You're now tuned in to electrical theory 101. I'm your instructor, @DanDays - The Luckiest Guy I Know. Today we'll address H₂0 and its significant role in hydroelectric generation and energy storage. If you ever wanted to know how rain makes your house glow at night, welcome! I'll explain it in a way even you understand.

Moisture collects in the air, right? Heat and steam rise yata yata—precipitation. It collects above our heads forming clouds until those clouds are too heavy and are forced to release the water. What goes up must come down and a river is formed.



Rivers naturally create isolated sections capable of generating energy. Waterfalls for example can distribute a lot of force. Unless that force is funneled and controlled however, regardless of its height or mass, the majority of potential is lost due to the elements: temperature, wind, overspray, etc.

Generation

Constructing a wall like Melton Hill Dam in Lenoir City, Tennessee, between two accessible points on a river creates a lake or reservoir restricting the flow of water. Once the river is pooled and confined, the height and mass of the waterfall can be controlled. A controlled waterfall capable of forcing tens of thousands of gallons of water per second is capable of turning anything designed to rotate.

Before the September 11th attacks in New York City, anyone could walk, drive, pedal across dams, most were considered roadways. You could stop along the way and take as many photos as you'd like, too, no questions asked. Not anymore. Now there's fences and signage restricting access to all of the nations dams and controlled waterways. You don't want to get caught paying too much attention to generation systems or anything associated to infrastructure in the US anymore.



That's Melton Hill Dam, what it looks like on the surface. It's a 3-unit generation system, I'll explain why we know that in a minute. Melton is a hydroelectric generation station which means rather than coal or steam, they use gravity and water, the simplest and least expensive sources to produce and provide electricity.

Located on the main floor of the dam will be a control room. Inside the control room will be everything from light switches and control boards to a direct phone line to the White House. The people responsible for surveying and maintaining the system from inside that control room are called operators. Operators communicate directly with Load Dispatchers.

It's the Load Dispatchers responsibility to clear equipment danger and personnel proximity at both receiving stations on either side of Melton Dam prior to energizing or de energizing the dam.



Beginning at or near the surface of Melton Lake and extending (according to Wikipedia) 103 feet under the control room floor are three penstocks—one per unit. Penstocks are those big pipes you see running up and down mountains. As the length of those pipes reach their target, they're funneled in diameter from let's say 50 feet all the way down to about 2 feet creating water pressure powerful enough to energize an entire city's electrical grid.

The three targets are called turbines. Regardless of source; coal, steam, wind or gravity, their concept is identical—rotate 360 degrees with or without mechanical assistance. The only difference is the design. Wind turbines like you see along roadways or in the middle of the ocean are propellers because they're wind generated.

Water generated turbines look more like a paddle wheel you see on the back of old river boats. They're massive and designed specifically to deflect water which causes the turbine to rotate in the same direction as the forced water at too many revolutions to count per second.



Inside the head of those turbines are gears and rotors and bearings and all kinds of components designed to assist a solid, stainless steel cylinder called a shaft as it spins freely. I've constructed and decommissioned hydroelectric units with shafts as big around as a 757 fuselage—transported in sections on five or six semi trucks.

Affixed and balanced to the outer center of the shaft is an armature. Armatures consist of a conductive metal like copper or aluminum wound tightly around the outer center in tight wraps hundreds and thousands of times. Bordering the armature are brushes, their purpose is to confine the energy to the center—brush it back. The armature spins against stationary windings with an adjustable gap between the two surfaces and, as revolutions cycle, inductance is created.

Inductance and inductive reactance, kinetic energy, all of it increasingly builds in those stationary windings until the unit is de energized. The faster it spins, the more it builds. As all of that energy is confined, refined and redistributed, what began as water now creates anywhere between 12 and 500 thousand volts.

Voltage is then routed to a nearby converter station or switchyard where before it's branched out to your community, it's transformed and regulated. Private residences won't survive 500,000 volts, 500kv is for distribution. Stateside homes are rated at 240 volts.

There's both step-up and step-down transformers. A hydroelectric system requires stepping down. From the switchyard to the receiving station in your neighborhood to the transformer on the pole at the end of your driveway, power lines are continuously stepping down to accommodate 240 volts.

From the pole at the driveway to the panel on the side of your home, through each interior wall, on the ceiling, under the counter, behind the television and everywhere else—energy. Tada! Plug in your hair dryer.



On the backside of the dam continues 300 miles of Clinch River. When the station is generating and spinning turbines, the turbine enclosure in use or two or all three will open like a garage door allowing the lake to empty into the river causing it to rise dangerously quick.



Between 10am and 7pm when energy rates are at their peak price, Melton Hills will roll up the doors and open their water valves to max capacity. It's still gravity fed, costs Melton nothing to open the doors and generate when the consumer is contracted to pay premium fees.

Storage

After the sun goes down and the neighborhood's ready to call it a day; lights are out, businesses closed for the night, energy prices are at their lowest. This is the same time the lake level is at its lowest and the river at its highest.



Melton Hills will reverse the turbines during these hours—cheapest rates. They're no longer gravity fed from the lake, now they're mechanical. They'll run those turbines backwards drawing the river water back into the lake above until it rises to capacity. Now it's energy being stored as water.

The following day when energy rates are at peak pricing again, they open the gates again and allow gravity to generate more revenue again. The cycle repeats 24/7 - 365, no holidays or breaks, generate generate generate around the clock because we got phones to charge and alarms to set, microwaves and curling irons to heat stuff up. Lights and porch lights, refrigerator lights and night lights to light stuff up. Water heaters, pressure washers, dishwashers and vanity's to clean stuff up and helicopter communications.