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

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Unit 3, Lesson 6

Introduction

Unit 3: International Electricity: Generation, Use, and Demand – Lesson 6: Electricity Energy Sources: Non-Renewable

About Lesson 6

Building on concepts learned in Lessons 1 and 2, Lesson 6 begins by taking a closer look at how electricity is generated by large-scale producers. The lesson then focuses on the electricity generation from non-renewable sources such as coal, natural gas, and nuclear; including fuel sources, process byproducts, and environmental issues. Other concepts covered in the lesson include carbon capture, carbon sequestration, combined-cycle, and combined heat and power (CHP).

What will we learn in Lesson 6?

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

  • describe commercial-scale electricity generation from non-renewable fuel sources;
  • list non-renewable energy sources along with fuel sources, process byproducts and environmental issues related to each;
  • explain the carbon-management methods of carbon capture and sequestration;
  • describe combined-cycle and combined heat and power applications.

What is due for Lesson 6?

The table below provides an overview of the requirements for Lesson 6. 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 6 Requirements
REQUIREMENT LOCATION SUBMITTED FOR GRADING?

Reading: (How Power Plants Work): "The Role of Turbines in Power Generation"

Page 2 No
Reading: (Coal): DOE "Energy Explained" (as designated) Page 3 No
Reading: (Coal): "Carbon Capture and Storage Association" (as designated) Page 3 No
Reading: (Coal): Clean Coal: Fact or Fiction Page 3 No
Reading: (Coal): Is EOR a Dead End for Carbon Capture and Storage? Page 3 No
Reading: (Natural Gas): DOE "Energy Explained" (as designated) Page 4 No
Reading: (Natural Gas): A dirty little secret Page 4 No
Reading: (Natural Gas): DOE "Fossil Energy, LNG" Page 4 No
Reading: (Nuclear): DOE "Energy Explained" (as designated) Page 5 No
Reading: (Nuclear): Nuclear power industry revamps climate pitch for Trump Page 5 No
Interactive Tool: (Your Energy Lab Site): Execute EPA Power Profiler as instructed Page 5 No
Lesson 6 Activity: Complete Lesson 6 Activity. (It's in Canvas, in the Unit 3 Module) Page 6 Yes
Unit 3 Discussion Forum: "Smart Grid" (It's in Canvas, in the Unit 3 Module) Page 7 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.

 

How a Power Plant Works

Lesson 2 described how generators turn motion energy into electrical energy. A generator works on the phenomenon of electromagnetic induction, discovered by Faraday nearly 200 years ago. When an electrical current passes through a wire, a magnetic field is generated around it. Likewise, if the magnetic field around a wire is changed (for example by rotating magnets inside a stationary coil or by rotating a coil inside a stationary magnet), electricity will move through the wire.

drawing of the inside of a generator. Thouroughly described in text.
Figure 6.1: Generator.
Credit: CEC [1]

Commercial generators used in power plants are very large quantities of copper wire spinning around inside very large magnets, at very high speeds. A turbine spins the shaft that runs the generator. A turbine is an assembly with blades attached that converts the motion of liquids or gases into mechanical motion. Water wheels and windmills are familiar examples of turbines.

There are many different kinds of turbines. Many power plants use steam turbines to generate electricity. These plants use any of a variety of methods to create steam to drive the generator. They may burn fuels (such as coal, natural gas, oil, and biomass), use nuclear, or concentrated solar to heat the water and create the steam, or use geothermal energy directly from the earth. In all cases, the steam runs through a huge multi-stage turbine to spin an output shaft that drives the plant's generator.

Hydroelectric plants use water turbines to generate power. The turbines used in a hydroelectric plant look completely different from a steam turbine because water is so much denser (and slower moving) than steam, but it is the same principle. Flowing (or falling) water pushes against the turbine blades, causing it to spin.

Wind turbines, also known as wind mills, use the wind as their motive force. A wind turbine looks nothing like a steam turbine or a water turbine because wind is slow moving and very light. The principle is the same though—the wind pushes against the turbine blades, causing it to spin.

In a gas turbine, a pressurized gas spins the turbine—fuels are burned to generate hot gases which go through a turbine, causing it to spin.

Steam turbine generators (e.g., coal, natural gas, biomass, nuclear), hydroelectric power plants, wind farms, gas turbine generators all operate on the same principle—magnets + conductor (wire) + motion = electric current. The electricity produced is the same, regardless of the energy source used to turn the turbine.

(Sources for much of the information on this page: Mass Engineers [2] and The Electricity Forum [3].)

Reading Assignment

From Diesel Service and Supply, read “The Role of Turbines in Power Generation [4]”

Shown below, the U.S. Energy Information Administration [5] describes energy sources used for electricity generation in the U.S. in 2016.

What is U.S. electricity generation by energy source?

In 2016, the United States generated about 4 trillion kilowatthours of electricity at utility-scale facilities. About 65% of the electricity generated was from fossil fuels (coal, natural gas, and petroleum).

Energy sources and percent share of total for electricity generation in 20161

  • Coal 30%
  • Nuclear 20%
  • Natural Gas 34%
  • Hydropower 6.5%
  • Biomass 1.5%
  • Geothermal 0.4%
  • Solar 0.9%
  • Wind 5.6%
  • Petroleum 1%
  • Other Gases < 1%

1 Preliminary data; based on generation by utility-scale facilities.

Coal-Powered Electricity Generation

Reading Assignments

Visit Department of Energy, Energy Explained [6]

  • Under “Nonrenewable Sources", read "Coal" and all subpages.

Clean Power Plan (CPP)

What is the Clean Power Plan (CPP)? It's a brand new regulation from the EPA that sets state-by-state targets for reducing the carbon emissions from electricity generating power plants. (Previously, there has been no rules limiting the emission of carbon dioxide from power plants.) The CPP gives states different options for meeting their targets. With the CPP, national electricity emissions will be reduced by about 32% in 2030, compared to 2005 levels.

We could do an entire course about the Clean Power Plan! Here's an essential timeline and overview.

First, some context...

The combustion of fossil fuels to generate electricity is the largest single source of CO2 emissions in the nation. (EPA, Carbon Dioxide Emissions [7])

In 2015, emissions from electricity generation accounted for about 37% of total energy-related U.S. CO2 emissions.  (EIA Frequently Asked Questions [8])

In 2015, about 33% of US electricity came from coal. Yet, coal accounted for about 71% of CO2 emissions from electricity generation in the United States. (EIA Frequently Asked Questions [8])

Timeline...

Under the Federal Clean Air Act (enacted decades ago) and with the support of a Supreme Court decision in 2014, the Environmental Protection Agency (EPA) is authorized to regulate major sources of greenhouse gas emissions.

In 2015, the EPA finalized regulations that address emissions ("carbon pollution") for both existing and new/modified power plans. "On August 3, 2015, President Obama and EPA announced the Clean Power Plan – a historic and important step in reducing carbon pollution from power plants that takes real action on climate change. Shaped by years of unprecedented outreach and public engagement, the final Clean Power Plan is fair, flexible and designed to strengthen the fast-growing trend toward cleaner and lower-polluting American energy. With strong but achievable standards for power plants, and customized goals for states to cut the carbon pollution that is driving climate change, the Clean Power Plan provides national consistency, accountability and a level playing field while reflecting each state’s energy mix. It also shows the world that the United States is committed to leading global efforts to address climate change.' (EPA Rule Summary [9])

In December 2015, "representatives of 195 nations reached a landmark accord that will, for the first time, commit nearly every country to lowering planet-warming greenhouse gas emissions to help stave off the most drastic effects of climate change." (New York Times, Nations Approve Landmark Climate Accord in Paris [10])

On Feb 9, 2016, the Supreme Court made the unprecedented decision [11] to put the Clean Power Plan on hold while a group of states continued to fight it out in lower courts. This surprise decision raised obvious concerns that the same conservative-leaning Supreme Court would ultimately take the case and strike down the Clean Power Plan.  It also raises into question the U.S.'s ability to keep its recent Paris climate action commitments and the domino effect that may have on the international deal altogether.

Four days later, February 13, 2016,the most-conservative judge on the Supreme Court, Antonin Scalia [12], died suddenly. His replacement will be a significant factor in the future of the Clean Power Plan.

Fast forward. Current headlines (Feb 14, 2017), Trump Eyes EPA Visit To Announce Limits On Agency After Pruitt Sworn In [13], with this, "Another [executive] order could direct EPA to begin the process of revoking the Clean Power Plan (CPP) and related new source performance standards to reduce power sector GHGs." While others repor [14]t that the administration may have to, by law, provide some plan for reducing carbon dioxide emissions (per the 2014 Supreme Court decision).

Stay tuned...more about all of this in the final unit of this course!

Carbon Capture and Storage (CSS)

Carbon Capture and Storage (CCS) is one group of technologies for managing and controlling carbon dioxide emissions. The International Energy Agency [15] gives this definition, "Carbon capture and storage, or CCS, is a family of technologies and techniques that enable the capture of CO2 from fuel combustion or industrial processes, the transport of CO2 via ships or pipelines, and its storage underground, in depleted oil and gas fields and deep saline formations. CCS can have a unique and vital role to play in the global transition to a sustainable low-carbon economy, in both power generation and industry."

Reading (and a little viewing) Assignments

Visit the Carbon Capture & Storage Association [16] (CCSA). Using tabs at the top,
  • under What is CCS?, read page titled What is CCS? and watch quick video "The Hard Facts"
  • under Why CCS?, read "Tackling climate change" (video not required)
  • under Why CCS?, under CCS projects, read (closely scan) "International CCS projects"

Odd Bedfellows?

You may have noticed...the CCSA descriptions of international CCS projects mention "natural gas development" and the "Weyburn oil field" for "enhanced oil recovery." (Weyburn is a large city in Saskatchewan, Canada, an area that would be served by Keystone XL pipeline).

Weren't we just talking about CCS as a means of cleaning up coal? for capturing carbon? for avoiding emissions and helping in the transition to a low-carbon economy? Let's take a closer look.

Figure 6.2: The Statoil-operated Snøhvit field in the Barents Sea supplies gas to the world’s first LNG plant with CO2 capture and storage.
Credit: Statoil [17]

Investopedia [18] defines enhanced oil recovery (EOR) as "the process of obtaining stranded oil not recovered from an oil reservoir through certain extraction processes. EOR uses methods including thermal recovery, gas injection, chemical injection and low-salinity water flooding."

All of the current CCS projects listed on the CCSA site use captured carbon dioxide for enhanced oil recovery.

So, we have this very odd triangle: Carbon Capture and Storage technologies : "Clean Coal" power generation : "Oil & Gas" enhanced recovery!

Reading Assignment

Read Clean Coal: Fact or Fiction? [19] (October 2016) in Inside Energy, by Stephanie Joyce

Reading Assignment

Read Is EOR a Dead End for Carbon Capture and Storage? [20] (April 2016) in Power, by Thomas Overton

Natural Gas-Powered

Reading Assignment

Visit Department of Energy, Energy Explained [6].

  • Under “Nonrenewable Sources", read "Natural Gas" and all subpages.

Reading Assignment

  • Read A dirty little secret [21] (from The Economist, July 2016)

Natural gas can be used to generate electricity in many different ways. The section below, from naturalgas.org [22], provides a broad overview.

Steam Generation Units

Natural gas can be used to generate electricity in a variety of ways. The most basic natural gas fired electric generation consists of a steam generation unit, where fossil fuels are burned in a boiler to heat water and produce steam, which then turns a turbine to generate electricity. Natural gas may be used for this process, although these basic steam units are more typical of large coal or nuclear generation facilities. These basic steam generation units have fairly low energy efficiency. Typically, only 33 to 35 percent of the thermal energy used to generate the steam is converted into electrical energy in these types of units.

Centralized Gas Turbines

Gas turbines and combustion engines are also used to generate electricity. In these types of units, instead of heating steam to turn a turbine, hot gases from burning fossil fuels (particularly natural gas) are used to turn the turbine and generate electricity. Gas turbine and combustion engine plants are traditionally used primarily for peak-load demands, as it is possible to quickly and easily turn them on. These plants have increased in popularity due to advances in technology and the availability of natural gas. However, they are still traditionally slightly less efficient than large steam-driven power plants.

Combined Cycle Units

Many of the new natural gas fired power plants are what are known as 'combined-cycle' units. In these types of generating facilities, there is both a gas turbine and a steam unit, all in one. The gas turbine operates in much the same way as a normal gas turbine, using the hot gases released from burning natural gas to turn a turbine and generate electricity. In combined-cycle plants, the waste heat from the gas-turbine process is directed towards generating steam, which is then used to generate electricity much like a steam unit. Because of this efficient use of the heat energy released from the natural gas, combined-cycle plants are much more efficient than steam units or gas turbines alone. In fact, combined-plants can achieve thermal efficiencies of up to 50 to 60 percent.

Distributed Generation

Until recently, methods of generating power have been discussed in the context of large, centralized power plants. However, with technological advancements and deregulation in the electricity industry, there is a trend moving towards what is known as 'distributed generation'. Distributed generation refers to the placement of individual, smaller sized electric generation units at residential, commercial, and industrial sites. These small scale power plants, primarily powered by natural gas, operate with small gas turbine or combustion engine units, or natural gas fuel cells.

Distributed generation can take many forms, from small, low output generators used to back up the supply of electricity obtained from the centralized electric utilities, to larger, independent generators that supply enough electricity to power an entire factory. Distributed generation is attractive because it offers electricity that is more reliable, more efficient, and cheaper than purchasing power from a centralized utility. Distributed generation also allows for increased local control over the electricity supply, and cuts down on electricity losses during transmission.

Natural gas is one of the leading energy sources for distributed generation. Because of the extensive natural gas supply infrastructure and the environmental benefits of using natural gas, it is one of the leading choices for on-site power generation. There are a number of ways in which natural gas may be used on-site to generate electricity. Fuel cells, gas-fired reciprocating engines, industrial natural gas-fired turbines, and microturbines are all popular forms of using natural gas for on-site electricity needs.

Industrial Natural Gas Fired Turbines

Industrial natural gas-fired turbines operate on the same concept as the larger centralized gas turbine generators discussed above. However, instead of being located in a centralized plant, these turbines are located in close proximity to where the electricity being generated will be used. Industrial turbines – producing electricity through the use of high temperature, high pressure gas to turn a turbine that generates a current – are compact, lightweight, easily started, and simple to operate. This type of distributed generation is commonly used by medium and large sized establishments, such as universities, hospitals, commercial buildings, and industrial plants, and can achieve efficiency up to 58 percent.

In contrast with distributed generation, the heat that would normally be lost as waste energy can easily be harnessed to perform other functions, such as powering a boiler or space heating. This is known as Combined Heat and Power (CHP) systems. These systems make use of heat that is normally wasted in the electric generation process, thereby increasing the energy efficiency of the total system.

In addition, on-site natural gas turbines can be used in a combined cycle unit, as discussed above. Due to the advantages of these types of generation units, a great deal of research is being put into developing more efficient, advanced gas turbines for distributed generation.

Microturbines

Microturbines are scaled down versions of industrial gas turbines. As their name suggests, these generating units are very small, and typically have a relatively small electric output. These types of distributed generation systems have the capacity to produce from 25 to 500 kilowatts (kW) of electricity, and are best suited for residential or small scale commercial units.

Advantages to microturbines include a very compact size (about the same size as a refrigerator), a small number of moving parts, light-weight, low-cost, and increased efficiency. Using new waste heat recovery techniques, microturbines can achieve energy efficiencies of up to 80 percent.

Natural Gas-Fired Reciprocating Engines

Natural-gas fired reciprocating engines are also used for on-site electric generation. These types of engines are also commonly known as combustion engines. They convert the energy contained in fossil fuels into mechanical energy, which rotates a piston to generate electricity. Natural-gas fired reciprocating engines typically generate from less than 5 kW, up to 7 megawatts (MW), meaning they can be used as a small scale residential backup generator to a base load generator in industrial settings. These engines offer efficiencies from 25 to 45 percent, and can also be used in a CHP system to increase energy efficiency.

Fuel cells are becoming an increasingly important technology for the generation of electricity. They are much like rechargeable batteries, except instead of using an electric recharger, they use a fuel, such as natural gas, to generate electric power even when they are in use. Fuel cells for distributed generation offer a multitude of benefits, and are an exciting area of innovation and research for distributed generation applications.

Reading Assignments

Visit Department of Energy, Fossil Energy [23]
  • Under "Science and Innovation", select "Oil & Gas", then use "+" by Oil & Gas to find and click on "LNG". In "Liquified Natural Gas" and read first two sections (opening section and LNG Basics). More if you like!

 

Nuclear-Powered

Reading Assignment

Visit Department of Energy, Energy Explained [6].

  • Under “Nonrenewable Sources", read "Nuclear" and all subpages.

Reading Assignment

Read Nuclear power industry revamps climate pitch for Trump era [24] (Feb 2017)

Interactive Assignment

Visit Environmental Protection Agency [25]

  • To begin using Power Profiler, enter the zip code for your ELS and follow instructions.

If your ELS is located outside of the USA, please pick a zip code in the USA of interest to you for this exercise. The zip code for Penn State's main campus is 16802. That may be a good choice!

 

Lesson 6 Activity

Complete the Lesson 6 Activity. (It's in CANVAS, under Modules, Unit 3.)

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.

Discussion Forum

Unit 3 Discussion Forum: "Smart Grid"

A report from the White House presents estimates of weather-related power outages costing the US economy $25 to $70 billion a year (inflation adjusted). These costs include lost output and wages, spoiled inventory, delayed production, inconvenience and damage to the grid itself.  Severe weather is the "number one" cause of power outages in the United States and the number of outages caused by severe weather is "expected to rise as climate change increases the frequency and intensity of hurricanes, blizzards, floods and other extreme weather events." (Economic Benefits of Increasing Electric Grid Resilience to Weather Outages [26], Executive Office of the President, August 2013.)

Power failures are expensive, disruptive and can be dangerous. After no significant power losses for a decade, our home has been without power for weeks over the last several years, a result of changing weather and aging infrastructure--freak ice storms, Sandy, local equipment failure. All events were costly in terms of work productivity, loss of property and expensive emergency measures to find safe and warm temporary housing. Compounding the misery, like many, we received poor or no information about the status of our service, and the info we did receive was often very wrong. We received numerous calls from the utility and even a visit from a worker to tell us our service was restored when the street was still lined with downed poles. (Can you imagine THAT conversation?) I'm sure many of you have your stories too!

One possible remedy to help prevent and then manage before, during and after grid failures is the smart grid. Recent events, like severe winter weather and Hurricane Sandy, have drawn attention again to the Smart Grid. The promise of its benefits are beyond mitigation of power outages, however, it may also help us use energy more efficiently through information and personal behavior as well as automation and intelligent controls. The Smart Grid could also help integrate distributed generation smoothly into the grid, especially important for intermittent renewable energy sources such as solar and wind. ("Distributed generation" simply means the electricity is generated at or near its point of use.)

In this discussion, we'll talk about what the smart grid is, its promises and challenges and what it may mean to you.

Use material from the lesson and your own independent research. In your posting, please address the following:
  • In your own words, briefly describe what the smart grid is.
  • Ask someone in your everyday life to describe the Smart Grid. How did they do? (Tell us!) How well do you believe the public understands what the smart grid is?
  • Research and share one new piece of information about the smart grid (not something covered in the lesson). Please give source, of course.
  • What do you see as the two most promising features (benefits) of the smart grid to society? What do you see as the biggest challenges?
  • How do you think the smart grid would be of benefit to you directly? What, if anything, about the smart grid might concern you, worry you, personally?
Respond. Read the postings of others and respond to at least one.

Please define and explain any acronyms or abbreviations you use (GHG = greenhouse gas) and wherever possible include links to your references. Any questions, just let me know!

Post your work in the Discussion, "Smart Grid" You'll find it in CANVAS, in the Unit 3 Module. Please follow full instructions there.

Read the postings of others and respond to at least one. Follow up on any postings made to your comment.

Please see Canvas calendar 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 quality of your participation. Be interesting and interested! Please see Syllabus for full Discussion Forum grading criteria.

 

Summary and Final Tasks

Summary

In this lesson, you learned about commercial production of electricity and the role of turbines and electricity generation from non-renewable energy sources. For coal, natural gas and nuclear, you learned about fuel sources, byproducts, and environmental issues. We also covered special topics including carbon capture, carbon sequestration, combined cycle, and combined heat and power.

Reminder—Complete all of the lesson tasks!

You have finished Lesson 6. Double-check the list of requirements on the Lesson 6 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/p6.html

Links
[1] http://www.energyquest.ca.gov/story/chapter06.html
[2] http://www.massengineers.com/Documents/howgasturbinework.htm
[3] http://www.electricityforum.com/electricity-generation.html
[4] http://www.dieselserviceandsupply.com/Turbines.aspx
[5] http://www.eia.gov/tools/faqs/faq.cfm?id=427&amp;t=3
[6] http://tonto.eia.doe.gov/energyexplained/
[7] http://www3.epa.gov/climatechange/ghgemissions/gases/co2.html
[8] http://www.eia.gov/tools/faqs/faq.cfm?id=77&amp;t=11
[9] http://www.epa.gov/cleanpowerplan/clean-power-plan-existing-power-plants
[10] http://www.nytimes.com/2015/12/13/world/europe/climate-change-accord-paris.html?_r=0
[11] http://www.nytimes.com/2016/02/10/us/politics/supreme-court-blocks-obama-epa-coal-emissions-regulations.html?_r=0
[12] http://nymag.com/daily/intelligencer/2016/02/how-scalias-death-will-change-everything.html
[13] https://insideepa.com/daily-news/trump-eyes-epa-visit-announce-limits-agency-after-pruitt-sworn?utm_source=dlvr.it&amp;utm_medium=twitter
[14] http://www.eenews.net/tv/videos/2200/transcript
[15] http://www.iea.org/topics/ccs/
[16] http://www.ccsassociation.org/
[17] http://www.statoil.com/en/TechnologyInnovation/NewEnergy/Co2CaptureStorage/Pages/Snohvit.aspx
[18] http://www.investopedia.com/terms/e/enhanced-oil-recovery.asp
[19] http://insideenergy.org/2016/10/11/clean-coal-fact-or-fiction/
[20] http://www.powermag.com/is-eor-a-dead-end-for-carbon-capture/
[21] http://www.economist.com/news/business/21702493-natural-gass-reputation-cleaner-fuel-coal-and-oil-risks-being-sullied-methane
[22] http://naturalgas.org/overview/uses-electrical/
[23] http://fossil.energy.gov/programs/oilgas/storage/index.html
[24] http://www.sciencemag.org/news/2017/02/nuclear-power-industry-revamps-climate-pitch-trump-era
[25] http://oaspub.epa.gov/powpro/ept_pack.charts
[26] http://energy.gov/sites/prod/files/2013/08/f2/Grid%20Resiliency%20Report_FINAL.pdf