Hands-on Activity: Rolling Blackouts & Environmental Impact – What Are Our Electricity Options?

Contributed by: K-12 Outreach Office, Worcester Polytechnic Institute

A distant skyline of entirely dark skyscrapers against a sunset pink sky.
What happens when there is a blackout?
copyright
Copyright © U.S. Department of Homeland Security http://www.dhs.gov/power-hungry-prototyping-replacement-ehv-transformers

Summary

Through this activity, students come to understand the environmental design considerations required when generating electricity. The electric power that we use every day at home and work is usually generated by a variety of power plants. Power plants are engineered to utilize the conversion of one form of energy to another. The main components of a power plant are an input source of energy that is used to turn large turbines, and a method to convert the turbine rotation into electricity. The input sources of energy include fossil fuels (coal, natural gas and oil), wind, water, nuclear materials and refuse. This activity focuses on how much energy can be converted to electricity from many of these input sources. It also considers the impact of the by-products associated with using these natural resources, and looks at electricity requirements. To do this, students research and evaluate the electricity needs of their community, the available local resources for generating electricity, and the impact of using those resources.
This engineering curriculum meets Next Generation Science Standards (NGSS).

Engineering Connection

Creating power plants, harnessing input energy and distributing energy to power the devices in our world is important to us everyday and requires many types of engineers to accomplish it. Mechanical, structural, chemical and electrical engineers design power plants to supply energy. The input energy necessary for power plants is worked on by mining, petroleum, ocean and environmental engineers. These engineers from different fields combine their specialty expertise to find solutions to our energy challenges.

Pre-Req Knowledge

A familiarity with energy problems and energy resources. Assign the attached Preparation Worksheet as homework before the activity. (Allow ~2 hours to complete the assignment.)

Learning Objectives

After this activity, students should be able to:

  • Make an assessment of systems to meet needs.
  • Explain the role of society in the development and use of technology.
  • Follow the steps of the design process to brainstorm, research, develop a model and communicate the results.

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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.

  • Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Apply geometric methods to solve design problems (e.g., designing an object or structure to satisfy physical constraints or minimize cost; working with typographic grid systems based on ratios). (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Selecting resources involves trade-offs between competing values, such as availability, cost, desirability, and waste. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Making decisions about the use of technology involves weighing the trade-offs between the positive and negative effects. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Humans can devise technologies to conserve water, soil, and energy through such techniques as reusing, reducing, and recycling. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • When new technologies are developed to reduce the use of resources, considerations of trade-offs are important. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Humans devise technologies to reduce the negative consequences of other technologies. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Decisions regarding the implementation of technologies involve the weighing of trade-offs between predicted positive and negative effects on the environment. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Energy can be grouped into major forms: thermal, radiant, electrical, mechanical, chemical, nuclear, and others. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Energy resources can be renewable or nonrenewable. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
Suggest an alignment not listed above

Materials List

  • poster board
  • markers, pens, pencils
  • Reference Sheet 1
  • Worksheets 1 and 2
  • (optional) Internet access for research

Introduction/Motivation

Have you ever heard of a "rolling blackout"? (Listen to student ideas.)

In certain sections of the US, the amount of electricity that is available is not enough to meet the requirements of the area. This results in what are called "rolling blackouts" that impact all citizens and businesses. A rolling blackout is an intentionally-engineered electrical power outage in which electricity delivery is stopped for non-overlapping periods of time over geographical regions. Rolling blackouts are a last-resort measure used by an electric utility company in order to avoid a total blackout of the power system. They are usually in response to a situation in which the demand for electricity exceeds the power supply capability of the network.

A silouette of a power station and two large transformer towers connected by wires, against a background of a sunset sky.
copyright
Copyright © U.S. Department of Homeland Security http://www.dhs.gov/power-hungry-prototyping-replacement-ehv-transformers

Today, you will be acting as energy consultants for the planning board of a the HMT Corporation, which is going to build a new hospital in your community. They want to make sure that the new hospital will not be impacted if an energy crisis arises. To do this, the hospital wants to have its own power plant. So, they need to know (best estimate) what its electricity requirements will be when the hospital is operating at full capacity.

For you, a critical part of the consultant work will focus on predicting needs, resources, and impact around the projected electrical power needs of this new hospital.

In certain sections of the US, the amount of electricity that is available is not enough to meet the requirements of the area. This results in rolling blackouts that impact all citizens and businesses. The HMT Corporation is going to build a new hospital in your community. They want to ensure that the hospital is not impacted if an energy crisis arises. In order to do this, the hospital wants the hospital to have its own power plant. They need to know what the electricity requirements will be for the hospital when it is operating at full capacity. The students will act as energy consultants for the planning board of the hospital. A critical part of the consultant work will focus on predicting needs, resources, and impact around the projected electrical power needs of this new hospital.

Vocabulary/Definitions

blackout: A power failure.

brownout: A reduction in available electricity level due to high demand.

rolliing blackout: A rolling blackout, also referred to as load shedding, is an intentionally-engineered electrical power outage in which electricity delivery is stopped for non-overlapping periods of time over geographical regions. Rolling blackouts are a last-resort measure used by an electric utility company in order to avoid a total blackout of the power system. They are usually in response to a situation in which the demand for electricity exceeds the power supply capability of the network. Source: Wikipedia

turbine: An engine driven by the pressure of steam, water or air pushing on curved blades.

Procedure

Background

Electricity is vital to our everyday life. We assume that there will continuously be enough for us, but this is not always true. Every power plant has an upper limit to the amount of electricity it can generate. If the demand is greater than the supply, then brownouts and blackouts occur. As a population grows, the demand for electricity increases.

New power plants can be built to help meet the demand. Each power plant requires a source of input energy that is then converted to electricity. This conversion is most often done by creating steam that is driven through large, fan-like turbine blades. The steam causes the blades to rotate, and spin the shaft on which they are connected. The other end of the shaft generates electricity using the rotation and magnetic fields.

The input energy can be fuel, such as coal, oil or natural gas. Burning the fuel heats water to create the steam for the turbines. Fossil fuels are non-renewable energy resources that create various types of pollution when burned. Solar energy is also used to heat water and create steam for the turbines. Since it does not have to be burned, no polluting by-products are created. However, solar energy is not very efficient for this process. The energy given off from the splitting of atoms during nuclear fission is another input source for creating the steam. Nuclear power generates radioactive by products during the fission process. Geothermal energy from within the Earth can be used to heat the steam that spins the turbine blades. But, very few locations around the world have high enough geothermal temperatures to be suitable as the input energy.

There are also ways of generating electricity without using steam to spin turbine blades. Hydropower uses water to spin turbine blades. Usually a dam is required to maintain the water height, and this impacts the water life in the area as fish can no longer travel upstream.

Before the Activity

Have students complete the Preparation Worksheet for homework to gain a better understanding of the nation's energy problems and the types of energy resources available.

With the Students

Part 1: Establish the Baseline – Who needs electricity, and how much do they need?

  1. Divide the class into groups and hand out Worksheet 1 to each group. Lead a discussion about who uses electricity. Which category of users (home, transportation, businesses and industry) is the largest electricity consumer? Which group uses the least amount? What is their justification for how these compare?
  2. Have each group estimate on Worksheet 1 the percentage of electricity used by the four types of users (home, transportation, business, industry).
  3. Compare the predictions of each group. As a class, decide if you want to use the average value from the predictions for all the groups, or if groups want to use their own predictions. These estimates will be contrasted to actual numbers gathered by the groups.
  4. If you have Internet access, have groups research the actual average breakdown for each of the groups. If internet access is not available, or time does not permit, use the values provided on the attached Leaders Resource Page.
  5. Have the groups use the personal electricity data they have brought with them. What is the average kW/hr use for the group? Share this information to determine kW/hr average for the entire class.
  6. Discuss the resulting average and how it might vary over the course of a day, month and year. Does an overall group consensus on a peak demand time for electricity exist? Does it vary based upon the type of user? Does it vary based upon the location in the country?

Part 2: What are our resources for creating electricity?

  1. Explain that the teams have been hired by the HMT Corporation to estimate the power requirements of a new hospital when it operates at full capacity. The hospital is being designed to accommodate 500 patients plus all the support staff. Given that a hospital is like a small community with similar power needs for the basic four groups (home, transportation, business, industry), determine the resources of your locality that can be used for the hospital power plant. What are the impacts of your recommendation?
  2. Reinforce that the hospital is being considered for a neighboring community with resources similar to yours. Discuss the source of the electricity in your town. What is the input source of energy? Do you have other options for energy that are readily available? Create a list on the board of student suggestions.
  3. Present the students with the current town/hospital statistics provided on the Leader's Resource Page OR provide them with values that more closely represent a local community in your area.
  4. Change the groups so that there are now 2 or 3 larger groups. Have each group begin working as individual consulting reams for the HMT Corporation. Pass out Worksheet 2, which outlines the objectives, and Reference Sheet 1 with energy conversion efficiencies.
  5. Have groups present their proposals, including discussions of why they selected the energy sources they chose. Do they feel that their suggestions are worth pursuing? Lead a discussion on the trade-offs required for any of the choices. Every one of them has some impact on the environment.
  6. Reflect with the students how they approached the problem as engineers (research, idea generation, analysis, solution recommendations, etc.).

Attachments

Investigating Questions

  • What things in your home use electricity? (So many! For our day-to-day comfort: heating and air conditioning, hot water for showers and dish washing, lights, TV, stereo, stove, oven, computer, washing machine, dryer, kitchen appliances, vacuum cleaner, phone recharger, fans and clocks.)
  • How could we reduce the demand for electricity? (Conserving how much electricity we use and purchasing items that are designed to be more energy efficient.)

Assessment

Pre-Activity Assessment: Make sure that all students complete the Preparation Worksheet (perhaps as homework) before beginning the activity. Allow ~2 hours for completion.

Activity Embedded Assessment: Observe student participation within groups.

Post-Activity Assessment: Grade or critique the group proposals, especially looking at students' reasoning for why their recommended solutions are worthwhile.

Activity Extensions

Assign students to research how many power plants are in your state. What is their total electrical output? What do they do for their source of energy? How might this affect your state in the long run?

Activity Scaling

  • For lower grades, provide energy consumption statistics.
  • For upper grades, have teams research energy consumption for your specific town or region.

References

U.S. Energy Information Administration. http://www.eia.doe.gov

Brain, Marshall and Robert Lamb. "How Nuclear Power Works." HowStuffWorks. Accessed 2007. http://www.howstuffworks.com/nuclear-power.htm

Copyright

© 2013 by Regents of the University of Colorado; original © 2007 Worcester Polytechnic Institute

Supporting Program

K-12 Outreach Office, Worcester Polytechnic Institute

Last modified: May 10, 2017

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