Published on EGEE 401: Energy in a Changing World (https://www.e-education.psu.edu/egee401)

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Unit 1, Lesson 1

Introduction

Unit 1: Energy Principles – Lesson 1: Energy Forms

About Unit 1 and Lesson 1

What is "energy"? Technically defined as "the ability to do work," energy is the hot in heat, the glow in light, the push in wind, the pound in water, the sound of thunder and the crack of lightening. It is the pull that keeps us (and everything else!) from simply flying apart, and the promise of spring deep in an acorn. It is all the same, and it is all different. How does a gallon of gas move a car 20 or more miles? How can faraway falling water cause the lights in my house to operate? Before launching into our conversation about the energy industry and its changing role in our world, in Unit 1, we consider the fascinating essence of energy in nature, including its many forms and transformations. We'll review systems of measurement and other basics, like energy vs. power and the first law of thermodynamics.

What will we learn in Lesson 1?

With the successful completion of this unit, you will be able to:

  • describe energy in many natural forms;
  • relate energy to power;
  • work with energy-related units of measurement and convert between systems;
  • relate energy concepts to the world around you.

What is due for Lesson 1?

The table below provides an overview of the requirements for Lesson 1. For details regarding the assignment, refer to the page(s) noted in the table.

Please refer to the Calendar in CANVAS for specific time frames and due dates.

Lesson 1 Requirements
REQUIREMENT LOCATION SUBMITTED FOR GRADING?
Reading: Energy Explained [1] (designated sections), US Energy Information Administration. Page 2 No
Lesson 1 Activity: Complete Lesson 1 Activity. (It's in CANVAS, under Modules, Unit 1) Page 4 Yes
Unit 1 Discussion: Energy's Pace of Change. (It's in CANVAS, under Modules, Unit 1) Page 5 Yes

Questions about EGEE 401?

If you have any questions, please post them to our Questions about EGEE 401? discussion in CANVAS. Use this Discussion for general questions about course content and administration. I will check it daily to respond. While you are there, feel free to post your own responses if you, too, are able to help out a classmate or have a related question.

 

Energy Concepts

Energy is neither created nor destroyed. Energy is in everything. It exists in many different forms, morphing easily from one form to another. It is heat, light, motion and the possibility of motion! It holds the molecules in our body together, and separates the seas from the skies. It is lightning and wind and sunshine and waves and oil and plants. It is your body and mine. Before we talk about energy in the sense of the energy industry—the preparation and delivery of energy for an intended use at a specific location, it’s useful to consider the innate qualities and properties of energy.

In science, we simply define energy as “the ability to do work.” We can measure energy. If we define a system to measure—say a ball at the top of a ramp, then let the ball roll down the ramp and bump into something, or use a stretched rubber band to turn a paddle in water, or eat a dozen donuts—these are all forms of energy morphing into another form of energy. The total amount of energy before and after is exactly the same, though it is in different forms. The energy that was in the ball is now in the obstacle it hit. The energy from the rubber band is now in the slightly warmed water. The donuts are in your belly, as energy to be used or stored.

Energy exists in many different forms. Some forms of energy can help us do things we need or want to do. When it is in the form of heat, energy warms our homes, bath water, and cars. When it is in the form of motion, energy carries us places in cars and trains and airplanes. When it is in the form of electricity, it gives us light and runs our appliances and electronics. We need energy in a useful form, when and where we need it, and in the right quantity.

If you are in an electric car, a gallon of diesel fuel will not help. If your house is heated with oil, electricity will not warm you. If your office runs on electricity, a load of coal isn’t going to turn equipment on. Sunshine and waterfalls won’t start your car, and wind won’t run the dishwasher. BUT, if we match the form and timing of the energy with your needs, all of these things could be true.

Energy in a changing world, then, is about both ends of the stick. The form of the energy delivered and how it is used. Much of the energy used in this country, and around the world, is in the form of electricity. We don’t get electricity directly from nature, by catching lightning in a jar, but instead we get it by transforming energy from other forms into the form of electricity. We do this because electricity is a convenient form of energy to move and manage. When the electricity gets to where it is going, it is then transformed into another form of energy to do whatever it is we need it to do—turn on our lights, heat our water, charge our batteries, play our music. Similarly, the engines that run our cars and equipment convert energy from one form to another—from the chemical energy in a fuel into motion. And, all along the way, it takes energy to manage and deliver energy!

Throughout this course, we are going to refer back to the natural processes underlying the energy industry—energy in its many natural forms and the basic process of transforming one form to another. In the first two lessons, we are going to review the many forms of energy and the basic transformation processes. Then, we will talk about how they relate to our energy industry, the environment and our security.

Reading Assignment

Visit the U.S. Energy Information Administration site, Energy Explained [1].

  • Read "What is Energy" and all subpages.
  • Read "Units and Calculators" and all subpages.
  • Read "U.S. Energy Facts" and all subpages (notice multiple tabs on first page).

 

Energy and Power

The terms "energy" and "power" are easily (and often) confused in casual conversation. They are related concepts, but distinctly different. We'll use them carefully throughout this course. We know energy is defined as "the ability to do work." Power is how fast (or slow) the work is done. It may take the same amount of energy to walk or run up a steep hill, but it takes more power to run than to walk.

Power is the time rate at which work is done or energy is transformed. (In calculus terms, power is the derivative of work with respect to time.) From the reading, you learned about some common units of measure for energy: kilowatt-hours, BTUs, Joules (megajoules), and calories.

Power is measured in units of “energy per time.” For example, BTU/min and Joules/sec. A common unit of measure of power is “horsepower.” This measure can be converted to other power units of measure expressed as “energy/time”. For example, 1 horsepower = 2,545 BTU/hour.

A Watt is another measure of power defined as 1 Joule/sec. A Watt-hour or kilowatt-hour is the measure of energy. 1 horsepower = 756 Watts. When we're talking about electricity, we use Watts to describe power and Watt-hrs (or kilowatt hours, kWh) to describe energy.

Maybe this will help...think of a light bulb rated at 100 Watts. This is the power rating for the bulb. It tells us how much electricity the bulb can transform into light and heat over a given amount of time. If left on for one hour, a 25-W bulb will use 25 Watt-hours (Wh) of energy.

one 25 W light bulb and one 100W light bulb as described in text.
Figure 1.1: Power and Energy.
Credit: V. Cole

In the same amount of time, a 100 W bulb will use four times as much energy as a 25 W bulb. If you leave them both on for one hour, the 25-W bulb uses 25 Watt-hours (Wh) of energy and the 100-W uses 100 Watt-hours of energy. After 3 hours, it’s 75 Wh and 300 Wh respectively.

The power company charges you based not on how many light bulbs you have, but for how much energy they use while you have them turned on. The same is true for all electrical loads. You are charged for the energy they use (power x time), usually measured in kilowatt-hours (kWh).

Resource

Here's a good site for a wide range of international unit conversions, Unit Converter [2]. Try it, especially for energy and power unit conversions. You may find it helpful for some of the assignments in the course.

 

Lesson 1 Activity

Complete the Lesson 1 Activity. (It's in CANVAS, under Modules, Unit 1.)

Unless noted otherwise, correct answers come directly from the content of this lesson and assigned readings.

The Activity consists of a variety questions of different types, which may include true/false, multiple choice, multiple select, fill in the blank, ordering, and short answer. The point value varies and is indicated for each. Some questions are graded automatically, and some are manually graded.

The quiz is not timed, but does close at 11:59 pm Eastern Standard Time on the due date as shown in CANVAS.

Questions that are "manually graded" will be scored based on the correctness and quality of your answers. Thinking is good! Try to make your answers as orderly and clear as possible. Short is good, as long as you fully answer the question. Help me understand what you are thinking, and include data where relevant.

Numbers must ALWAYS be accompanied by units of measure (not "300" but "300 kW").

Proofread and spell check your work.

Unit 1 Discussion

Unit 1 Discussion: "Energy's Pace of Change"

The Transient Phenomenon of Fossil Fuels
Figure 1.2: The Transient Phenomenon of Fossil Fuels.
‘Beyond Fossil Fuels: Assessing Energy Alternatives’, T.W. Murphy Jr., chapter 15 in ‘State of the World 2013: Is Sustainability Still Possible?’, The Worldwatch Institute, Island Press, 2013.

Most discussions in the remarkable trajectory of human development in the past few years label the phenomenon the Industrial Revolution. This term is apt enough, although it emphasizes the industrious nature of clever humans. An equally important factor--if not more so--has been the abundant supply of cheap surplus energy in the form of fossil fuels. Coal fueled the early stages of the Industrial Revolution, opening the door to accelerated energy-resource discovery and exploitation. Indeed, the first major application of coal was to power steam engines used to pump water out of mines in order to gain access to more coal. Perhaps the Coal Revolution would more accurately represent the transformational change marked by the 19th century.

Fossil fuel stocks are known to be finite, and by most accounts their extraction rates will peak this century. Thus in the long view it is a near certainty that the current age will be known to history as the Fossil Fuel Age. It is the time when humans discovered Earth's battery--solar-charged over millions of years--and depleted it fast enough to effectively constitute a short circuit.

During this epoch, our unprecedented capacity to process materials, manufacture goods, create a "built environment," and revolutionize agricultural productivity has translated into a world of spectacular accomplishments, advanced scientific knowledge, technology that an earlier generation might call magic, sustained economic growth, and a surging population of 7 billion industrially fed human beings. These feats would not have been possible without the bounty of fossil fuels.

In this light, our present state can be seen as a reflection of historically available energy. If depicted in a schematic fashion over the course of a civilization-scale timeline, the general history and future of fossil fuel use will very likely appear as a sharp spike. (See Figure [above]). Humanity now sits near the apex of the brief fossil fuel energy explosion and prepares to enter an untested regime of unprecedented scale: the loss of a resource that has been unquestionably vital to growth and development.

The passage above is excerpted from "Beyond Fossil Fuels: Assessing Energy Alternatives," an essay by T.W. Murphy, an Associate Professor of Physics at the University of California/San Diego. It is Chapter 15 of a book entitled, "Is Sustainability Still Possible?" published in 2013 by the Worldwatch Institute. I find this book to be an extraordinary collection of well-written and researched essays on a wide range of topics. It is not required that you purchase this book for this course, but it is near the top of my list of recommended reading. You may wish to check it out!


The title of this course is "Energy in a Changing World." "Changing" is an understatement! My grandfather was born in 1903. He loved to remark that in the course of his lifetime the Wright brothers took their first flight and a man walked on the moon. Incredible. In terms of energy, let's consider where we were just "yesterday" and think about how quickly "tomorrow" will come.

It is natural to think things have always been as they are and will continue to be so. But we don't have to look back very far to find a world that was very different from today's, especially when we focus on changes related to our use of energy. When we look forward and ponder future energy options, it is necessary to be open and realistic about the rate and scope of change that is possible, in fact, probable.

Take a minute to look at the Figure above. The steep slopes of the spike shows how rapidly our use of fossil-fuel has increased, and will then decrease. In energy terms, the world was very different just a generation ago and the one before that--our parents' world and our grandparents' world.

My mother talks about when her parents first had central heating installed. Before that, only two rooms in the house were heated. Growing up, my mother never had a heated bedroom. My grandfather chopped and hauled wood and used coal purchased locally. It was all heavy hard work. Suddenly, all he had to do was push a little lever on the thermostat and the whole house would get warm. My mother said that, for years, he would stand by the thermostat and marvel at what a miracle it was, so grateful for the ease and ability to keep his family warm. My grandmother grew up traveling in a horse-drawn buggy. Her mother was an excellent driver, they say! She used to laugh about buying jello from a door-to-door salesman, before they had a refrigerator! (Life without a refrigerator. Can we imagine that?) My mother's family was typical, maybe considered "well to do" in their small rural community. They were the first in the area to have a telephone. Neighbors would come from all around to use the phone that still hangs in the central hall. I remember when they got an air conditioner, in the 1960s. It was installed in a window in the den and they'd turn it on for an hour or so on hot afternoons. As hot and humid as it was in South Carolina, this one window unit was the only air conditioning in any of my family homes (counting our own home and my grandparents) for my entire childhood. Sounds like I'm 220 years old, right? I'm 56.

Activity

For this Discussion, we're going to collect and share stories about the changing use of energy in recent generations. As we look back on those stories, we're going to spin the stage and "ask" our grandchildren to look back on our times. What will they find noteworthy about the way we use energy?

  • Interview. Find someone in your world who is at least 75 years old and ask them to describe how the use of energy has changed in their lifetime. Ask them to think about their childhood and then to think about now. Consider heating and air conditioning, transportation, infrastructure, appliances, and other related topics. Do they remember stories from their parents on these topics? See what you can learn that is interesting and share it in your posting. Give us some points of reference, including where the person lived, rural or urban, etc. (You are not required to give any personal details.) If you do not have access to anyone to interview, you may share and discuss an interesting story, image, or fact found through your own research that demonstrates how the role of energy in our lives has changed over the last 100 years.
  • Personal Reflection. Imagine it is 50 years from now and these same questions are being asked of you by your grandchildren. "Describe how the use of energy changed over your lifetime." In 50 years, looking back, what would we say about our use of energy today? What will be interesting, surprising, noteworthy? (Be sure to keep the focus on looking back at today. Don't put too much effort into describing the future. We'll go there in the last Discussion of this course!)
  • Respond. Read the postings of others and respond to at least one.

Post your work in the Discussion, "Energy's Pace of Change." You'll find it in CANVAS, under Modules, Unit 1. Please follow full instructions there.

Include both the Interview and your personal reflection in your initial posting.

Please see course calendar in CANVAS for due date of your FIRST posting and date when discussion ends (graded participation ends, all replies must be in).

Grading criteria

You will be graded on the completeness and quality of your participation. Be interesting and interested! Please see Syllabus for full Discussion grading criteria.

 

Summary and Final Tasks

Summary

In this lesson, you examined the basic forms of energy and the relationship between energy and power. You learned about units of measure for energy and power. You also started to think about and discuss the "big picture" of the challenges facing our energy industry and the environment.

Reminder—Complete all of the lesson tasks!

You have finished Lesson 1. Double-check the list of requirements on the Lesson 1 Overview page to make sure you have completed all of the activities listed there before beginning the next lesson.


Source URL: https://www.e-education.psu.edu/egee401/content/p1.html

Links
[1] http://tonto.eia.doe.gov/energyexplained/index.cfm?page=about_home
[2] http://www.digitaldutch.com/unitconverter/power.htm