This classroom activity introduces students to the context of the performance task. This ensures that students are not disadvantaged in completing the skills the task intends to assess. Contextual elements include understanding the situation of the task, potentially unfamiliar concepts associated with the situation or setting, and key terms or vocabulary students will need to understand in order to engage with the performance task. This classroom activity is also intended to interest the students in the task they are to complete. This activity should be easy to implement, and contains clear instructions. Please read through the entire classroom activity before beginning the activity with students. This will ensure that all classroom preparation is completed before the activity begins. Resources Needed: Chart paper, whiteboard, or chalkboard Markers or chalk One piece of paper and pencil for each pair of students Some method of displaying supplementary materials 1 Projector or some manner to share photographs Learning Goals: Students will understand the context of the key concepts related to the topic: o People can use different resources for electricity o There are various pros and cons to different energy sources o Different factors can decide which source of energy is the best Students will understand the key terms: o Renewable resources: resources that are naturally replenished on a human timescale o Non-renewable resources: a resource that does not renew itself at a sufficient rate for sustainable economic extraction in meaningful human timeframes o Fossil fuels: fuels formed by natural processes of buried dead organisms o Carbon footprint: the total amount of greenhouse gases produced to directly and indirectly support human activities, usually expressed in equivalent tons of carbon dioxide (CO2) Definitions are provided here for the convenience of facilitators. Students are expected to understand these key terms as they arise in the context of the task, not to be able to recite the definitions. 1 Facilitators can decide whether they want to display ancillary materials using an overhead projector or computer/smartboard, or whether they want to produce them as a handout for students. Copyright 2016 Key Data Systems 1
[Purpose: The facilitator's goal is to help students understand that people can use different resources for electricity, there are various pros and cons to different energy sources and that different factors can decide which source of energy is the best choice. This activity will allow students to be active participants as they further explore the concept of energy sources.] Note: The following section can be modified to accommodate various teacher-student interaction types such as a teacher-led discussion with the entire class, a teacher-student discussion for remote locations with a single student, or small groups. [Place the students into pairs. Give each group a piece of paper and a pencil.] Facilitator says: "Today, in preparation for your performance task, we are going to have a discussion about energy sources. Nowadays, everything seems to run on some form of electricity and we get that energy from different power plants. Different plants utilize specific resources and can pump out different amounts of energy. Does anyone know what some of these resources are?" [Write Energy Resources on the board or on chart paper and record student responses beneath it. For students with visual impairments or reading disabilities, say Energy Resources aloud.] Wind energy Solar energy Hydroelectricity Coal Petroleum Nuclear power Geothermal energy Natural gas [Add any of the above responses that are not said by the students. Group answers together whether they are renewable or non-renewable resources.] Facilitator says: "These resources are classified as either renewable or non-renewable." [Draw a line between the two groups, draw a circle around each group, or do something that differentiates the groups.] Facilitator says: "Renewable resources are resources that are naturally replaced before people can use them all up. Non-renewable resources are resources that cannot be replaced at the current rate of consumption. Which group do you think is renewable and which is non-renewable?" [Call on student volunteer.] Copyright 2016 Key Data Systems 2
Facilitator says: "Wind energy, solar energy, hydroelectricity, and geothermal energy are examples of renewable energy. They are renewable because wind is powered by the Sun, which will keep shining for the next 6.5 billion years. Water will keep flowing down because of gravity and the water cycle, and as long as the Earth has magma, we will have geothermal reserves." [Display Figure 1: Energy Chart or distribute it to students as a handout.] Facilitator says: "With your partner, discuss what you know about energy that comes from these resources." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Energy Renewable Green and environmentally friendly Resources can be found anywhere in seemingly infinite amounts Maintenance costs are relatively cheap Generally inconsistent in energy production Initial costs of power plants are high Generally produces less energy than non-renewable power plants Cost of production remains constant Non-renewable Cheap and easy to use Can easily convert one type of energy to another Produces more power than renewable energy Finite resources Resources will only get more expensive as supply runs out Releases toxic gases when burnt Contributes to global warming [Record the information in Figure 1 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] Facilitator says: "Let's start talking about specific sources of energy." [Facilitator displays Figure 3 on the projector or some other display.] Facilitator says: "Does this look familiar to anyone? This is a solar panel, which can harness the power of the Sun. That grossly incandescent ball of nuclear fusion in the sky delivers about 1360 watts per square meter." [Facilitator displays Figure 4 on the projector or some other display.] Facilitator says: "That means if you collect all the energy from sunlight within a square meter and put that in a battery, you can power thirteen 100 watt light bulbs for an hour. Of course, that is only if you have 100% efficiency with your collection. That means none of the energy is released as heat or reflected off." Copyright 2016 Key Data Systems 3
Facilitator says: "There are several ways people can use the energy from the Sun. The one you most likely know is through the use of photovoltaic systems. These are the solar panels that you saw earlier. This involves directly absorbing sunlight and turning that into electricity. Another way is through solar thermal systems." [Facilitator displays Figure 5 on the projector or some other display] Facilitator says: "This is a picture of a field of mirrors that focus sunlight into a tall tower. Inside that tower is basically a big bucket of water. The sunlight heats up the water in the tower, turning it into steam, which turns a turbine as it flows out. That turbine generates electricity." Facilitator says: "Solar power is great for providing power to places that can't get it from a national grid. Laying solar panels is a lot cheaper than laying down power lines. They are also low maintenance, you just have to keep the panels clean and free of dust." [Display Figure 2: Energy Source Chart or distribute it to students as a handout.] Facilitator says: "Solar power is not perfect, however. I would like for you to discuss with your partner about the possible pros and cons about solar energy. Consider how solar power works and what it needs to work. Let's avoid including facts we already covered in the first table." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Solar Energy Pros Quiet Can provide power to locations not connected to a national grid Low maintenance Cons Doesn't work without direct sunlight (cloudy, dusty, or at night) Power output depends on light intensity Note: If a student chooses a fact already used in Figure 1, explain that those traits cover all or most sources of renewable energy and do not need to be repeated. [Record the information in Figure 2 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] Facilitator says: "In addition to our appliances, the Sun also powers an important part of nature: wind. Using wind turbines, humans can generate electricity with little to no carbon footprint." [Facilitator displays Figure 6 on the projector or some other display.] Facilitator says: "The wind turns the blades on the turbine and a generator inside it converts the kinetic energy into electrical energy. It works just like steam power except wind is turning the turbine, rather than steam." Copyright 2016 Key Data Systems 4
Facilitator says: "Even if a breeze is blowing, however, turbines may not generate power. Turbines need wind with at least a certain speed before it can generate power. Usually, this is around 7 to 10 mph. The faster the wind, the greater the power. That is why most wind turbines are more than 200 feet tall. The wind is faster and less turbulent at that height. With this in mind, what do you think happens during a storm?" [Call on student volunteer.] Facilitator says: "You would think it would generate a great deal more power, but wind turbines actually shut down during high wind speeds to prevent damage." Facilitator says: "Wind power has its own problems too. It is still expensive--despite being the cheapest renewable power source--and wind turbines have been known to kill many birds and bats. Some people also find wind turbines to be annoying. They do not enjoy the view of wind farms nor do they enjoy the noise coming from the turbines." [Display Figure 2: Energy Source Chart or point the students' attention to the handout.] Facilitator says: "Let us summarize what we know about wind power. With your partner, discuss what details would go into this table." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Wind Energy Pros Cheapest renewable power source Incredibly space efficient Prices continue to drop rapidly Highly profitable investments Cons Wind provides a constantly fluctuating power output High initial costs Can threaten wildlife Noisy Some people do not like how wind turbines look Note: If a student chooses a fact already used in Figure 1, explain that those traits cover all or most sources of renewable energy and do not need to be repeated. [Record the information in Figure 2 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] [Facilitator displays Figure 7 on the projector or some other display.] Facilitator says: "Does anyone recognize this structure in the picture? This is the Hoover Dam on the Colorado River, and using the force of the water flowing down, the Hoover Dam produces around 2080 megawatts. That is enough to power almost 200 homes for an entire year." [Facilitator displays Figure 8 on the projector or some other display.] Copyright 2016 Key Data Systems 5
Facilitator says: "The Hoover Dam provides power though hydroelectricity. You can see in the picture, water flows through that small dam. It uses the force from flowing water to move turbines inside the dam to generate electricity. Right now, hydropower is the most widely-used source of energy in the world. Can anyone imagine why?" [Call on student volunteer.] Facilitator says: "Hydropower is one of the most widely used power source because not only is it reliable, it is also flexible. Unlike solar or wind power, hydropower is constant and even controllable. Hydropower plants usually have gates that can change how much water flows through. This changes how much energy the plant produces. Hydro plants can also be any size needed, so they can work on many sources of running water. This applies to oceans as well. Using the power of waves, people can generate electricity. Hydro plants start and shut down quickly. Unlike other power plants that could take hours to start, hydro plants only need minutes. This makes hydropower great for covering emergency situations." Facilitator says: "Hydropower has its own compromises, however. Not only do hydropower plants need lots of space, they can also affect the environment by preventing nutrients, organisms, and water from flowing downstream. This could potentially disrupt ecosystems in the area. People could also be relocated for dam construction or if they live in an area of possible flooding." [Display Figure 2: Energy Source Chart or point the students' attention to the handout.] Facilitator says: "Summarize this section with your partner and share your results." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Hydropower Pros Provides constant power Power output is controllable Quick start and stop Plant size can vary Cons Can disrupt ecosystems Needs lots of space Threat for people Drought could affect production of electricity Note: If a student chooses a fact already used in Figure 1, explain that those traits cover all or most sources of renewable energy and do not need to be repeated. [Record the information in Figure 2 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] [Facilitator displays Figure 9 on the projector or some other display.] Copyright 2016 Key Data Systems 6
Facilitator says: "The last of the big renewable energy sources is geothermal energy. This involves harnessing the heat that naturally comes from the earth. Geothermal plants work like non-renewable power plants. The process involves heat and water. Can you guess what happens?" [Call on student volunteer.] Facilitator says: "Geothermal plants use heat from the earth to boil water and use the steam to turn turbines. Since this process involves only heat and water, most of the exhaust from geothermal plants is just water vapor. Excess water is then pumped back into the ground to replenish the reservoir. Sometimes though, geothermal plants can release toxic gases from the ground." Facilitator says: "Although it produces a lot of clean energy, locations with geothermal energy are extremely limited. Most of the geothermal plants in the US are in the west, near Hawaii and Alaska. Heat from geothermal locations can be pumped directly into houses for heating but this is extremely local. Do not expect geothermal energy to heat a faraway house." Facilitator says: "Unlike other types of renewable energy, geothermal energy has the potential to be non-renewable. Without careful maintenance, geothermal reservoirs could run out of water or the water we pump back into the earth could cause the area to cool down." [Display Figure 2: Energy Source Chart or point the students' attention to the handout.] Facilitator says: "With your partner, summarize what you know into the chart." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Geothermal Energy Pros Cons Provides constant power Economically exploitable locations Zero carbon emissions No fuel required (costs remain constant) are limited Accessing geothermal energy usually requires deep drilling High maintenance for renewability Toxic emissions Note: If a student chooses a fact already used in Figure 1, explain that those traits cover all or most sources of renewable energy and do not need to be repeated. [Record the information in Figure 2 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] Copyright 2016 Key Data Systems 7
Facilitator says: "In contrast to renewable energy, non-renewable energy sources produce much more energy. Most of the power on earth comes from non-renewable resources and most of these resources are fossil fuels, which are carbon based fuels that come from the remains of dead plants and animals after decomposing for millions of years. Does anyone know which non-renewable resource is the most used?" [Call student volunteer.] Facilitator says: "It is coal." [Facilitator displays Figure 10 on the projector or some other display.] Facilitator says: "Coal is really cheap and plentiful. It also has a high load factor, which means people can use most of the energy that coal contains. Renewable resources have a low load factor, which means people cannot use much of the potential energy they have. In addition to that, coal is also a mature industry that generates income for the United States, which is a net exporter of coal." Facilitator says: "Unfortunately, it is extremely dirty. Even clean coal, coal with most of the CO2 stripped out, is still the most polluting fuel source in use. The byproduct of burning coal, coal ash, was discovered to be more radioactive than nuclear waste. Acquisition of coal is also dangerous as coal mining is considered one of the most dangerous jobs on Earth and the process at which coal is mined can damage environments." [Display Figure 2: Energy Source Chart or point the students' attention to the handout.] Facilitator says: "With your partner, summarize what you know into the chart." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Coal Energy Pros Cheap Plentiful reserves Provides trade income to the United States Cons Highest polluting fuel source Coal mining is dangerous Coal mining damages environments Byproducts are radioactive Note: If a student chooses a fact already used in Figure 1, explain that those traits cover all or most sources of renewable energy and do not need to be repeated. [Record the information in Figure 2 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] Copyright 2016 Key Data Systems 8
Facilitator says: "Unlike the other sources of energy, petroleum's main use is not for generating electricity. 72% of oil goes into fuel for transportation, which produces a large chunk of air pollution statistics, while only 1% is used for electricity. Oil is easier to extract from the ground than coal and is easier to handle, store and transport. A problem for oil is that extraction of oil can affect habitats. One of the biggest problems, however is an oil spill, which can effectively destroy marine habitats." [Display Figure 2: Energy Source Chart or point the students' attention to the handout.] Facilitator says: "With your partner, summarize what you know into the chart." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Petroleum Energy Pros Cons Easy to transport Oil spills are exceptionally damaging Easy to extract Versatile in use Cleaner than coal in the event of a spill The U.S. is highly dependent on oil from foreign countries Note: If a student chooses a fact already used in Figure 1, explain that those traits cover all or most sources of renewable energy and do not need to be repeated. [Record the information in Figure 2 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] Facilitator says: "Out of all the fossil fuels, natural gas is the cleanest. It consists mostly of methane but some amounts of other hydrocarbon gases, nitrogen, and carbon dioxide. It is usually found deep underground and when recovered, is the hardest to transport, since it is a highly combustible gas, which means it explodes. Pipelines that transport natural gas are often protected from bad weather unlike coal and oil transport systems, but management of the pipelines can be costly." Facilitator says: "Natural gas plants burn the gas and the hot exhaust turns a turbine. The heat from the combustion is also used to make steam to drive a steam turbine." [Display Figure 2: Energy Source Chart or point the students' attention to the handout.] Facilitator says: "With your partner, summarize what you know into the chart." [Give students one to two minutes to discuss. Choose students to share some of their answers.] Copyright 2016 Key Data Systems 9
Natural Gas Energy Pros Cons Cleanest fossil fuel Colorless, odorless, and tasteless; No residue like soot or ash makes finding leaks difficult Fuel is non-toxic Pipelines can be expensive Note: If a student chooses a fact already used in Figure 1, explain that those traits cover all or most sources of renewable energy and do not need to be repeated. [Record the information in Figure 2 or have students record the information on their handout. For students with visual impairments or reading disabilities, repeat the information aloud.] Facilitator says: "In your performance task, you will be learning about more things about sources of energy. The work you did today should help prepare you for the research and writing you will be doing in the performance task." [Collect all notes from students and remind them that they cannot be used during the performance task.] Copyright 2016 Key Data Systems 10
Resource Documents Figure 1. Energy Chart Renewable Energy Non-renewable [Picture Description: "The chart should be used to complete the first activity mentioned in the document."] Copyright 2016 Key Data Systems 11
Figure 2. Energy Source Chart Energy Sources Pros Cons Solar Energy Wind Energy Hydropower Geothermal Energy Coal Energy Petroleum Energy Natural Gas Energy [Picture Description: "The chart should be used to complete the second activity mentioned in the document."] Copyright 2016 Key Data Systems 12
Figure 3. Picture of Solar Panel [Picture Description: "This picture shows one single solar panel on a roof."] Figure 4. Display Solar Power [Picture Description: "This picture shows the power the Sun can produce in one square meter of space."] Copyright 2016 Key Data Systems 13
Figure 5. Mirror Reflectors [Picture Description: "This picture shows a field of mirrors to focus solar power."] Figure 6. Wind Turbines [Picture Description: "This picture shows a field of wind turbines, focusing on four turbines."] Copyright 2016 Key Data Systems 14
Figure 7. Hoover Dam [Picture Description: "This picture shows the Hoover Dam, on the Colorado River."] Figure 8. Hydropower [Picture Description: "This picture shows the how power is generated through water."] Copyright 2016 Key Data Systems 15
Figure 9. Geothermal Plant [Picture Description: "This picture shows a geothermal energy plant."] Figure 10. Coal Plant [Picture Description: "This picture shows a coal energy plant."] Copyright 2016 Key Data Systems 16