Coal and Your Community

Transcription

1 Activity 4 oal and Your ommunity Activity 4 oal and Your ommunity Goals In this activity you will: Investigate the production and consumption of coal in the United States. Investigate how coal sources are explored. Understand methods of coal mining. Determine how coal is used in your state. Evaluate possible practices to conserve coal resources. Think about It oal production in the United States decreased in 1999 and 2000, but coal consumption continues to increase. Why do you think that the production of coal has decreased? Why do you think that the consumption of coal has increased? Given that coal is a finite, nonrenewable source of energy, what are some ways to extend the supply of coal? What do you think? Record your ideas in your Earthomm notebook. Be prepared to discuss your responses with your small group and the class. 835 oordinated Science for the 21st entury

2 Energy Resources Investigate Part A: Trends in oal Production and onsumption Table 1 United States oal Production, by Region (in million short tons 1 ) Year Appalachian Interior Western Total Source: United States Energy Information Administration, 1996, 1998, One short ton = 2000 pounds. 1. Table 1 gives recent trends in coal production in the United States during the last 10 years. Using these values, summarize the trends in coal production for the three major coalproducing regions, and the trend in total coal production. a) Appalachian b) Interior c) Western d) Total 2. Make one graph showing coal production in the three regions. Leave room at the end of the graph to project coal production for the next 50 years. a) Include your graph in your Earthomm notebook. 3. Extrapolate the trends in the data to the year To do this, you will have to produce a best-fit line through the data points and estimate what you think to be the trend in coal production. There is a little guesswork involved in determining how much of the data you think represents the trend. Is it the last four years or the last eight years? a) On the basis of your projections only (you are ignoring all other factors that might influence future production), which coal-producing region do you predict will be the first to exhaust its supply of coal? In what year will this happen? b) In your group, identify at least three factors that might affect actual coal production. Record your ideas in your notebook. Earthomm 836

3 Activity 4 oal and Your ommunity 4. Examine the data in Table 2. Summarize the major trends in coal consumption for each sector from 1991 to 2000, and the total coal consumption. a) Electric power b) oke plants (steel manufacturing) c) Other industrial plants d) Residential and commercial users e) Total f) What percentage of total coal consumption did electrical power make in 1991? In 2000? Table 2 United States oal onsumption by Sector, (in million short tons 1 ) onsumption by Sector (million short tons) Residential Other and Electric oke Industrial ommercial Year Power Plants Plants Users Total Source: United States Energy Information Administration, 1996, 1998, One short ton = 2000 pounds. 5. Using the data from Table 2, make a graph that shows coal consumption for electrical power. a) Include the graph in your Earthomm notebook. 6. Extrapolate the trend in the data to the year 2050, as in Step 3. a) On the basis of recent trends, how much coal will be needed for electrical power generation in the year 2020? 2050? 7. oal consumption for electrical power increased at an average rate of 1.65% per year between 1996 and a) On the basis of this average, predict coal consumption for electrical power for the years 2010 and 2020 (Hint: Begin by multiplying the value for the year 2000 by This gives you a prediction for the year 2001.) 837 oordinated Science for the 21st entury

4 Energy Resources 8. Assume that by conserving electricity the average rate of growth in consumption of coal is cut in half, to 0.825% per year. a) Predict the amount of coal consumed in 2010 and Draw a new graph that shows your prediction of coal production and coal consumption for the period 2000 to Do this by superimposing the curves you fitted in Steps 3 and 6. Also, in a third curve, take into account the prediction you made in Step 8, on the assumption of savings by conservation. a) Include your graph in your Earthomm notebook. b) Do you predict that consumption will exceed production? If so, how do you think that the shortfall in production will be made up? Or do you predict that production will exceed consumption? If so, do you think that that is a reasonable or likely scenario? c) In what ways do you think that production and consumption are related? Does production drive consumption? If so, how and to what extent? Or does consumption drive production? If so, how, and to what extent? Table 3 Logs for ore Holes (elevations are in feet above sea level; ms = mudstone, ss = sandstone). Location 1 Location 2 Location 3 Location 4 Location ms ms ss ss ss coal ss ms ms ms ms ms ss ss coal coal coal ms ms ms ms ms coal ss coal coal coal ms ms ms ms ms coal coal ms coal coal ms ms coal coal ms ms Part B: oal Exploration 1. In 1998, the Western Region overtook the Appalachian Region as the largest coal-producing region in the United States with million short tons produced, up by 8.3% over The low-sulfur Powder River Basin coal fields in Wyoming dominated growth in coal production in the Western Region. The diagram on the following page shows a cross section of five core holes drilled along an east west line. Table 3 provides drilling results for these wells. The results include the elevations and types of rock units in the core holes. Earthomm 838

5 Activity 4 oal and Your ommunity elevation in feet West core hole East core core hole 2 hole 3 hole core core hole a) omplete the cross section in the diagram. Match up the rock units as you imagine them to be connected in the subsurface. (Hint: The mudstone at the bottom of all five wells is the same unit.) b) ompare your results with those from other members of your group. How do they compare? How do you explain the differences? c) Where would you drill your next well in order to determine whether or not your interpretation of the cross section is correct? Explain. d) Is the information in the cross section sufficient to determine the coal seam with the greatest volume of coal? Why or why not? e) What is the average thickness of coal in the lower coal seam? f) Assume that the lower coal seam covers an area of 300,000 acres and that each acre-foot yields 1770 short tons of coal. (An acre-foot is the volume of a 1-foot thick layer that covers an area of 1 acre.) How many short tons of coal does the lower coal seam contain? elevation in feet Part : onserving oal Resources 1. A 100-W bulb burning for 10 h uses 1 kwh (kilowatt-hour) of electricity (the same as ten 100-W bulbs burning for one hour). a) alculate the kilowatt-hours of electricity used in one year for a 100-W bulb running continuously. 839 b) Assume that electricity costs $0.06/kWh. (Your teacher may give you a more accurate figure for your community.) alculate the yearly cost of running the 100-W bulb continuously. c) Assume that one pound of goodquality coal can produce about 1 kwh of electricity. alculate the amount of coal required per year to keep the 100-W bulb running continuously. d) How much coal is required each year to keep a 100-W bulb burning continuously in 20 million households? e) What do you think are the environmental consequences of burning this much coal? f) The average electricity bill for a family of four in the United States is about $50 per month (this is for homes where cooking and heating are by natural gas or oil). Estimate the yearly amount of electricity (in kilowatt-hours) that this is equivalent to. How many tons of coal are needed? 2. A variety of researchers are currently seeking methods to reduce our consumption of electricity, much of which is produced from coal. In your group decide on five ways to make oordinated Science for the 21st entury

6 Energy Resources homes (or offices) in your community more energy efficient. Go to the Earthomm web site for useful links that will help you to explore ways to conserve energy resources. Suggestions are provided below. Water heaters How do you ensure the best energy efficiency of an electric home water heater and reduce energy costs? Major home appliances What are the most efficient ways to use major home appliances and how can you improve their efficiency? Home tightening How can you slow the escape of heat energy from buildings, saving money and making them more comfortable? Insulation How can insulation be used to reduce energy consumption? Home cooling What strategies can you suggest for keeping a building cool in summer and improving the efficiency of air conditioning units? a) Record the methods that you decide on in your notebook. 3. For each method you decided on, describe the method of improving energy efficiency, the science behind it, and make sample calculations of cost savings and natural resource savings over 1 year and 10 years (based upon the cost of electricity in your community). Divide up the work in your group. a) How much electricity would be saved? b) How much coal would be conserved over the course of a year? Over 10 years? 4. onservation (reduction in use) is another way to reduce energy usage. a) In your group, decide on 10 ways to conserve energy. b) alculate the savings. Source: Energy Information Administration, Electric Power Monthly March gas 16% nuclear 20% Earthomm hydro 7% petroleum and other 5% Figure 1 Percentage share of United States electric power industry net generation. Digging Deeper OAL EXPLORATION AND MINING coal 52% In 2000, over 52% of electricity in the United States was produced from coal (see Figure 1).There was a fall in coal production around the middle of the last century.this was in part due to the decline of the steel industry, which uses coal in steel production. In addition, oil and gas have largely replaced coal for transportation and home heating. Since the early 1960s, however, there has been a steady increase in the production of coal.this is mainly because of the increasing demand for electricity.there has also been a development of major coalfields in the western United States and anada. 840

7 Activity 4 oal and Your ommunity Of all fossil fuels, the largest reserves are contained in coal deposits (92%).Three major factors determine which coals are currently economical for mining. One factor is the cost of transportation to areas where the coal is utilized. Another factor is the environmental concern associated with the mining and use of coal. From a geologic perspective, the quality, thickness, volume, and depth of coal are important in determining whether or not a coal is mined. coal elevator miner's elevator shaft mine Underground Mining Methods original land surface rock spoil drift mine slope mine coal beds Figure 2 Different methods used to mine coal from the ground. Figure 2 illustrates underground and surface mining methods (Note:You would not typically see all these mining methods used in one location.) Underground mining methods include drift, slope, and shaft mining. Surface mining methods include area, contour, mountaintop removal, and auger mining. (An auger is a tool used for boring a hole.) Figure 3 shows a surface coal mine. Surface Mining Methods dragline removing mountain top dozer along contour bench auger mining dragline in pit coal beds rock spoil heck Your Understanding Figure 3 A mine high wall showing layered sandstone and mudstone in a Gulf oast coal mine.the haul truck provides a sense of scale. 1. What are the major factors that determine whether a coal seam is economically and geologically suitable for mining? 2. What are the major factors that have determined the trends in coal consumption during the 20th century? 841 oordinated Science for the 21st entury

8 Energy Resources Understanding and Applying What You Have Learned 1. Think about historical differences in electricity use. ompare your community s electricity use 10 years ago and today. 2. Estimate the total energy use of your community. How much could your community reasonably conserve? 3. ompare electricity usage of a single college student vs. a family of four. Which group uses more electricity per person? 4. Think about regional differences in electricity use. Which part of the country do you think would be the lowest? Which part of the country do you think would be the highest? What are the reasons for your opinions? Preparing for the hapter hallenge Assume that your community is expected to grow 10% in the next 10 years. If electricity usage remains the same, this means that the electrical capacity required to meet this increase must also increase. This may be undesirable and involve the cost of building a new power plant or an increased environmental hazard. Determine specific steps that could be taken by the community to conserve electricity. How would the reduced demand for electricity offset the growth in the community? What incentives would be given to encourage the community to implement these proposed changes? Inquiring Further 1. Investigating a coal mine Investigate the coal mine closest to your community. a) What mining method do they use? b) What is their annual production? c) How has the mine influenced the economy of the community? d) Has the mine impacted the environment? e) What steps has the mining company taken to reduce the environmental impact of the mine? Have your teacher arrange a field trip to this mine and discuss the trip with your class. 2. Electricity usage in other countries Find out information about electricity usage in other countries. What can you learn from other countries about energy conservation? (For instance, Japan has a high gross national product (GNP) yet very low energy use. How do they manage this?) 3. Personal electricity usage Learn how to read your electricity meter, and with your family conduct some conservation experiments for a few days (or weeks) and report the results of these experiments to the class. Earthomm 842