OBJECTIVE

Students will identify photovoltaic solar power as a source of energy. Students will explain what happens when a photovoltaic cell is shaded. Students will understand why we can’t rely solely on this resource for energy.

PURPOSE OF ACTIVITY

Read or Listen, Identify Details, Apply Skills

21st CENTURY SKILLS

Critical Thinking, Collaboration

COGNITIVE LEVEL

Strategic Thinking, Extended Thinking, Skills and Concepts

CLASS TIME

Four class periods of 45-60 minutes

• Day 1: Introduction and research
• Day 2: Building the prototype
• Day 3: Testing prototype and redesign
• Day 4: Testing of redesign and interpretation

MATERIALS

Materials listed are enough for one group of 3-4 students.

• Cardboard, poster board or stiff paper to construct the house
• House design templates – find templates at this website: https://www.template.net/business/paper-templates/paper-house-template/.
• Protractors – two per group
• Small solar panel
• 1 voltmeter per group
• Two sunny days to test the prototypes three times (at the start of the day, during lunch and near the end of the school day)
• Student sheet

PROCEDURE

Divide the students into groups of three or four. Allow students to design their houses based on the templates. Make sure you have stiff paper that will be able to hold the weight of the solar panel. The students will also need a square of poster board to place their house on as a base.

Day one: Introduction and research

Have students discuss their knowledge of solar panels – where they have seen them and how they work. After the discussion, let students come up with some questions they may need to know before they create a house that will hold a solar panel. Have them write down their questions. As a class, look at the questions the groups came up with.

Research: On the student worksheet, there are links that the students can click on and watch to learn how solar panels work and how they create energy. Students will need to take notes. Have the students work quietly on their own notes and designs.

Bring the students together in their groups. Ask them if there is something they would add or change to their model. As a group, determine which house design will provide the best solar solution. Where should the solar panels go?

Have the groups use their research to create a model that will meet the criteria and constraints. Make sure they realize that they only have a limited amount of time to build their prototype. The students will also need to have a look at what supplies are available for use. Groups must make a list of supplies. They will also need to have a detailed model with notes on the height of the house, the angle of the roof, where they are putting the solar panel and their prediction on how many watts of energy they will get.

Note: Some students may want to place their solar panel on the ground. If so, make sure they indicate at what angle the panel will be set.

Day two: Building your prototype

Students build their prototype.

Day three: Testing, analyzing and redesign

Teacher prep: Set up an area outside where the students can test their prototype. Make sure that each group has access to the voltmeters. The students will need ten minutes to test their prototype at least three times throughout the day. Suggested times would be first thing in the morning, around lunchtime and at the end of the day. The students will need time to redesign their prototypes and retest them.

Video on how to read a voltmeter: The Best Multimeter Tutorial (4:35)

Student groups can test their prototype, writing down the amount of energy they have created using solar energy. They will record the volts on the voltmeter. They will also need to record any observations they may see (example: angle is off, roof is too steep, roof is too weak, etc.).
Once the group has tested their prototype, the students need to answer the analysis questions.

Students will then get an opportunity to redesign and update their prototype. Explain that this is not a time to start over from the beginning. This is the time to look at their problems and use different ideas to come up with a solution. Allow time for the students to make changes to their prototype and test again. Record their data and observations on a data table.

Day four: Testing redesign and analyzing data

Allow students to test their redesigns and analyze the data.

What are some constraints to homeowners who wish to use solar energy?

Cost of solar panels, amount of electricity the panels can produce, number of days of adequate sunlight, the size of the homeowner’s roof.

Why is solar energy attractive to homeowners?

The energy source is free, solar energy produces little or no emissions while current energy sources do produce emissions, and solar energy costs less than other sources.

Natural gas is a resource used for many things. Natural gas powers many of the things people use every day. Despite its importance in our daily lives, few people probably stop to think what life would be like without natural gas. But we use natural gas to do many jobs for us every day – from heating our homes to powering our ovens.

OBJECTIVE

Students will illustrate the effect natural gas has on our daily lives.

PURPOSE OF ACTIVITY

Review, Identify Details, Communicate, Create

21st CENTURY SKILLS

Critical Thinking, Collaboration

COGNITIVE LEVEL

Strategic and Extended Thinking

CLASS TIME

15-30 minutes

MATERIALS

• Chalkboard or whiteboard

PROCEDURE

1. Ask the students to identify things in the classroom or in the school that use natural gas. Write these answers on the board. Ask students to continue identifying things at home that also use natural gas.
2. The students will write a story (or draw a picture) about everything they do all day that uses natural gas. Have them also write down how they would do these things if they did not have natural gas. (Example: cook food, heat their homes, etc.)
3. Present the stories to the class.

How important is natural gas to your daily life?

Natural gas is an integral part of daily life, since we use it in so many different ways.

How do you use natural gas at home, at school or all throughout your city?

We use it to cook, heat water, power vehicles, etc.

OBJECTIVE

Students learn that air contains water vapor and that water vapor can condense to form clouds and precipitation.

PURPOSE OF ACTIVITY

Review, Identify Details

21st CENTURY SKILLS

Critical Thinking

COGNITIVE LEVEL

Strategic and Extended Thinking

CLASS TIME

30 minutes

MATERIALS

• Large empty metal can
• Enough ice to fill the can
• Clear pitcher or beaker
• Water
• Food coloring
• White paper towel

PROCEDURE

Fill the metal can with the ice. Fill the pitcher with water and add a few drops of food coloring. Stir the contents to evenly distribute the food coloring.

Students should predict what will happen when the colored water is poured into the can of ice.

Pour the colored water into the can of ice and allow it to stand for a few minutes. After a few minutes, students should notice moisture on the outside of the can.

Lead a class discussion on the source of water on the outside of the can. Ask students to suggest ways to test their hypotheses and support their results with evidence. Students might suggest wiping the outside of the can with a white cloth or paper towel. No food coloring will appear on the cloth so students may infer that no water came from the inside of the can.

Explain to the students that there is water in the air around us. When water heats up, it turns into water vapor. This is called evaporation. Evaporation can also happen when wind blows over water. Puddles disappear because of a combination of wind and sun.

There is water vapor in the air next to the metal can. Once the ice and water are put into the can, the surrounding air cools and the water condenses onto the side. This is condensation. In a similar way, the water present in clouds will condense when the air temperature cools. The water vapor in the clouds turns into water droplets. The water droplets are heavier than the vapor and fall, or precipitate, back to the ground.

If the can were left out for several days, what would happen to the water?

Some of the water in the can would evaporate and return to the air.

What happens to this water?

It floats through the air and becomes a part of the atmosphere.

What happens to water in clouds?

It can condense and fall as rain or snow.

Solar Power

The surface of the Sun has a temperature of about 5,800 Kelvin (about 5,500 degrees Celsius, or about 10,000 degrees Fahrenheit). At that temperature, most of the energy the Sun radiates is visible and near-infrared light. At Earth’s average distance from the Sun (about 150 million kilometers), the average intensity of solar energy reaching the top of the atmosphere directly facing the Sun is about 1,360 watts per square meter, according to measurements made by the most recent NASA satellite missions. This amount of power is known as the total solar irradiance.

A watt is a measurement of power, or the amount of energy that something generates or uses over time. How much power is 1,360 watts? An incandescent lightbulb uses anywhere from 40 to 100 watts. A microwave uses about 1,000 watts. If, for just one hour, you could capture and re-use all the solar energy arriving over a single square meter at the top of the atmosphere directly facing the Sun, you would have enough to run a refrigerator all day.

The total solar irradiance is the maximum possible power that the Sun can deliver to a planet at Earth’s average distance from the Sun; basic geometry limits the actual solar energy intercepted by Earth. Only half the Earth is ever lit by the Sun at one time, which halves the total solar irradiance.

In addition, the total solar irradiance is the maximum power the Sun can deliver to a surface that is perpendicular to the path of incoming light. Because the Earth is a sphere, only areas near the equator at midday come close to being perpendicular to the path of incoming light. Everywhere else, the light comes in at an angle. The progressive decrease in the angle of solar illumination with increasing latitude reduces the average solar irradiance by an additional one-half.

Averaged over the entire planet, the amount of sunlight arriving at the top of Earth’s atmosphere is only one-fourth of the total solar irradiance, or approximately 340 watts per square meter.

Source: https://earthobservatory.nasa.gov/features/EnergyBalance/page2.php.

Biogas

Landfills can be a source of energy. Anaerobic bacteria that live in landfills decompose organic waste to produce a gas called biogas that contains methane.

Methane is the same energy-rich gas that is in natural gas, which is the fuel used for heating, cooking and producing electricity. Methane is colorless and odorless, and a very strong greenhouse gas. Natural gas utilities add an odorant (bad smell) so people can detect natural gas leaks. Landfill biogas can be dangerous to people or the environment. New rules require landfills to collect methane gas for safety and pollution control.

Some landfills simply burn the methane gas in a controlled way to get rid of it. But the methane can also be used as an energy source. Landfills can collect the methane gas, treat it and then sell it as a commercial fuel. It can then be burned to generate steam and electricity.

Landfill Gas Energy Projects

As of October 2011, 526 landfills have 563 operating gas-to-energy projects in the United States. California has the most landfill gas energy projects in operation (76), followed by Pennsylvania (39) and Michigan (36).

Source: https://zooidaho.org/documents/alternative-energy/EIA%20Biomass%20Energy.pdf

Underwater Food Chain

Plankton is defined as floating plants and animals that cannot move against the current under their own power. We usually refer to any floating, small or microscopic organism (plant or animal) as plankton.

Plankton is divided into phytoplankton (plant plankton) and zooplankton (animal plankton). Phytoplankton is made up of single-celled and multi-cellular green organisms that use photosynthesis to live and grow from solar energy, in much the same way plants do on land. Phytoplankton lives and dies floating around on the currents of the world’s oceans, bays and estuaries. Zooplankton includes a vast array of tiny animals that feed on phytoplankton and one another. Zooplankton includes many animals that never get very large, eggs of fish and marine invertebrates, and many larval forms of familiar sea creatures (crabs, lobsters, jellyfish) that leave the plankton as they mature.

Many types of marine animals feed by forcing sea water through filters to remove edible particles from the water. This method of capturing food is known as filter-feeding. Bivalves such as clams and mussels draw water into their body through a siphon, pass it through a series of filters and expel the water, digesting the microscopic organisms that were floating in the water. Baleen whales use their brush-like teeth to strain small shrimp, krill and fish from the sea water. Barnacles use a fan-like tail to scoop plankton from the water like a child might use a butterfly net on insects. All of these methods are types of filter-feeding.

Adapted from: https://www.dec.ny.gov/docs/administration_pdf/lpplankton.pdf.