The purpose of this lesson is for you to review key concepts from Lesson 1 (Energy and Sustainability) of EMSC 240N. I strongly encourage you to at least browse through Lesson 1 [1] of EMSC 240N, though that is not required.
By the end of this lesson, you should be able to:
To Read | Lesson 1 Online Content | You're here! |
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To Do |
Lesson 1 Quiz Lesson 1 Journal Entry Lesson 1 Discussion Board Post #1 |
Canvas Modules > Lesson 1 Canvas Modules > Lesson 1 Canvas Modules > Lesson 1 |
If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
Thermodynamics is defined by NASA [2] as "the study of the effects of work, heat, and energy on a system." Any time you discuss energy transfer, assess the efficiency of a piece of equipment, or analyze the conversion of energy from one form to another, it involves thermodynamics.
Energy is defined as "the ability to do work," and work is the transfer of energy or the application of force across a distance. If this were a Physics or Thermodynamics course, we'd be more concerned about work, but for better or worse it is not, so we will stick to focusing on energy. For the purposes of this course, there are a few important things to remember about energy:
The following discussion of energy forms is taken nearly word-for-word from EM SC 240N. Direct quotes are from this reading from the National Energy Education Development (NEED) Project [3], which you are welcome, but not required, to read.
The two categories of energy are potential and kinetic. Potential energy is stored energy and kinetic energy is energy in motion. The forms of energy are as follows:
Differentiating the various forms of energy is usually straightforward, but I have noticed that people often confuse thermal and radiant energy. This is probably because most people associate "thermal" with "heat," so when something generates heat, it is assumed that thermal energy is being released. Please keep in mind that radiant energy travels in waves, and is released by everything above absolute zero (humans have never observed absolute zero). Radiant energy emanates in all directions from everything, and the hotter the object, the more and more intense radiant energy it emits. All radiant energy is invisible to the human eye except for energy in the visible spectrum. Thermal energy, on the other hand, is energy in the vibrating molecules of a substance. Again, everything above absolute zero has thermal energy, i.e., its molecules are vibrating. Thermal energy is contained within the molecule(s) and is not emitted.
Energy is constantly changing forms all around you (and everywhere else on earth) all of the time. All forms of energy can end up as all other forms of energy, and recall that the First Law of Thermodynamics dictates that all energy, irrespective of its form, comes from somewhere else. Again, the following is taken almost word-for-word from EM SC 240N.
Take a few minutes to look around you. Based on what you know about energy, what is energy “doing” where you are right now? What forms can you identify? (Seriously, take a look.)
Considering I can't see you right now (Or can I? Hmm...), I'll just give you a few probable examples. If you are inside, light is coming from somewhere, whether it’s a light bulb on the ceiling, sunlight coming through a window, or at least coming from the screen you are looking at (this is electromagnetic/radiant energy). Any sound you hear is sound energy. Everything around you is radiating heat, which is a form of radiant/electromagnetic energy. Since everything in and around you has a temperature above absolute zero, it has vibrating molecules and thus thermal energy. If you are moving at all - even the slightest twitch of an eyelid - your body is using motion energy. Merely thinking about this question requires your brain to use electrical energy.
We could go on and on. But as you probably know, these are all examples of kinetic energy. There are also a number of types of potential energy around you. Think of some examples of potential energy around (and in) you right now. You are able to move and think because of chemical (potential) energy inside of your body. In fact, everything around you has chemical potential energy. Any object on the wall, on a table, attached to the ceiling, or just above the ground has gravitational (potential) energy because it is above the ground. There is also nuclear (potential) energy in all matter because all matter has at least one nucleus. Again, we could go on and on, but the point is that everything around you has potential energy, and thus has the ability to do work, i.e., “to make things happen.”
All of the examples of energy that were noted above came from somewhere else. The light coming from a light bulb is converted from electrical energy running through a wire. The heat radiating from non-living things around you was absorbed from another source such as sunlight or the heating system of the building. The motion and electrical energy your body has right now come from the chemical energy inside of your body. The gravitational energy of things around you came from motion energy required to lift the objects. And so on. And recall that each time energy was transferred, work was done.
Efficiency is an often used term when discussing energy, e.g., "I have an efficient car," "How efficient is your furnace?", and "The average efficiency of a coal-fired power plant is around 33%." Though the term is thrown around a lot, it has a specific meaning. Energy efficiency is the amount of useful output per unit of input. The "useful" part of that definition is important since the First Law of Thermodynamics requires that all energy that goes into something must go somewhere.
The video below provides a very good explanation and animation of how a coal-fired power plant works. Think it's as easy as dumping a bunch of coal into a furnace and turning a turbine? Watch the video to find out.
All energy-using (and generating) technologies have an efficiency - TVs, light bulbs, solar panels, cell phones, wind turbines, airplane engines, electric motors, you name it. One important aspect to know is that when energy is converted, it is physically impossible to convert all of the energy into useful output. In other words, it is not possible for anything to be 100% efficient. This is dictated by the Second Law of Thermodynamics. The Second Law has other implications, but they are not important in the context of this course. If you'd like to learn more about the Second Law, see the video below and/or this [8]link.
The second law can be confusing, but the narrator in the video below does a pretty good job of explaining some aspects of it.
Renewable energy is defined by the U.S. Environmental Protection Agency [9] thus: "Renewable energy includes resources that rely on fuel sources that restore themselves over short periods of time and do not diminish." Non-renewable energy is energy that cannot restore itself over a short period of time and does diminish. It is usually easy to distinguish between renewable and non-renewable, but there are some exceptions (more on that in a minute).
Fossil fuels are fossilized hydrocarbons made from organic material. They are considered "fossilized" because they take millions of years to form, they are hydrocarbons because they are made mostly of hydrogen and carbon, and of course organic material refers to living or recently living things.
The three primary fossil fuels used in the world are coal, oil, and natural gas. (As noted in EM SC 240N, oil and natural gas are technically made up of multiple hydrocarbons, but they are each conventionally referred to as individual hydrocarbons.) Feel free to read through the U.S. Energy Information Administration's (U.S. EIA's) summaries of coal [10], oil [11], and natural gas [12] before reading the summaries below.
Since all fossil fuels started out as plants or animals, all of their energy comes from the sun. The solar energy (all radiant energy) is stored as chemical energy when the plant undergoes photosynthesis, then is stored as chemical energy in the fossil fuel itself. It is (usually) released when the fuel undergoes combustion, which results in thermal and ultimately radiant energy release. Note that the physical material of fossil fuels does not come from the sun - the carbon, for example, is pulled from the atmosphere during photosynthesis - but the energy that is released when coal, oil, or natural gas is burned was once solar energy.
Nuclear energy, as discussed above, is the energy that holds the nucleus of atoms together. Nuclear energy in nuclear power plants is extracted using fission of uranium atoms. Fission releases radiant energy, which is used to heat water to steam and turn a turbine, which spins a generator and generates an electrical current. The sun utilizes fusion (fusing hydrogen together to form helium atoms), which then releases radiant energy.
As noted above, renewable energy sources "restore themselves over short periods of time and do not diminish." For a thorough explanation of many renewable energy sources, see this site from the U.S. EIA [13]. A more thorough explanation of these sources is provided later in this course.
As you are no doubt aware, a primary sustainability concern regarding energy use is carbon dioxide (CO2) emissions. A carbon-free energy source emits no carbon when energy is being generated. Solar, wind, hydroelectric, and nuclear energy are commonly used carbon-free sources. Carbon neutral sources release CO2 but have no net impact on the CO2 concentration of the atmosphere because they release no more CO2 than was absorbed from the same atmosphere. Biomass is the only carbon-neutral source of energy. Recall that biomass gets its energy from the sun by virtue of it being used by photosynthetic organisms to grow. Biomass is made mostly of carbon, which is integrated into the biomass when CO2 is absorbed from the surrounding air. When said biomass is converted to useful thermal/radiant energy via combustion, the same or less CO2 is released, resulting in a net zero impact on carbon dioxide concentrations. To summarize:
It will help to at least skim through this page of EM SC 240N [18] prior to reading this material, but it is not necessary.
As I'm sure you are aware, the terms sustainable and green are used in many contexts and in many sectors of society. Sustainable growth, sustainable energy, green business, sustainable fashion, green cars, sustainable food, and sustainable consumption are just a small sample of how the terms are used. Many people in the sustainability field (myself included) are concerned that the term has been overused to the point that it is almost meaningless. Robert Engelman, President of the Worldwatch Institute [19], refers to this phenomenon as "sustainababble" in his "Beyond Sustainababble [20]" chapter from Is Sustainability Still Possible?. While this excessive usage of the term is undesirable, it is in some ways understandable because a) sustainability relates to everything that humans do and b) it has become an effective way to market products. Selling stuff to the masses drives the economy (consumer spending historically [21] constitutes around 65% - 70% of U.S. GDP), though such rampant consumerism ironically has a largely negative impact on sustainability. You may recall that EM SC 240N was largely designed to cut through a lot of this "sustainababble," and help you understand what sustainability really means. This course will offer a review of a lot of the concepts in that course, as well as provide some additional ones.
See below for a summary of key sustainability points from Lesson 1 of EM SC 240N:
Sustainability and sustainable development are often thought of as having three core components: environment, economy, and equity. These are commonly referred to as the "3 Es" of sustainability. The 3 Es is a useful way to provide an analytical framework for sustainability. This 3E framework is useful because it provides questions that can be asked when investigating whether or not something is sustainable. While even these terms can be defined in various ways, we will use the following definitions from the reading when analyzing the sustainability implications of something:
The following provides a few more details about each of the 3 Es:
I have a challenge for you: think of something that you did in the past week that did not involve energy.
Okay, so that's not really a fair challenge. Everything we do, even thinking about things that we might do, requires energy. Here's a more reasonable challenge: think of something that you did in the past week that did not involve the use of non-renewable energy.
Any food you eat almost certainly required non-renewable energy. There are obvious connections like farm machinery, artificial fertilizers, and herbicides, transporting food, refrigerating food, cooking food, and packaging food. But even if you grow your own, you likely used a tool or fencing that was manufactured using non-renewables, seeds that were processed and shipped with fossil fuel-using machines, packaging that was made using non-renewable energy, or maybe even plastic row markers made with petroleum-based plastics. Almost all transportation uses non-renewables, most businesses run on non-renewable energy sources (either directly or indirectly through electricity generation), almost all of the products you buy contain materials either made of or that are processed with fossil fuels. The electronic device you are looking at right now is partially made of and manufactured using fossil fuels. In short, modern society is very dependent upon access to non-renewable energy, particularly fossil fuels. As Asher Miller notes in The Post Carbon Reader:
Look around and you'll see that the very fabric of our lives - where we live, what we eat, how we move, what we buy, what we do, and what we value - was woven with cheap, abundant energy. (p. xiv)
The charts below provide some insight into the U.S. and global energy regimes. The first chart is from the International Energy Agency, and the other is from the U.S. EIA. Both are excellent sources of energy information. Please take a look at them and read through the descriptions, and keep in mind that there is one final summative point provided below.
There are a few interesting things to point out from the chart above.
The charts below provide rather dramatic evidence of how important non-renewable energy is to the U.S. Both charts are from the EIA's Annual Energy Outlook (AEO) series, which are published on a yearly basis. A few things worth pointing out:
It should be clear that the vast majority of energy used worldwide comes from non-renewable sources, and this is unlikely to change any time soon. This has a lot of sustainability implications, which we will address in more detail later. From systems thinking perspective, it is important to realize that everything you do requires energy, and it is important to think about where that energy comes from and what the sustainability implications are.
That's it for Lesson 1! Hopefully this review helped solidify these concepts for you. By now you should be able to:
Double-check the to-do list on the Lesson 1 Overview page [28] to make sure you have completed all of the activities listed there before you begin Lesson 2.
Links
[1] https://www.e-education.psu.edu/emsc240/node/383
[2] http://www.grc.nasa.gov/www/k-12/airplane/thermo.html
[3] http://cse.ssl.berkeley.edu/energy/Resources/Intro%20to%20Energy%20Reading.pdf
[4] https://www.flickr.com/photos/potat0man/8106833946
[5] http://www.fueleconomy.gov/feg/atv.shtml
[6] https://www.achrnews.com/articles/124595-doe-leaky-ducts-are-top-energy-waster
[7] https://www.eia.gov/electricity/annual/html/epa_08_01.html
[8] http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html
[9] http://web.archive.org/web/20150405010943/http://www.epa.gov/greenpower/gpmarket/
[10] https://www.eia.gov/energyexplained/index.php?page=coal_home
[11] https://www.eia.gov/energyexplained/index.php?page=oil_home
[12] https://www.eia.gov/energyexplained/index.php?page=natural_gas_home
[13] https://www.eia.gov/energyexplained/index.php?page=renewable_home
[14] https://www.eia.gov/energyexplained/index.php?page=solar_home
[15] https://www.eia.gov/energyexplained/index.php?page=wind_home
[16] https://www.eia.gov/energyexplained/index.php?page=hydropower_home
[17] https://www.eia.gov/energyexplained/index.php?page=biomass_home
[18] https://www.e-education.psu.edu/emsc240/node/508
[19] http://www.worldwatch.org/
[20] https://www.e-education.psu.edu/emsc470/sites/www.e-education.psu.edu.emsc470/files/Beyond%20Sustainababble%20-%20Engelman.pdf
[21] http://www.stlouisfed.org/publications/regional-economist/january-2012/dont-expect-consumer-spending-to-be-the-engine-of-economic-growth-it-once-was
[22] http://www.un-documents.net/our-common-future.pdf
[23] http://www.epa.gov/sustainability/learn-about-sustainability#what
[24] https://www.ncdc.noaa.gov/indicators/
[25] http://www.iea.org/publications/freepublications/publication/KeyWorld2017.pdf
[26] https://www.eia.gov/outlooks/archive/aeo15/
[27] https://www.eia.gov/outlooks/aeo/pdf/0383(2017).pdf
[28] https://www.e-education.psu.edu/emsc470/808