Electricity, Part Two

AC/DC jokes aside, this is important current information.

AC/DC jokes aside, this is important current information.

So, by now, I assume you have read the previous post, Electricity: Part 1, at least five or six times to really grasp the intricacies of what electricity is and how it relates to the transfer of energy. You may also have read it once, fallen asleep and Google led you back here to part two against your will. Either way, I hope you enjoy the following discussion on the topics of electrical loads, alternating vs. direct current, single phase vs. three phase power, and the generation of electrical energy. Please enjoy it, I’ve lost a lot of sleep working on it. Sorry; that was supposed to be an inner monologue comment.

At this time, I’d like to ask for patience from those who are not big fans of geometry, trigonometry or other forms of mathematics. I’ll try and keep some of these concepts as simple as possible, while trying not to offend the majority of engineers, mathematicians or academics by being partially or even totally wrong. I will also try and keep the electrical jokes to a minimum. This subject is not for everyone so I make no promises.

Circuits

In Part One, I introduced the idea of an electrical circuit. Electrons and the electromagnetic energy they carry will not flow from one pole to another unless their path is fully connected. Flipping a switch in your home either breaks the circuit (literally creates a gap in the wiring), or completes an electrical circuit and allows the flow of electrons. The following images show the simplest of circuits; one with a battery (a power source), wiring (path) and a light bulb, where the flow of current travels from one terminal of the battery, through the wire into the light bulb, causes the bulb’s filament to glow brightly and then continues on through the wiring to the battery’s opposite terminal. The second image is similar to the first, but the power source in this case is an AC Generator, so the flow of electrons change directions at a certain frequency. We will get into the differences between AC and DC later in the discussion.

Direct Current Circuit

AC Current Circuit

Every electrical circuit needs both a power source and something to resist the flow of electrons. Without some resistance, electrons will flow very quickly through a conductor. Given no speed limit (and no fear), drivers on an interstate would drive as fast as they can. If everyone drove like they were qualifying for the Daytona 500, you can imagine how many accidents would occur and the entire transportation system would break down. Electrical current is no different. If permitted, electrons will move as fast as possible in larger numbers and would eventually exceed the wire’s ability to handle the heat generated by the flowing electrons. When this happens, the wire can actually melt or catch its insulation on fire. A common cause for this type of excessive current is a “short circuit” where someone directly connects the two poles of a battery, or when a current carrying conductor (wire) comes in contact with metal objects or people; allowing current to flow unimpeded into them or into the ground. Resistance keeps the flow of electrons in check. For any normally operating circuit, this is not a problem since the entire point of electricity is to supply energy to some kind of device or equipment. The component of a circuit that utilizes the energy being transported and provides some resistance is known as a load.

Loads can be categorized into many different groups, but the most common are resistive, capacitive, and inductive. I know, the terms are beginning to sound complex and you may have started dozing off, but think of them as loads that resist the flow, capture the flow, or induce their own flow of electrons. It’s an over-simplification, but it works for me.

Types of Loads

Resistive

Resistive loads are some of the most commonly known (or thought of), and are characterized by the fact they create heat (and/or light), the voltage and current are in phase with each other (more on phase later), and they do not generate their own magnetic field. Common resistive loads would include incandescent light bulbs and most electric heaters.

Resistive loads take advantage of the fact that some metals are conductive, but put up a fuss when they are energized. Much like a teenager when they are asked to clean their room; they are fully capable of doing so, but they sure put up a lot of resistance to do so, and cause their parents tempers to rise. I know it’s a thin comparison, but as a parent, its painfully relevant.

Certain elements such as Tungsten, used in common incandescent light bulb filaments, and an alloy used in heating elements called Ni-chrome (a mixture of Nickel and Chromium), are conductive, but when electrical current is passed through them, they emit much of the energy as either light, heat or both. Given the fact that only one of these results is typically desired, the balance of the energy used is wasted. This makes resistive loads very simple, but also very inefficient.

Capacitive

Devices used as capacitive loads are commonly referred to as capacitors. I know; big shock (the puns don’t stop here folks). Capacitors are capable of storing an electrical charge that can be released at a desired speed and quantity. Capacitors are not unlike a short-term rechargeable battery, but are used to store a large charge that can be released nearly all at once, or released slowly to provide a more even voltage or current. Although used in nearly every electronic device made today that can plug into an outlet, some better-known examples of devices that heavily rely on capacitors would be camera flash-bulbs, defibrillators and joy buzzers (although the last item is not a very safe or nice use of a capacitor, and no I’m not suppressing painful childhood experiences).

Inductive

Inductive loads can seem more complex, but are one of the essential reasons humans learned how to harness the power of electricity.

As discussed in Part 1 of this post, we learned that passing electrical current through a conductive material creates a magnetic field. In single conductors the field is negligible, but when current is passed through a coil made of some conductive material, a larger magnetic field is created. The exact opposite is also true. If a coil of wire is passed through a magnetic field, it introduces a flow of current in the coil / conductor. Simply put; pass a magnet by a coil you get current in the coil. Energize a coil and you get a magnetic field.

This behavior of inductance is the reason that generators are able to create a flow of electricity and why motors are able to transform electrical energy into mechanical movement. The discussion of inductance is a substantial one on its own, and we could spend hours talking about induced voltage, power factors, and other engineering type stuff, but I’m stopping here. I don’t have the capacitance to go on, so I’m going to focus on how inductance allows for the creation of electricity as we use it in residential and commercial buildings across the world.

I’m a fan of AC/DC, and it’s not just a phase.

tesla-edison

Let’s talk about AC, DC, Edison and Tesla (the man, not the car manufacturer).

Thank you to Maggie Ryan Sandford at mentalfloss.com for the following information, and lets be honest; most of the words.

For those geeks like myself that enjoy a bit of scientific history and trivia, this may not be new information, but to everyone else, the story of Alternating Current (AC), Direct Current (DC), Thomas Edison, Nikola Tesla and Niagara Falls sounds like a made-for-TV movie.

Nikola Tesla, a Serbian by parentage, began working for the Continental Edison Company in Paris in 1882. After gaining praise from his supervisor, he was invited to the US to work alongside Thomas Edison himself. Although Edison thought the man’s ideas were “splendid”, he found them “utterly impractical”. Edison and Tesla both worked long hours, were egocentrics and required little sleep (don’t they sound like a lot of fun to be around… wait, that sounds a lot like me… never mind). Their contrasting work and personal styles, mixed with what seems like sleep deprivation, led to many long, grumpy hours in the workshop.

Edison’s least favorite idea of Tesla’s was the concept of using alternating current technology to bring electricity to the people. Edison was much more partial to his own direct current system, and maintained that the lower voltage from power station to the consumer was safer. AC technology allows for the flow of energy to periodically change direction, and is more practical for transmitting massive quantities of energy over long distances. At the time, DC systems only allowed for a power grid within a one-mile radius of the power source (talk about a case of NIMBY: Not In My BackYard). The conflict between the two technologies, as well as Edison and Tesla’s feud, became known as the War of Currents, hence the not so hidden meaning behind the band name AC/DC.

Tesla eventually sold most of his patents to George Westinghouse (not an unfamiliar name to those familiar with power generation), who built one of the first AC power plants at Niagara Falls to power New York City, and then used the same principles to create much of the modern power grid we have today.

Edison wasn’t wrong however, as the higher voltages of AC are not safe or practical for use in smaller consumer electronics or appliances used in the home; hence the myriad of “power supplies” and converters used in our everyday lives. These converters and power supplies change the higher-voltage alternating current into a lower voltage direct current that can be used more effectively.

So AC and DC technology have been around for quite some time, but what is the difference?

Direct Current

Direct Current (DC) is electrical energy supplied at a constant voltage (approximately). DC is normally used at levels of 24 volts and lower, but can be occasionally seen higher. If plotted on a graph of voltage over time, it may look like the following diagram:

Direct Current Graph

DC is pretty much the standard for point-of-use electrical needs in consumer electronics and anything else that requires very precise and consistent current flow. DC loads can be resistive, capacitive and inductive.

Alternating Current

Most of the electric power in the world is AC. Electricians work with AC about 99% of the time, given its wide use in building electrical systems and its ability to transport energy over long distances. One of the biggest advantages of AC is that is can be transformed and DC cannot. A transformer can step up or step-down voltages as needed for certain devices and depending on what stage of transmission the energy is in. As power always equals the voltage times the amperage, a much larger amount of energy can be transmitted at very high voltages without having to increase the amperage (and therefore wire size). Tesla was a very smart man (if not sometimes foolish; can you imagine what he’d be worth if he hadn’t sold his patents).

Although other methods are available, the most common way of producing AC is by rotating a magnetic field past coils of conductive material, producing an electric current (that whole inductance thing again). The same effect can be created by rotating coils around a stationary magnet. In either case, an electric current is produced in the coil. When the coil is closest to the positive pole of the magnet, the maximum voltage is created in a positive direction. As the magnet is rotated further, the voltage drops increasingly faster until it reaches zero at the time the poles of the magnet are the farthest from the coil. As the magnet continues to rotate, the negative pole gets closer to the coil and the voltage in the coil becomes greater in the negative direction. One complete rotation of the magnet results in one “cycle”, where the voltage starts at zero, reaches its maximum positive value, reaches zero again, reaches its maximum negative value and then returns to zero. The term for cycles per second is called hertz. In the United States, AC is normally provided at 60 Hz (60 cycles per second). Just blew your mind a bit didn’t it? I hope it didn’t hertz too much.   Sorry, I couldn’t resistor.   I kill me.

The diagram below shows the relationship between a rotating point on a circle and the resulting rising and dropping of the voltage. This resultant form is known as a Sine wave, and is one of the most commonly seen wave-forms in nature. Sine waves are also seen in radio waves and any other machine with rotating motion.

Single Phase Animation

Single Phase vs Three Phase

Those professionals who deal with commercial projects have heard the term “Three-Phase Power” more than once, and even the typical homeowner has heard things like “120/240”. I’m sure those terms scare even electricians sometimes as electricity should just be on or off right? Why all the rocket science?

Amazingly, it’s not really difficult.

Single phase power is created when you rotate a magnetic field past one or more connected coils. The resulting voltage and current is always “in phase”, and three times every cycle the voltage is zero. If you generate 120 volts of electricity and then add it to 120 volts of electricity in the same phase, you get double the voltage. This is considered “single-phase” power. In typical residential electrical services, the power company brings two conductors that can each carry 120 volts and a neutral. If you connect say a motor to one of the “hot” conductors and the neutral, it will receive 120 volts. If you connect the motor to both hot conductors, you will get twice the voltage: 240V. Refer to the following diagram to see how the coils of a single-phase generator are “tapped” to get 120 or 240 volts.

Single Phase Power Schematic

Three-Phase Power

Three-Phase power is created by rotating a magnetic field past coils that are spaced 120 degrees apart from each other. Why should this make a difference?

Refer to the following diagrams for clarification, but you’ll quickly see that by spacing the coils equally apart, the sine waves created are also exactly 120 degrees apart. This means that when two or more of the phases are connected together, the resulting voltage never drops to zero. Because the voltage in each phase is offset at any one point, the maximum voltage between two or three phases is not double the single-phase voltage of 120, instead it is equal to the maximum voltage times . If the single phase maximum voltage is 120, then the maximum voltage using two or three of the phases is 208V. I could further explain this correlation using vectors and trigonometry, but don’t you think I’ve beaten you up enough at this point?

3PhaseDiagramShort

3-Phase Diagram

Three Phase Power Schematic

Why use three-phase power?

Three-phase connected motors are much more efficient with the same power and can be used to run longer and with less overall work. If every phase is providing voltage at some point, the motor is never without power. Newton’s 3rd law of motion: A object in motion tends to stay in motion. Keep it going and it takes less work to move it!

OK, time for a metaphor!!

Let’s say you were pushing a small child around on a merry-go-round (yes, they were a very popular playground element before lawyers got involved. See Whatever happened to merry-go-rounds?). One person standing in place could push on the merry-go-round once every time it went around and keep it moving. It would slightly slow down before each push, but you could keep it going. Now put ten kids on that same merry-go-round and one person pushing seems a bit daunting; But, if you were to position three adults around the merry-go-round and each one pushed every time the same spot came by, they’d be pushing three times as much and the fun would never stop; well at least until some poor child decided they’d held onto their lunch long enough. As I’ve said before; metaphors have their limits.

Three phase power is generally limited to commercial use due to the higher number of conductors, and commonly higher voltages, but is nonetheless very common and much more efficient.

Ok, if you have made it this far, I commend your perseverance (or stubbornness). If you understand everything I’ve talked about; please call and re-explain it to me. I may have dozed off in the middle while typing. For your moment of Zen, please enjoy the following animation of a full three-phase genset I modeled. It shows the parts flying away in fantastic fashion. I will try and elaborate on the various parts of the genset in a later post, but for now, enjoy the model and animation that was way more complicated than necessary.

Thank you.

Genset

All graphics and animations in this post, with the exception of the two photos were created by DFD Architects, Inc., ©2018 DFD Architects, Inc. ALL RIGHTS RESERVED. No image, video or animation on this post may be reproduced, transmitted, stored, or used in any form without the prior written permission of DFD Architects, Inc. I’m not kidding.

Gracious Acknowledgements to the following sources for information and selected passages, I couldn’t have written this without their guidance or copying their words:

Delmar’s Standard Textbook of Electricity, Sixth Edition. By Stephen L. Herman. Copyright 2016, Cengage Learning. Kindle Edition.

AC/DC: The Tesla-Edison Feud, by Maggie Ryan Sandford, July 10, 2012. http://www.mentalfloss.com

http://mentalfloss.com/article/30140/acdc-tesla%E2%80%93edison-feud

Thank you especially to my father, John D. Gillen, for passing along just enough of his electrical engineering expertise to make me a geek but remain somewhat socially acceptable.

p.s., I’ll buy a beer for the first (over 21 years of age) person in the State of Texas to correctly identify the location of the facility on the cover image (location name and affiliation). Geeks have to stick together! (Follow up: I’m proud to say my father was the first to get this correct; Extra points to Loyd Dittfurth for also identifying exactly where the image itself came from). For those who still haven’t gotten it; its in a cold and snowy place far far away.

Electricity: Part One

The first in an energetic series of posts on what electricity is and how it’s used, generated and distributed.

We don’t consume electricity; we use energy; transforming it into different forms to make our world brighter, warmer (or cooler) and make work easier. We strive to conserve and efficiently use energy, but in the end, we really only change energy from one form to another. Energy never goes away; it just finds another job to do.

If electricity is only the transportation system for the energy we use, then what is electricity and how does it work?

Although the Money Pit is one of my favorite movies, here is an example of how electricity does NOT behave.

https://youtu.be/VhrSzUm3zhU?t=16s

In the simplest of terms, electrical current is the excitement and flow of electrons. To understand what that means, we need to start with the most basic building block of all matter: the atom. All matter is made from a combination of atoms (either of one kind or multiple). Any substance that cannot be separated into a simpler substance by chemical means is considered an element. All known elements are cataloged within the ‘Periodic Table of Elements’, a table that has stressed out generations of high school chemistry students. The periodic table of elements describes the individual atomic characteristics of each element, and knowing those characteristics gives us more insight into how they all behave with each other. It’s not unlike knowing the personality types of your friends and co-workers.

Periodic-table
The Periodic Table of Elements
Each atom is composed of three basic particles: the electron, proton and neutron. Protons and Neutrons are located in the atom’s nucleus, with the electrons orbiting around in a series of concentric “shells”. Science has uncovered even smaller particles that make up and hold together each atom’s structure, but for our purposes it is the negatively charged electrons (or their absence) that hold the secrets of electricity.

Early scientists such as a Frenchman by the name of Charles Dufay realized that certain materials became attracted to certain objects, but were repelled by others. The forces of attraction and repulsion are described as either a positive or negative charge. As neutrons have no charge, each atom’s nucleus has a net positive charge. As Paula Abdul’s 1988 hit described, “We come together, cuz opposites attract”. Objects with similar charges are repelled from each other, and those with opposite charges are attracted to each other.

At this point, I know that many readers are beginning to have flashbacks to early childhood science class and are wondering, “Where is he going with this? It’s about as exciting as watching paint dry.”

Excitement is exactly what electricity is all about. The outer shell (known as valance electrons) of each atom contains between one and eight electrons. Each atom seeks stability by filling up its outer shell with all eight; a nice calm retirement of sorts. Some atoms like the noble gases Argon and Xenon start out with their outer shells full; they’re calm, unexciting and don’t over-react. Other elements such as gold, silver and copper have only one electron in their outer shell and are more than willing to dance the night away in an attempt to lose that electron and settle down into a more stable existence (a very unlikely outcome given their propensity to getting over-excited). The following animation shows a copper atom, with only one electron in its outer shell. The nucleus, comprised of 39 neutrons and 39 protons is shown as a single sphere at the center (To be honest, I didn’t feel like modeling all 78 spheres in the nucleus; my obsessive nature does have its limits).

Atom Model Moving - 25fps 640x480
Copper (CU),  Animation © DFD Architects, Inc.
At the risk of perpetuating stereotypes, we can group elements and materials by how they behave when excited. In terms of electricity, elements and materials (combinations of elements) can be put into three groups:

Conductors, Insulators and Semi-conductors.

Elements with 3 or less electrons in their outer shells are generally conductors (although the exact number of electrons does not always determine which elements are the best conductors). Because they have lots of empty room in that outer orbit, they are less stable and more likely to lose their remaining electrons when bumped around (The bump theory is a commonly held explanation for how electrons are passed from one atom to another). Insulating materials such as wood, glass and rubber are combinations of elements that fill their outer shells by sharing their electrons with other elements. These materials are composed of elements such as Carbon, Oxygen, Nitrogen and Hydrogen. Alone these elements are not very stable, but combined they have found comfort and stability. Selective elements such as Silicon and Germanium are termed semi-conductors, and have 4 electrons in their outer shell. With a little encouragement these elements can be persuaded to lose an electron or two and become negatively charged. These materials have become indispensable in the development of solid-state circuitry and computers in general.

That bumping around of electrons in a conductor is precisely where the transfer of energy via electricity happens. Like billiard balls on a pool table, when the energy is introduced at one end (the player hitting the cue ball), energy is transferred from one ball to the next. Not all energy is passed from one ball to the next however. In billiards, you’d hear the sound of balls hitting, and if measured, you could see the heat generated by the instantaneous collision. With electrons in a conductor, that energy release may be heat, light and almost always a magnetic field.

Magnets? I thought we were discussing electricity?

Everyone has played with magnets as a kid (or adult). Those of us old enough to remember iron filing and magnet toys such as “Wooly Willy”, have seen what a magnetic field actually looks like. The following image shows a magnet with a negative and positive end (or “pole”) often termed a North and South pole.  The iron filings align with the resultant magnetic lines of force (or ‘flux’). No we are not going to enter into a discussion of whether Santa Claus or penguins reside on either pole (maybe in a later post).

Magnet0873
Patterns of magnetic flux (iron filings and a magnet)
Magnetic fields, created by electrons flowing through a conductive material, are precisely what enables a generator or alternator to initiate the flow of electricity, and appliances such as motors to use that flow of electromagnetic energy to create mechanical movement.

This whole discussion can seem very theoretical, given that we can only see the results of what magnetics and electricity can do. So how do we measure that flow of energy across a conductor?

Before we talk about measuring electricity, it’s important to know why it flows at all. Electromagnetic energy will not flow through anything unless it has somewhere to go. OK, time for a few metaphors:

Everyone is familiar with water pipes in their house, or at least knows that water comes from somewhere when the faucet is turned on. Why doesn’t water flow continuously from the kitchen faucet? It doesn’t flow all the time, because without an open outlet (someone using that water), it will just sit nice and quiet in the pipe. Open a faucet, and the water begins to flow. Break a pipe or create a leak, and water will flow to places you don’t want it to. Electricity is very similar. Without a load, or something to use that energy, there is no need for the electrons to bump into each other and pass along their energy. Unlike the water in our pipes however, electricity wants to flow from a positively charged source to negatively charged one (this is according to popular theory, but let’s leave theory out of this for the moment as it gives me a headache). More often than not, that flow may be from a positive terminal of battery to the negative one, or a positive source to the earth itself (such as in a building’s electrical system). Without a complete “circuit” to follow, the electrons will have nowhere to go, and the flow of electricity will stop. If you provide a complete path for the electricity to follow, then it will happily oblige. There is a reason that they refer to the Formula One race car events as a circuit. If the road was open on both ends and didn’t connect, it would be a very short race. Yes, I’m aware that would be considered drag racing; metaphors have their limits.

Measuring the energy carried by electricity

Before I lose anyone, let’s talk about volts, amps and watts. In my next post we’ll talk about AC/DC, and by that I’m referring to Alternating and Direct Current, not the 80’s band from Australia. I’m sure everyone has heard the phrase, “It’s not the voltage you have to worry about; it’s the amps”. While partially true; why? It has to do with force and potential energy.

If electricity is the flow of electrons, then measuring energy carried by electricity must involve electrons right? Well, unless you have an incredibly powerful microscope, and someone who is really fast at counting, we’re going to need a standard to measure against for counting electrons. Here we learn about Charles-Augustin de Coulomb, a French physicist whom the standard imperial measurement of charge was named after (his story would be another post). One coulomb is equivalent to the charge of 6.242 X 1018 electrons. That’s a lot of electrons. In obnoxiously large numeric terms, that’s six quintrillion, two hundred and forty-two quadrillion electrons. That should be easy enough to put into an Excel spreadsheet, right? Well, instead of counting every electron over a period of time, how about we just divide the total number of electrons by a nice big number like a coulomb? Well it so happens that the volume of one coulomb per second is referred to as an ampere. Whoa! Amps are actually related to something physical?! Don’t get too excited, we’re still talking about theoretically numbers and some basic assumptions, but at least we have somewhere to start.

So if one ampere (normally referred to as an Amp), is a volume of electrons over time, then we should be able to measure the energy those electrons are moving with them right? Not so fast. Volume (or size) is one side of the equation, but we’re missing the other half. We need a push. We need that potential energy to work with.

Caution: Dangerous metaphors ahead.

What is potential energy? If your house was on fire, and you asked for a water hose; I’m sure you’d be rather upset if someone walked up with a garden hose connected to a hand pump. You’d prefer a fire hose connected to a rather large fire truck I’m sure. Why? The difference is in potential energy. Only so much water can flow through a garden hose. Given a bigger and stronger hose, you could push more water through it. Water is normally measured in volume over time; commonly gallons per minute. A garden hose can easily provide 10 gallons per minute, but so can a fire hose. The fire hose however has the potential to provide much, much more water if it is needed (which it usually is). Here’s another example: Let’s say you are sitting quietly at the base of ten-foot cliff, and a rock is perched very precariously above you. It’s not moving, but given a bit of a push, it could fall at any time. If that rock weighed a few grams, the potential for harm to your pretty head is minimal. If that rock weighed 10,000 lbs., then the potential for harm would be rather substantial. Unless it’s actually falling, both rocks are harmless. The 5-ton rock however has a much larger potential energy (it COULD exert a much bigger force).

Since electricity transmits energy, we need to know the volume of energy over time, but we also need to know the level of force with which it is delivered. In terms of water in a pipe, this potential energy is referred to as pressure (in pounds per square inch, or PSI). In the flow of electrons, this potential energy or pressure is called voltage. One Volt is the potential energy it would take to drive one amp of current against a given load (we’ll talk about loads in the next post).

Now we’ve brought energy and force into the equation. Flowing electrons mean nothing if they bump off a conductor one at a time, but if they flow in great numbers (along with their accompanying magnetic fields) with a large amount of force, then now we have energy we can use. With both volume and force, we can move almost anything.

So how do we measure the power or work that electricity provides? Enter the “Watt”. One watt is equal to one volt of potential energy times one ampere of flow. The watt is a measure of the real power that pushes, heats or illuminates. For comparisons, this would be similar to horsepower (735.5 watts), or foot-pounds of force per second (1.355 watts).

In electrical terms, the watt, is proportionately equal to the volts (the potential energy) times the amps (the volume of flow). 1 Watt = 1 Volt x 1 Amp. I know. Some of you just went… uh, duh, but the majority of people just had that little 13 watt LED light bulb (equivalent to a 60 watt incandescent bulb) go off in their head and said, “Oohhhh, I get it.”. You’re welcome.

So let’s stop there for the moment, because unless you’re an electrical engineer or a geek like me, you may need a week to recover from reading this post.

Next time we’ll talk about Direct Current, Alternating Current, Single-Phase Power, Three-Phase Power, generators and transformers. I know, you’ll have a tough time waiting, but it should be worth it.

In the meantime, here is your moment of Zen (Yes, I’m a fan of the Daily Show on Comedy Central):

https://youtu.be/Yzht2_41caU?t=2m

Comments!

I promise not to beg, but I would really welcome any comments; both good and bad (but constructive). The more feedback I get; the better my posts can be. Thanks!!

Copyrights:

The Money Pit, Copyright NBC Universal, 1986

A Christmas Story, Copyright Warner Bros. Home Entertainment, 1983

Magnet and Periodic Table images are public domain and are available on https://commons.wikimedia.org

Why is electricity so hard to understand?

Grasping the concept of electricity is easy once you accept a very simple idea:

Grasping the concept of electricity is easy once you accept a very simple idea:

Electricity is only a transportation system.

We don’t use electricity in our homes, schools and businesses; we use energy. We need energy to do work. Electricity allows us to move the energy we need to do work from one place to another. That work could be mechanical movement, or the creation of light and heat. How do you capture the energy of a strong wind in West Texas; transport it hundreds of miles to your front porch, and then use it to make your ceiling fan blow a gentle breeze on your face on a hot summer evening? You use electricity to move that energy. You’re home or business’ electrical meter is not measuring electricity; it’s measuring the amount of energy you are using. Have you ever noticed that nobody uses the term “Electricity Conservation”? Why is that? Because you can’t consume or conserve electricity. We strive to efficiently use energy. We don’t use up the road as we drive down it, and we don’t run out of water pipe as we take a shower. The medium, or transport method, is entirely different from what moves along it. We are moving and converting energy.

In the end, energy only changes from one form to another. Stored energy is released when fossil fuels are burned to create heat, which boils water to create steam, that spins huge turbines engineered to transfer that energy electromagnetically wherever we need it. Instead of burning limited quantities of fuel, we also use wind turbines to convert mechanical movement into energy we can store and move. Energy never goes away; it just finds a new form and another job to do.

Wouldn’t you like to know why that light comes on when you flip the switch and be able to explain to your child what electricity really is? No, I’m not an engineer or electrician (although having a great electrical engineer for a Dad does help), but understanding and explaining the basics is something everyone can do. Through a series of posts in the coming weeks, I’m going to explain the underlying concepts of electricity, how we use it to transform and move energy, and explain the systems and equipment that allow us to harness the unbelievable power our universe provides us. It will involve some physics, a little chemistry, some easy math, funny examples of what electricity does not do, and hopefully just enough humorous metaphors to lighten the load (pun intended). In the end you probably won’t be ready to install a distribution panelboard, repair the control board in  your flat screen TV, or be qualified to go anywhere near a high voltage power line, but I think it will change the way you look at the world around you.

I hope it sparks your interest.