The Connection Between Water Use and Energy Use

Apr. 15, 2011 | 0 Comments | Math | Science | Social Studies | 9-12 | Energy

Lesson Steps

Warm-Up: PSA on Energy and Water

1. Begin the lesson by showing a thirty secondpublic service announcement that earned Honorable Mention in the U.S. EPA's 2009 Water Quality Video Contest. It illustrates the connection between water and energy consumption. Find this public service announcement, “Conserving Water Conserves Energy,” on YouTube at this address: http://www.youtube.com/watch?v=MwO1wp-EAYk. While this PA announcement does not explain the connection between energy and water, it is simple and provocative and will act as an excellent introduction to this lesson.

2. Ask your students if they knew that letting their faucet run for five minutes uses about as much energy as letting a 60-watt light bulb run for 14 hours?[1] Why might this be? Because water is required in large quantities to produce many of the sources of energy that we rely upon. For example, 39% of all freshwater withdrawals made in the United States is dedicated to the production of electricity through fossil fuels and nuclear power.[2]

3. Explain to your students that they will be exploring this little-understood relationship between water and energy.

 

Activity One: Linking Water Use and Energy

1. Pass out copies of Reproducible #1 – Discovering the Connections between Water Use and Energy. Ask students to work in pairs or small groups. Touch base with the students as they work through the sheet, clarifying and discussing any questions they may have.

2. As students arrive at question #7 of this packet, pass out copies of Reproducible #3 – Cost-Effective Ways to Save Water at Home. This handout will help them think about the personal steps they would be willing to take to save water.

3. Review the answers as a class. Then, hold a short discussion using the following questions:

·        Was there anything on this sheet that sounded familiar or that you knew already?

·        What did you learn that was new to you?

·        What surprised you most?

·        What new questions did this packet raise for you? What would you like to know more about?

·        What information do you think is important to share with your family?

·        Do any of these issues affect your community or region more than others?

 

Activity Two: Linking Energy Use and Water

1. Pass out copies of Reproducible #4 – Discovering the Connections between Energy Use and Water. This packet could be completed in class with students working in small groups, or as a homework assignment.

2. When finished, review the answers as a class. Then, hold a short discussion using the following questions:

·        Was there anything on this sheet that sounded familiar or that you knew already?

·        What did you learn that was new to you?

·        What surprised you most?

·        What new questions did this packet raise for you? What would you like to know more about?

·        What information do you think is important to share with your family?

·        Do any of these issues affect your community or region more than others?

 

Activity Three: Conduct a Home Water Audit

1. Explain that you would like each student to conduct an audit of water usage at their home. An audit involves determining how much water is used and identifying steps that can be taken to save water. Performing audits can help families save money on their water and utility bills. Conducting an audit can also make your students more conscious of how their family uses water and how water can be saved. Remind students that by saving water they are also saving energy and reducing the carbon emissions that go into the atmosphere.

2. Reproducible #6 – Information on Conducting a Household Water Audit and Reproducible #7 – Personal Water Audit contain a range of information about conducting home water audits to collect a variety of household and/or personal usage data. Walk students through the steps of conducting the audit, letting them know which information they will be collecting for their assignment.

a. If they will be auditing their household water utilities bill or reading the water meter in their home, they will likely have to ask for adult guidance to obtain a copy of the bill or locate the water meter.

b. The Water Footprint Calculator (found under “Your Footprint Calculator” at www.waterfootprint.org) is a great online tool that will allow your students to calculate their extended water footprints (equal to the water required to produce the goods and services they consume). You may also recommend that students use online audits such as: North Carolina Cooperative Extension Service Water Quality and Waste Management’s Saving Water and Saving Energy (http://www.bae.ncsu.edu/programs/extension/publicat/wqwm/he251.html), the U.S. EPA’s WaterSense Calculator (http://www.epa.gov/watersense/calculate_your_water_savings.html) or the Maryland Department of the Environment Water Supply Program’s Residential Water Audit (http://www.mde.state.md.us/assets/document/ResAudit.pdf).

c.  You may even ask students to do more than one type of water audit and compare the results, making hypotheses to account for any differences.

3. Pass out copies of the relevant reproducibles, enough for each student to take home. As an assignment, have students complete the data discussed, being ready to report their results in class.

 

Wrap-Up: Results and Reflection

1. Begin by listing a range of student water usage totals as calculated in their audit assignment on the chalkboard or whiteboard. Guide students in determining the class average of daily water usage.

2. Lead a discussion of the students auditresults, water use, and availability. Use the following questions and answers as a guide:

a. Were you surprised by your daily personal water usage? Did you imagine that you used more or less water each day? How does your personal total differ from the class average?

b. How much of your total water was actually used and how much was wasted down the drain?

c.  How much more water do you use than what actually comes from the faucet? How is this water is used? Remind students that a large majority of water used in the U.S. is in agriculture and industry. For example, it takes thousands of gallons of water to raise a cow to make a pound of beef or a carton of milk, and nearly all of their food and drink required water to process. In addition, almost every product they use required water to make, transport, etc.

d. What factors affect the totals calculated today?

e. How would your audit look if you did it on a weekday vs. a weekend? Think about washing a car, doing laundry, running the dishwasher, etc.

f. What about summer vs. winter? Think about filling a pool, watering a garden or yard, etc.

g. How do you think your water usage compares to other people in the U.S.? Ex: Southwest is very dry, Northwest is very wet, urban vs. rural, poverty levels, etc.

h. How do you think your water usage compares to people in other countries? Consider climate, cost, availability, access, etc.

i. Conditions such as drought, pollution, rising population, and unequal distribution of natural resources threaten our water supply, even in the U.S. What might happen if we were faced with extreme water shortages? Cost would go up, our usage would have to go down, access would be less reliable, conservation practices would become more common, etc.

3. Remind your students that they have been learning about a little-understood, but very important, idea– that water and energy use are interconnected and the behaviors of individuals can have a major impact on water and energy conservation. Share these facts:

·        If one out of every 100 American homes were retrofitted with water-efficient fixtures, we could save about 100 million kWh of electricity per year. This would save 80,000 tons of greenhouse gas emissions, which is equivalent to removing nearly 15,000 cars from the road for one year![3]

·        If 1% of American homes replaced their older, inefficient toilets with WaterSense labeled models, the country would save more than 38 million kWh of electricity—enough to supply more than 43,000 households’ electricity for one month.[4]

·        A rain barrel can lower household water bills by about $35 a month in the summer.[5] Save hundreds of gallons of water each summer and year-round by using a rain barrel to collect water for watering your lawn, garden, and outdoor plants.

·        Don’t let water run unnecessarily when washing dishes, brushing teeth, showering or other tasks. Letting the faucet run for five minutes uses about as much energy as letting a 60-watt light bulb run for 14 hours![6]

·        Lower the temperature on your water heater to 120°F;for every 10ºF reduction in temperature, you can save from 3%–5% on your water heating costs.[7] You can also avoid using hot water unless it is necessary.

·        Fix leaks! A leak of one drip per second can cost $1 per month. At 60 drips per minute, you waste 8.64 gallons per day, 259 gallons per month, and just over 3,153 gallons per year. Think about all of that good, clean water just going to waste![8]

·        Encourage students to share other ideas about conserving water and/or energy.

4. Pass out an index card or a half-sheet of paper to each student. Explain that you will be asking them to respond to a series of questions. You will give them a minute or two to write their response to each question, but they should work silently. Questions:

·        What are the most important ideas that you learned from these activities that you want to remember?

·        What did you learn that you think everybody should understand and why?

·        What is one fact you plan to share with your friends and family?

·        What actions do you plan to take in your home?

·        What questions do these activities raise about your future?

·        If you had a chance to speak to a government or elected official about what you learned, what would you want to tell them?

5. Allow students to share their thoughts by asking them to read their responses to each question. Try to have every student contribute at least one idea during the discussion of the four questions. As they speak, record their ideas on large paper. End by highlighting themes that came out. Later, post their ideas on the classroom wall for all to read. Remind students about actions they can take to conserve resources.

 

Extension: Raising Public and Political Awareness

  1. Revisit the question, “If you had a chance to speak to a government or elected official about what you learned, what would you want to tell them?” and student responses in the Wrap-Up activity.
  2. Go over student answers and ideas. Discuss the pros and cons of various approaches and solutions. Have the class vote on their favorite(s) and/or choose one or more ideas that are the most practical. As a class, write letters to the applicable school, district, or government official explaining the issues and presenting ideas for solutions. You may also choose to start petitions or write letters to the editor of your school or community newspaper.

 

Extension: Hot ShowersCan We Save Energy and Water?

1. Ask students how many minutes they shower. Five minutes? Ten? Twenty or more? In this activity, they will calculate how much water they actually use when showering.

2. Pass out copies of Reproducible # 8 – Tracking Shower Time and Water Use. Tell them that you want them to track how many showers they take in a week and to time how long their showers last. Give them the dates of the week you would like them to gather data and have them record those dates on their sheet.

3. Explain that showerheads vary tremendously in the amount of water they use per minute. To make their results accurate, each student needs to calculate the flow rate of their showerhead. Go through these steps as they are outlined on the handout.

4. Ask your students to complete this handout as homework and announce the day they should bring their results to class for a discussion.

5. Discussion questions: 

·        What did you learn?

·        How many of you found your showerhead was a low-flow model, one that uses 2.5 gallons per minute or less?

·        How many of you found your showerhead was a very high-flow model, one that uses 7 gallons per minute or more?

·        In the class, what is the range of water used for showers each week?

·        How many people were surprised by how much (or how little) water they used for showers?

·        Given that most bathtubs are 40 – 80 gallons, at what point does it become more economical (and ecological) to take a bath instead of a shower?

6. Remind students about the connection between water and energy. The energy embedded in hot water not only includes the energy used to treat and transport water, it also requires further energy to heat it. Heating hot water with electricity is especially costly for families. In addition, the water that goes down the drain needs to be treated at the sewage treatment plant, and this requires more energy.

7. Ask students what three things people can do to save water and energy through showers? They can take shorter showers (or turn off the water while shampooing and shaving), they can take less steamy showers, and they can replace showerheads with more water-saving models. Would any students be willing to do one of all of these things? Why or why not?

 

Extension: Reducing Hot Water Use in the Home

1. Explain to your students that you’d like them to research some of the behaviors, new technologies and appliances that help to reduce the use of hot water. One of the specific ways students can save water and energy is to help reduce the amount of hot water used in their homes.

2. Divide your students into research groups. Assign each group a topic. Topics could include:

·        Compare the flow rates of old showerheads to new low-flow models.

·        Compare water usage in old washing machines to new energy-star models.

·        Why it is important to fix faucet leaks and how much water (and energy) can be lost when they are not fixed?

·        New faucet fixtures that save water (and energy!)

·        Ways to make hot water heaters more efficient.

·        List behaviors and actions that will have the most impact on reducing hot water usage at home.

3. The three sites listed below will provide a helpful start for your students. There are other useful items on the resource list for this lesson, but your students will certainly find more beneficial resources as they do their research.

·        http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=13050.

·        http://www.epa.gov/WaterSense/pubs/waterenergy.html.

·        http://www.energystar.gov/index.cfm?c=appliances.pr_appliances.

4. Have students present their findings to the class through a presentation or poster session.

 

CONCLUSION

Students were introduced to the important links between our energy use and water use. They learned where energy is used throughout the water treatment, delivery, and waste treatment systems, and read an article about the large amount of water consumed in the process of producing electricity and burning fossil fuels. At home, students conducted a personal and/or household water audit to determine how much water they use and how they could cut back, saving both water and energy. Finally, students began to consider how the links between water and energy may affect their future.

[1]“Benefits of Water Efficiency,” WaterSense. U.S. Environmental Protection Agency, http://www.epa.gov/watersense/water_efficiency/benefits_of_water_efficiency.html.

[2] “Exploring the Energy-Water Nexus: A Stakeholder Dialogue for Identification of Critical Issues,” National Renewable Energy Lab,

http://www.nrel.gov/analysis/workshops/water_nexus_workshop.html.

[3]“Benefits of Water Efficiency,” WaterSense. U.S. Environmental Protection Agency, http://www.epa.gov/watersense/water_efficiency/benefits_of_water_efficiency.html.

“Benefits of Water Efficiency,” WaterSense. U.S. Environmental Protection Agency, http://www.epa.gov/watersense/water_efficiency/benefits_of_water_efficiency.html.

[5]“Rain Barrel Survey Results,” DC Urban Gardeners, http://www.dc-urban-gardener-news.com/rain-barrel-roundup-the-s.html.

[6]“Benefits of Water Efficiency,” WaterSense. U.S. Environmental Protection Agency, http://www.epa.gov/watersense/water_efficiency/benefits_of_water_efficiency.html.

[7]“15 Ways to Save on Your Water Heating Bill,” Energy Savers Blog, U.S. Department of Energy, http://eereblogs.energy.gov/energysavers/post/15-Ways-to-Save-on-Your-Water-Heating-Bill.aspx.

[8]“15 Ways to Save on Your Water Heating Bill,” Energy Savers Blog, U.S. Department of Energy, http://eereblogs.energy.gov/energysavers/post/15-Ways-to-Save-on-Your-Water-Heating-Bill.aspx.