a power generation scenario, and then
Speaker 1: we'll conclude with a little more talk about hydroelectric power
Speaker 1: and where that really got started. But first let's take
Speaker 1: another quick break. Okay, we're going back to turbines. So
Speaker 1: there is a long history of engineering for these things
Speaker 1: as well. A nineteenth century French engineer named ben wa
Speaker 1: fournee a Ron, whose name I have totally butchered, developed
Speaker 1: a turbine that was based on a water wheel design
Speaker 1: created by his former instructor Claude Burden. As the Encyclopedia
Speaker 1: Britannica puts it, in eighteen twenty seven, ben Wah built
Speaker 1: quote a small six horsepower unit in which water was
Speaker 1: directed outward from a central source onto blades or veins
Speaker 1: set at angles in a rotor end. Quote. He called
Speaker 1: it a turbine, and we would continue you tweaking his
Speaker 1: design to create more efficient powerful water wheels. Now, initially
Speaker 1: these were not used as hydroelectric power generators. They were
Speaker 1: instead used to do physical work for industrial purposes such
Speaker 1: as milling grain. However, much later at the end of
Speaker 1: the nineteenth century, his designs would be used in some
Speaker 1: hydroelectric dams, namely the American side of Niagara Falls in
Speaker 1: eighteen ninety five. In eighteen forty nine, however, an American
Speaker 1: engineer named James Francis created a turbine designed that would
Speaker 1: later be known as the Francis turbine. These turbines work
Speaker 1: well if they're either in horizontal or vertical alignment, so
Speaker 1: they're pretty versatile. They're also good for medium to large
Speaker 1: scale hydroelectric operations, and it's what I would call a
Speaker 1: semi reaction turbine. So there are different types of turbines.
Speaker 1: Some are called impulse turbines. Impulse turbines work from water
Speaker 1: forcing the turbine to turn. It's the force of impact
Speaker 1: of water against turbine that causes rotation. Those are impulse turbines.
Speaker 1: Reaction turbines depend on something else like water pressure, where
Speaker 1: the design of the fan blades in the turbine means
Speaker 1: that you have an area of low pressure on one
Speaker 1: side of the blades and high pressure on the other,
Speaker 1: and that difference in pressure causes the turbine to rotate.
Speaker 1: The Francis turbine is kind of a combo between the two.
Speaker 1: So it's turned partly through the force of water hitting
Speaker 1: the blades and partly through this pressure differential. So it's
Speaker 1: a semi reaction turbine, is how. Some people call it
Speaker 1: a reaction turbine. Some say, well, it's not a true
Speaker 1: reaction turbine. So that's kind of where I get wishy
Speaker 1: washing called semi reaction turbine. But yeah, that area of
Speaker 1: low pressure on one side and high pressure on the
Speaker 1: other is part of the reason this turbine turns. Also,
Speaker 1: incoming water is direc acted inward toward the center of
Speaker 1: the turbine, so the water enters radially. So water is
Speaker 1: entering from around the turbine, around the circumference of the turbine,
Speaker 1: if you will, but it flows out axially, meaning the
Speaker 1: water is ejected in parallel to the axis of the
Speaker 1: turbine's rotation. And these turbines make up more than half
Speaker 1: of the kinds used in hydroelectric dams today. They're kind
Speaker 1: of like the Goldilocks of turbines. They're good for dams
Speaker 1: that are in the middle spot, the sweet spot. Lester
Speaker 1: Allen Pelton created his own turbine in the eighteen seventies,
Speaker 1: so this is after Francis has created the Francis turbine.
Speaker 1: This one we call the Pelton wheel and it kind
Speaker 1: of makes me think of like a ferris wheel or
Speaker 1: a vertical water wheel. It works best for hydroelectric facilities
Speaker 1: that have a high head, so a high difference in
Speaker 1: elevation between where the water is retained and where the
Speaker 1: water is allowed to go. So you want high head
Speaker 1: but low flow rate. And so you want a large
Speaker 1: difference in that elevation but a low flow rate. That's
Speaker 1: where the Pelton wheel has a sweet spot. It is
Speaker 1: a pure impulse turbine, so again this is the type
Speaker 1: that turns because the force of water pushes against it
Speaker 1: and that causes rotation. That's another type that's used in
Speaker 1: some hydroelectric facilities. Then in the early nineteen hundreds there
Speaker 1: was an Austrian engineer named Victor Kaplan who developed the
Speaker 1: Kaplan turbine. This is another This one's our reaction turbine.
Speaker 1: So again this one's good for actually high flow rate
Speaker 1: but low head, so low difference in elevation between the
Speaker 1: retaining water and the flowing water, right, and but high
Speaker 1: rate of flow, so that's good for those operations. The
Speaker 1: Pelton wheel is good for low flow, high head, high
Speaker 1: changes in elevation, and the Francis turbine is the sweet
Speaker 1: spot between the two. Now again, originally these turbines were
Speaker 1: used to do a lot of other stuff rather than
Speaker 1: just generate electricity. They were used to conduct like physical work.
Speaker 1: The first hydroelectric application I can find was in eighteen
Speaker 1: seventy eight. So again, some of these turbines had been
Speaker 1: invented and put into use for decades by the time
Speaker 1: we get to eighteen seventy eight, so they were not
Speaker 1: being used to generate electricity. They were being used to
Speaker 1: mill grain or operate heavy hammers, that kind of stuff.
Speaker 1: In eighteen seventy eight you had a case where someone
Speaker 1: actually used water and a water wheel to generate electricity
Speaker 1: to power a lamp. It was kind of like a
Speaker 1: proof of concept. This was in Rothbury, Northumberland, an a
Speaker 1: massive Victorian house. They call it a house. I think
Speaker 1: of it as like a mansion. I look at pictures
Speaker 1: of this place and it's just it's so huge. It
Speaker 1: even as a name. It's Cragside is the name, because
Speaker 1: the English they love to name their houses. So yeah,
Speaker 1: this one was called Cragside still is called Cragside, and
Speaker 1: this one was owned by a hoity toity, Not no
Speaker 1: big surprise, because again it's an enormous house. So in
Speaker 1: eighteen seventy eight there was this feller named William Armstrong.
Speaker 1: Not just a feller, he was Baron. Baron Armstrong. He
Speaker 1: figured he would make use of hydraulic power to provide
Speaker 1: the kinetic energy necessary to operate an electrical generator, and
Speaker 1: this generator in turn would provide an electrical current to
Speaker 1: a lamp inside Cragside itself, And so Cragside had a
Speaker 1: lamp that depended upon hydropower. Armstrong apparently later used hydro
Speaker 1: power to provide electricity for some other stuff, including an
Speaker 1: electrical rotisseriy. So he was a man after my own heart,
Speaker 1: or at least stomach. In eighteen eighty two, in Wisconsin,
Speaker 1: here in the good old us of A, the Fox
Speaker 1: River became the site of the Vulcan Street Plant. This
Speaker 1: was a small hydro electric facility that used a water
Speaker 1: wheel to harness the power of the Fox River and
Speaker 1: create electricity for a couple of paper mills as well
Speaker 1: as a nearby home. Who's home, Well that would be HJ. Rogers.
Speaker 1: So who was HJ. Rogers? Well, if you guess that
Speaker 1: it was the dude who ran the paper mills, you
Speaker 1: would be right. So the water wheel worked and after
Speaker 1: some tweaking, it worked well. Originally it didn't work at all.
Speaker 1: It didn't manage to light the lamps, but they did
Speaker 1: fix that problem. However, even when it was working well,
Speaker 1: it didn't provide steady, reliable electricity because the flow of
Speaker 1: the river wasn't constant or consistent. So the voltage varied
Speaker 1: with the amount of flow going through the river, and
Speaker 1: it wasn't always safe to use that electricity. Sometimes, if
Speaker 1: the river was pushing pretty hard, you could end up
Speaker 1: with short circuits, which can be pretty risky. But the floodgates,
Speaker 1: so to speak, were open at that point, and soon
Speaker 1: hydro power plants began to take shape along various rivers.
Speaker 1: Lots of lake began to take shape too, because engineers
Speaker 1: were building dams for the purposes of harnessing this hydro
Speaker 1: electric power. So, for example, here in my home state
Speaker 1: of Georgia, there are no natural lakes in the state.
Speaker 1: Every single lake in Georgia was man made, created by
Speaker 1: damming up rivers for the purposes of generating hydro power.
Speaker 1: I grew up not far from Lake Lanier, which is
Speaker 1: a fairly famous one, largely because a lot of communities
Speaker 1: were destroyed through the creation of that lake. Like there
Speaker 1: are urban legends to this day of ghost towns beneath
Speaker 1: the waters of Lake Lanier, where the only inhabitants are
Speaker 1: the spirits of the dead and enormous catfish, Like there's
Speaker 1: always stories about almost supernaturally large catfish in Lake Lanier. Anyway,
Speaker 1: Lake Laneer exists because the beaver dam and we needed
Speaker 1: to create a way to generate electricity. But that's the
Speaker 1: case with every lake in the state of Georgia. Now, globally,
Speaker 1: hydropower makes up about half of all electricity that's generated
Speaker 1: from renewable sources. That's different than saying it's half of
Speaker 1: all electricity. It's not. It's just if we take renewable
Speaker 1: sources as its own pie, the slice that belongs to
Speaker 1: hydropower is about half of that pie. Here in the
Speaker 1: United States a little less than that, it's more like
Speaker 1: forty percent. If we look at overall electricity production, then
Speaker 1: it shrinks down to seven percent for the United states,
Speaker 1: because now we're looking at not just renewable sources, we're
Speaker 1: looking at things like you know, natural gas and that
Speaker 1: kind of stuff. Interestingly, one way that we use hydropower
Speaker 1: today is to supplement other types of renewable energy by
Speaker 1: creating a kind of water battery. So here's how it works.
Speaker 1: You have a pair of reservoirs. You have one reservoir
Speaker 1: that's at a higher elevation than the other, and you
Speaker 1: keep water in the upper reservoir until you need it.
Speaker 1: So that's your power storage, that's your battery bank. When
Speaker 1: the grid needs more electricity than what you can provide
Speaker 1: through other sources, like let's say it's wind power. Let's
Speaker 1: say you've got a wind farm, but there's just very
Speaker 1: little wind blowing, and meanwhile the electrical grid requires more
Speaker 1: electricity than the wind farm can provide. Well, then you
Speaker 1: can open up the gates in that upper reservoir so
Speaker 1: that water flows through a channel or a pipe at
Speaker 1: the base of which you have a turbine. This ends
Speaker 1: up turning the turbine generating electricity. Use that electricity to
Speaker 1: supplement what the wind farm is supplying and meet the
Speaker 1: needs of the power grid. But let's say you're in
Speaker 1: a row of windy days and the wind farm is
Speaker 1: generating more electricity than what the grid actually needs. Well,
Speaker 1: then you would use the excess electricity to pump the
Speaker 1: water in the lower reservoir back into the upper reservoir. Right,
Speaker 1: you have to expend energy to get the water back
Speaker 1: into the upper one. You're recharging the battery in other words,
Speaker 1: so the water goes back up to the upper reservoir
Speaker 1: where it sits until it's needed the next time. So
Speaker 1: when you are switching to renewable sources of energy, because
Speaker 1: so many of them are dependent upon factors that are
Speaker 1: not always present, Like you know, solar power requires sunlight,
Speaker 1: when power requires wind, and there's a real worry that
Speaker 1: what happens if you go without wind for a while
Speaker 1: or it's a really overcast time of year. That's when
Speaker 1: you would make use of things like this, where you
Speaker 1: have power stored in the form of water sitting in
Speaker 1: a reservoir that can then be released into a lower reservoir,
Speaker 1: turning a turbine in the process generating electricity very clever
Speaker 1: as long as you know conditions allow for the return
Speaker 1: of a normal set where you're back to depending on
Speaker 1: wind or solar or accommodation of the two, or even
Speaker 1: something else. And meanwhile, you can pump the water back
Speaker 1: up into the upper reservoir for the next time you
Speaker 1: need it. So there you go. That's a quick rundown
Speaker 1: on hydro electricity how that works. If you ever get
Speaker 1: a chance to tour a hydro electric facility, I recommend
Speaker 1: doing it. They're very fascinating. Hoover Dam is one of
Speaker 1: the ones that has one of the most famous tours
Speaker 1: here in the United States. It's one I have yet
Speaker 1: to go on. My partner has gone on it, and
Speaker 1: she tells me that it was fascinating, and she's not
Speaker 1: a techie engineering kind of person, so the fact that
Speaker 1: she found it really fascinating tells me that that's a
Speaker 1: darn good tour and I need to take it. It's sad that,
Speaker 1: out of all the times I've headed out toward Las Vegas,
Speaker 1: I've never actually taken the time to do a side
Speaker 1: trip over to the Hoover Dam. So I'm gonna have
Speaker 1: to do that in the not too distant future. Anyway, Again,
Speaker 1: if you happen to have been in the path of
Speaker 1: Helene while that storm was just raging, across the Southeast.
Speaker 1: I hope you and all those you love are safe
Speaker 1: and healthy. Please be careful out there. Show love to
Speaker 1: those who have been affected by this kind of thing.
Speaker 1: It has been absolutely devastating for so many communities. And
Speaker 1: pay attention, like just to the communities around your area.
Speaker 1: I think showing compassion and critical thinking is always important,
Speaker 1: but it's particularly important in trying times where people are
Speaker 1: at a real disadvantage. I hope all of you are
Speaker 1: doing well, and I will talk to you again really soon.
Speaker 1: Tech Stuff is an iHeartRadio production. For more podcasts from iHeartRadio,
Speaker 1: visit the iHeartRadio app, Apple Podcasts, or wherever you listen
Speaker 1: to your favorite shows.