Hands-on Activity Optimize!
Cleaner Energy Options for Rural China

Learning Objectives

After this activity, students should be able to:

• Explain what optimization means (to consider a variety of factors and inputs and find the best solution).
• Explain three challenges facing families in rural China (poverty, lack of access to education, lack of access to health care, environmental pollution, use of solid fuels leading to indoor air pollution).
• Describe three solutions engineers design to help rural families use cleaner energy for heating and cooking (biogas digesters, solar hot water systems, improved cookstoves).

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• pencil
• Scatter Plot Worksheet
• Optimization Worksheet

Worksheets and Attachments

Pre-Req Knowledge

Students should be able to choose options from a table, find the largest or smallest number in a set, and add sets of numbers in the thousands.

Introduction/Motivation

(Lead into this activity using the Introduction, slide presentation, and energy game provided in the associated lesson, Rural Energy in China: How Can Engineers Make a Difference?))

(Begin by asking the pre-activity questions in the Assessment section.)

In our lessons and activities so far, you've already learned about some of the environmental challenges facing China. You've learned about outdoor and indoor air pollution, about five types of renewable energies, and some great ways that kids and adults can save energy through energy efficiency. We've also talked about how different types of houses are more suitable for certain climates in China. Today we're going to learn about how engineers help people in the villages of China use cleaner energies to reduce their exposure to indoor air pollution and help their health. Engineers can make a big impact in helping people be healthier. That's one of the most wonderful things about engineers — how they can make a practical difference to change people's lives for the better!

Today, you will practice optimizing. You will work in engineering teams to optimize the best solution to help rural families in China use cleaner energy for cooking their meals and heating their homes. Do you remember what we mean by optimization? Optimization means to consider all the factors involved in solving a problem, and choose the best solution. Optimization often includes making a number of trade-offs. For example, when engineers want to help people who do not have much money, they might not be able to choose the best solution because the people may not be able to afford it. So, they have to choose a solution that is good, but that people can afford. Are you ready? Let's get started!

Procedure

Background

One method that engineers frequently employ in decision making is optimization. Optimization involves carefully weighing all the costs, benefits and drawbacks of various options to choose the best one for a given situation. Engineers working in developing communities consider many important factors when thinking about solutions that may be effective in bringing cleaner energy, sanitation or clean water to people in need. Factors that might need to be optimized include cost of implementation, emissions and other types of pollution, user functionality, operation and maintenance costs, expense to the community, types of supplies and equipment used, and other sustainability issues.

If students need a little clarification to understand the concept of optimization, hold a short discussion in which you discuss everyday and engineering scenarios that require optimization. Example scenarios:

• If you are making a peanut butter and jelly sandwich, you need to optimize the amount of jelly. Too little and you cannot taste the flavor; too much and it squishes out everywhere.
• You can wear more sweaters in the winter to stay warm and keep your heating bills low, but you can end up looking like a teddy bear if you wear 10 sweaters. What is the optimal balance between extra clothes, saving money, and not looking like a bear?
• We like cars with sunroofs, but cars must have enough steel in them to be strong enough to withstand the forces of traveling at high speeds and protecting people in crashes. So engineers design cars to optimize the area of the sun roof and strength of the roof.
• Engineers create playgrounds so kids can explore and have fun, but they also want the kids to stay safe. So they design playgrounds to balance adventure with safety.
• Engineers often work on big projects that are expensive, but they also have to try to stay on their timeline and get the job done by the deadline. If they want to finish more quickly, they might have to spend more money, but they also need to stay on budget, so they optimize between time and money.
• While farmers in the past used biomass to a great extent, the use of coal in rural areas in China is increasing. China is already struggling with significant air pollution, and the increased emissions from rural coal use only exacerbate the problem. However, coal is one of the least expensive energy options, so if we'd like farmers to use biomass in a sustainable way, we need to make sure that it is equal to or less than the price of coal.

Before the Activity

• With students, review content in the associated lesson, including its PowerPoint presentation.
• Make copies of the Scatter Plot Worksheet and Optimization Worksheet.
• Review the worksheet answers.

With the Students

1. Show students the worksheets and explain how to complete them.
2. Assign partners or let students self-select into teams of two.
3. Give students time to go through the worksheets in their groups.
4. Assist students with the worksheets as needed. Students may especially need help with graphing the points on the Scatter Plot Worksheet.
5. Review the Scatter Plot Worksheet as a class.
6. Review the Optimization Worksheet together as a class.
7. If time allows, write each teams' total cost and total emission level results on the board. Have each team describe how it came to decide on the best solution to help a family use cleaner energy for cooking and heating.
8. Discuss as a class why each group may have different answers for total cost and total emission levels (as described in the Assessment section). This is a key part of optimization. Based on how teams make decisions, different groups (and in real life, different teams of engineers) may optimize differently and find different solutions.
9. Administer the Post-Unit Quiz and creative reflection wrap-up assignment; see the Assessment section.

Vocabulary/Definitions

non-solid fuels: Liquid or gaseous fuels such as electricity, propane and gas.

optimization: Considering a variety of factors and choosing the best solution for the situation.

solid fuels: Non-liquid fuels such as coal, biomass, wood, dung or dried plant material. In China, they also burn straw, rice husks, corn husks corn stalks and corn cobs. Briquettes are cylindrical pieces of charcoal with holes in the middle, known as "honeycomb" coal that are often used to fuel cookstoves; their mix of clay and coal burns very dirtily.

Assessment

Pre-Activity Assessment

Opening Discussion: How Do We Cook at Home?: Talk with the students about the types of energy they use at home. Do they know where their energy comes from? Talk about how different types of energy are cleaner than others.

Activity Embedded Assessment

Worksheet Observation and Assistance: Assist students and talk with them individually as they work on their worksheets in groups. Use the Scatter Plot Worksheet to talk about how engineers use graphs as a way to pictorially represent the data they collecting and examining. The saying, "a picture is worth a thousand words," is certainly true when it comes to graphs! Encourage students to clearly label each point on their graphs. Also notice and compliment good engineering teamwork. Collect and grade worksheets to gauge student comprehension of the subject matter. Alternatively, write worksheet results in a table on the classroom board to provide an overview for discussion of options selected by different groups.

Post-Activity Assessment

Who Has the Lowest Answer? As a class, take turns reviewing each teams' answers. See who has the lowest answer in terms of cost, and who has the lowest answer for total emissions. Write the answer for cost and emissions for each team on the classroom board. You may find that students argue about which is most important — lower costs or lower emissions — which provides a great jumping-off place for a discussion on how engineers often have to make difficult choices. Usually, more than one good solution exists to solve engineering challenges (hence the phrase, "open-ended design"). Talk about the concept of trade-offs (optimization). Engineers must be realistic about which options are feasible for people, and may need to make trade-offs between which energy source would be idea for people to use vs. what is available, appropriate and affordable for a specific community.

Unit Summary Assessment

Quiz & Reflection: Gauge the impact of the curricular unit on students' learning by administering a Post-Unit Quiz and a creative reflection wrap-up assignment after concluding this lesson/activity set. See a description and the quiz attachment in the Assessment section of the Environmental Challenges in China unit.

Investigating Questions

What kind of energy do you use for cooking in your house?

What are some ways that engineers help people in developing communities?

How would you feel if the energy you used for cooking dinner made you sick?

Troubleshooting Tips

Younger students may be challenged in adding the numbers together and conceptualizing the idea of optimization. If this is the case, do the worksheets and discuss as a class.

Activity Extensions

Have students research how people in developing communities in Africa or India use fuel for cooking and heating. What sorts of cleaner options are used in these regions?

Work with other teachers in your school to connect what students are learning to other subject areas, such as art, mathematics, social studies, geography and history. China is a fascinating country with a long history and intricate culture and myriad ways exist to incorporate every subject into the study of China. Additionally, energy use may well be the defining issue of these students' lifetimes, and it is worth taking time to ponder their roles as current and future energy consumers in a global landscape.

Assign students to write two-page research papers on challenges facing families in rural China and ways that engineers are designing and implementing solutions to make a difference.

Activity Scaling

• For lower grades, conduct and review the worksheets as a class.
• For upper grades, talk about engineering criteria and constraints engineers must consider when designing solutions for developing communities, and brainstorm other scenarios in which engineers are required to optimize (begin with the examples provided in the Procedure > Background section).

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.