Energy Sources and Water Usage

May. 18, 2011 | 0 Comments | Science | 9-12 | Energy

Lesson Steps

Warm Up: Introduction to Water in Energy Sources

1.Start this lesson by reading the statements below. Students should decide if they think they are true or false. Ask students to raise their hands to indicate their answers.

a. Nuclear power plants use a substantial amount of water in the process of making electricity. True.

b. Coal power plants use a substantial amount of water in the process of making electricity. True.

c. Solar power plants use a substantial amount of water in the process of making electricity. True.

2. Ask which of these three energy sources they think uses the most water. Then, explain that in this lesson they will examine the answers to this question and more concerning electricity generation and water usage.

 

Activity One: How Do Our Sources of Energy Use Water?

1.Pass out copies of Reproducible #1– Energy Sources and How They Use Water and Reproducible #2 – Energy Sources and How They Use Water Follow-up Questions. Explain to students that this assignment provides background information on various sources of energy including the fuels we use (coal, natural gas and oil) and the energy sources used to produce electricity (nuclear fission, coal and natural gas, hydropower and solar). Each of these sources of energy uses water at various steps, and the major uses of water are outlined.

2.Ask students to read the background and then answer the follow-up questions. They can do this in class or as a homework assignment.

 

Activity Two: Energy-Water Photo Matching Game

By playing a photo matching game, the sources of energy and uses of water will become more concrete to students.

1. Pass out copies of Reproducible #4 – Matching Energy Sources to Photos Challenge and Reproducible #5 – Matching Energy Sources to Photos Challenge Answer Sheet. Explain to your students that they will be matching each photo to one of the explanations, which are lettered. These photos will help them to better visualize each source of energy and some of the ways water is used in the production process. This could be done as a homework assignment, but would probably work best in class with students working in small groups.

2. Review the answers as a class.

 

Activity Three: Comparing Water Use and Energy Sources: A Graphing Activity

1. Pass out copies of Reproducible #7 – Graphing Water Intensity of Energy. Explain to students that they will be graphing the intensity of water usage of different sources of energy. Water Intensity Energy is the total amount of water, calculated on a whole-system basis, required for the generation of electricity; often expressed as the number of gallons of water required to produce one Megawatt of electricity and is expressed as gal/MWh.[1]

2. Let your students know whether you would like them to graph the data by hand or by using your preferred graphing software program. This can be done in class or as a homework assignment.

3. Go over the answers to the worksheet as a class. Then, use the following questions to close the activity:

1. What results surprised you?

2. What questions did this raise in your mind?

3. What challenges do you think our society might face as we seek to produce more energy for a growing population?

 

Wrap Up: Energy, Water and Your Future Productivity

1. Ask students how the use of water during the production of energy is connected to future productivity (their own, in the region, in the U.S. and globally).

a.  How does the population of an area relate to water and energy? A growing population will require larger amounts of energy to be produced, and this will require larger quantities of water to be used.

b. How does natural resource distribution relate to energy? Water is already a limited resource in several parts of the United States and world. Limited water can result in limited energy.

c.  How does resource limitation relate to productivity? Water shortages and/or the rising cost of water are inhibitive to productivity in the affected region or area. This could also result in a rising cost of energy sources that use large amounts of water.

 

Extension:

1. Make copies of Reproducible #9 – Energy versus Water: Solving Both Crises Together and Reproducible #10 – Energy versus Water: Solving Both Crises Together Questions. Ask students to read the article and answer the questions as homework. Then facilitate a discussion using the questions on Reproducible #10.

a)  Why did the state of Florida plan to sue the U.S. Army Corps of Engineers for its plan to reduce water from Georgia reservoirs? The reservoir water runs into the Apalachicola River, which flows through Florida. Florida was concerned that less water flow would threaten certain endangered species.

b) Why did the state of Alabama object to the Corps’ plan? The reduced flow of water might shut down a nuclear power plant in Alabama.Why would the nuclear power plant be threatened? It uses vast amounts of water from the Apalachicola River for cooling to help condense steam back into liquid water.

c) To what lengths might Georgia be willing to go to guarantee freshwater? Georgiahas considered moving its northern border one mile farther north to access freshwater resources now located in Tennessee.

d)  What is causing a shortage of water in the south? A rapidly growing population, drought, overdevelopment, and a lack of planning for broader water conservation.

e) What is the paradox the author describes on the first page? When water is limited, less energy can be produced; rising energy costs are hurting efforts to supply even greater amounts of clean water.

f)  What is an example of this paradox if Lake Mead in Nevada continues to be lowered? Las Vegas would have to ration water use and the Hoover Dam might not be able to produce much energy, limiting electricity to Las Vegas.

g) Why are activists fighting a plan in San Diego to construct a desalination plant (a plant that removes salt from salt water to produce fresh water)? Desalination plants use a lot of energy and the supply of energy is already stretched thin.

h) What does the author think the solution to the water-energy paradox requires? New national policies that integrate energy and water solutions; innovative technologies that help to boost one resource without draining the other.

i)  Why is trucking water to water-stressed areas and cleaning dirty water supplies not the best solutions for providing clean water to water-stressed areas? Both use a large amount of energy. Energy can be in limited supply and is costly.

j)   What are the two greatest users of freshwater in the United States? Agriculture and power plants.

k) Which of the two resources—water or energy—does the author think is ultimately more important and why? He feels water is more important because it is more immediately crucial for life and there is no substitute for it.

 

CONCLUSION

Students examined specific ways water is used in the process of extracting, processing, generating, transporting and consuming various sources of energy. By playing a matching game using photos of energy sources and processes, they were able to more concretely visualize the steps in extraction, processing, and generation of energy. After graphing data on water intensity of different forms of energy, they compared which use the most water per megawatt of electricity generated. Finally, they considered how the use of water during energy production is connected to future productivity.

 

[1]“Integrated Water and Energy Policies,” Agriculture and Natural Resources - University of California Water Resources Coordinating Conference, April 19, 2007. Retrieved 17 March 2010 from http://groups.ucanr.org/waterquality/documents/2007_Water_Resources_Coordinating_Conference11456.pdf.