Bell Ringer

Instructions: Select one of the Bell Ringers for students to reflect on and answer.

Vocabulary

Instructions: Go over important terms and their definitions before watching the Science of Wind video. Student vocabulary list can be found in the Student Guide and Science of Wind – Starter Pack.

Quiz

Instructions: Review key concepts after watching the Science of Wind video. The Student Guide and Science of Wind – Starter Pack contain the quiz.
Answer Key: Q1:B Q2:B Q3:A Q4:B

Reading and Extended Reading

Instructions: Provide students with the Science of Wind – Reading or Extended Reading info sheet for an in-depth exploration of the topic.

Reading Answer Key

1. The Sun heats parts of the Earth differently.
2. Sails for boats or grinding grain with windmills.
3. The blades spin and make electricity.
4. Over 300 feet.
5. A group of turbines that make electricity.
6. In oceans or big lakes.
7. It doesn’t pollute the air or water.
8. They can hurt birds and bats.
9. Fiberglass or other strong materials.
10. 20 to 25 years.

Extended Reading Answer Key

1. Uneven heating of Earth’s surface causes wind
2. Sailing ships and grinding grain with windmills.
3. Blades, tower, nacelle.
4. 6-9 miles per hour.
5. Blades spin a rotor connected to a generator.
6. Stronger, more consistent wind and fewer people nearby.
7. No pollution, no fuel needed.
8. Bird and bat collisions, noise, visual impact.
9. Careful siting and better turbine design.
10. Wind speed, access to power lines, public acceptance.
11. Texas, Iowa, Oklahoma.
12. Steel, concrete, fiberglass, carbon fiber.
13. 20-25 years.
14. Made of hard-to-recycle composite materials.
15. Researching recyclable blade materials.

1. Possible Answer: Wind energy produces electricity without emitting greenhouse gases, unlike fossil fuels, which release carbon dioxide and other emissions that impact the environment. Wind turbines also use no water for operation, whereas natural gas, and coal plants often require significant water resources. However, wind energy has trade-offs, such as the impact on birds and bats, noise, and the visual effect on landscapes. Additionally, manufacturing turbines requires materials and energy, and recycling turbine blades remains a challenge. Overall, wind energy has a smaller environmental footprint than fossil fuels, but it is not impact-free.
2. Possible Answer: Many students might argue yes, the benefits outweigh the costs, because offshore wind farms produce more consistent and powerful energy due to steady ocean winds, and they can be placed far from populated areas, reducing land use conflicts. They also contribute to reducing greenhouse gas emissions. On the other hand, the costs are higher due to construction challenges, maintenance difficulties, and environmental impacts on marine life. Whether the benefits outweigh the costs depends on how well these challenges are managed and the value society places on clean, renewable energy.
3. Possible Answer: Communities and companies should prioritize repowering existing turbines by upgrading parts or installing newer, more efficient models. Recyclable materials like steel and copper should be recovered and reused. Efforts should also be made to develop and adopt recyclable blade materials. Disposal methods should follow environmental regulations to avoid landfilling non-recyclable components whenever possible. Planning ahead for decommissioning and including sustainability goals in project planning can help reduce costs and environmental harm over the long term.

Computation

Instructions: Provide students with the Science of Wind – Computation activity for math integration and practice.

Answer Key: Q1: (2304.44 – 345.92) / 13 = 150.66 TWh/year
Q2: 2020-2021 saw the largest increase of 258.79 TWh.
Q3: (2304.44 / 29,429.05) = 0.783 = 7.83% Q4: 2304.44 + (2 x 150.66) = 2605.76 TWh
Q5: (Answers will vary) Example: Falling costs of wind technology, government policies and subsidies, technological advancements, environmental concerns, energy security.

Data Set

Instructions: Instructions: Provide students with the Science of Wind – Data Set for data literacy and analysis practice.

Answer Key: Question 1: In the late afternoon/early evening (5 PM – 7 PM). This could be because people are returning home from work or school and turning on appliances, lights, electronics, etc. It’s also one of the hottest parts of the day, increasing cooling needs.
Question 2: No. Wind output is higher in the early morning hours and lower during the afternoon and evening, which is when electricity demand peaks.
Question 3: (Answers will vary) Example: Turbines can only generate near capacity when wind speeds are optimal; the wind may simply not be strong enough.
Question 4: (Answers will vary) Example: Geography and availability of water resources; cost of installation; fuel access; environmental impact.
Question 5: (Answers will vary) Example: Energy storage systems; complementary energy systems.

Lab Investigation: Wind Energy

Instructions: Use the Lab Investigation: Wind Energy – Student Handout and the following Teacher Guide to conduct the lab activity.

Introduction

In this investigative lab, students will construct a functional anemometer to measure wind speed, and use their data to calculate the wind energy potential of a wind turbine. They will simulate how engineers determine optimal turbine locations by applying scientific and engineering practices.

Investigation Outline

Materials

Student Objectives

Students will be able to

• Construct and calibrate a basic anemometer to accurately measure wind speed.
• Collect wind speed data under various conditions and analyze it using the wind power equation to evaluate energy potential.
• Explore how variations in wind speed and turbine dimensions influence energy output, and apply findings to inform wind turbine placement decisions.

Part 1: Analyzing the Wind Power Formula

• Provide students with the Student Handout. They will use this resource as a guide through the investigation. 
• Begin the class by leading a guided discussion on the different factors that influence the amount of energy produced by wind turbines. Encourage students to think about environmental conditions (such as wind speed and air density), turbine design (like blade length and efficiency), and location (elevation, proximity to obstacles, etc.).
• To introduce students to real-world examples of successful wind energy farms around the world, show students the Switch Chapter 11 Electricity Options: Wind video.
• Introduce students to the Wind Power formula: Power (W) = 0.5 x ρ x A x v³
• Discuss the equation and what each variable means. Students will have the following table on their handout, defining the variables in the wind power equation.

Part 2: Building an Anemometer and Calibration

• If students will be building their own anemometers, provide them with the required materials. They will need to carefully follow the instructions on the student handout.
• Students will follow instructions on the student handout to use the anemometer to collect wind data, calculating revolutions per minute for three different fan settings.
• Students will conduct three trials for each fan setting, and find the average revolutions per minute. If needed, guide your students through this calculation with the following steps.

Wind Speed Calculation Guide
Students will use the average revolutions per minute from their anemometer data.
A. Calculate distance per minute (cm/min) = Revolutions per minute (anemometer data) x distance per revolution
B. Calculate distance in meters per minute (m/s) = (cm/min) x  (1 m/100 cm)
C. Calculate distance in meters per second  (m/s) = (m/min)  x (1 min/60 seconds)

Part 3: Simulated Windmill Calculations

• Now that students have measured various wind speeds, they will put themselves in the role of energy engineers, deciding whether to install a wind turbine at a specific site. 
• First, students will choose one local location (in the same region or state) where they think a wind turbine might ideally be located.
• Following instructions on the student handout, students will calculate the swept area (A) of a 40-meter blade turbine and use an Air Density Calculator to measure the air density (km/m³) of their location, after researching the current month’s average air pressure, temperature, humidity and altitude.
  *Alternatively, groups could be assigned a variety of locations to compare which would be best suited for wind power. 
• Students will use the wind power formula to calculate energy output for different input values. They will then compare the results and answer reflection questions to analyze patterns and draw conclusions.

Answer Key: Sample Data & Calculations 

Part 1: Analyzing the Wind Power Formula Answer Key

Answers A-E: Many factors could be identified including: wind speed, temperature, humidity, air density, turbine height, blade length, turbine location, obstacles near turbines, turbine efficiency, etc. 
F. The symbol ρ represents air density.
G. Factors affecting air density include altitude, atmospheric pressure, temperature, and humidity. 
H. If air density increases, then wind power increases. 
I. Given the equation, there is a direct relationship between wind power and air density. 
J. A stands for the area of the circle that the turbine blades move through. 
K. The formula for this area is A = πr²
L. The variable v in the equation represents the wind velocity and should be measured in units of m/s. 
M. Wind velocity is measured using an anemometer. 

Part 2: Calibration and Wind Speed Calculations Sample Data

A. Low Fan Setting Data Table

B. Medium Fan Setting Data Table

C. High Fan Setting Data Table

D. Measure the diameter of your anemometer’s circular path (cm)
Sample data: 17 cm 
E. The distance per revolution (cm) can be found with the following formula: π x diameter (Note: You may use 3.14 for π)
Sample Calculation: Distance per revolution = π (17 cm) = 53.4 cm/revolution

F. Low Fan Setting Calculations Table (Sample Calculation)

G. Medium Fan Setting Calculations Table (Sample Calculation)

H. High Fan Setting Calculations Table (Sample Calculation)

Part 3: Simulated Windmill Sample Calculations

A. Month: July
B. Average Temperature: 85.5 ^oF 
C. Average Humidity: 69% 
D. Average Air Pressure: 29.54 in of Mercury
E. Altitude: 489 feet above sea level 

F. Wind Turbine Survey Data Table (Sample Data)

G. Wind Power Calculations Table (Sample Calculation)

H. 366 W x (0.4) = 146 W 
I. Answers will vary.
J. Even small changes to wind speed will have a significant effect on the overall power output. This will occur because in the wind power equation, the velocity is cubed, thus having a big impact. 
K. The power output drops to zero. This occurs because the wind turbine must be shut down and rotation stopped to prevent damage to the equipment. 
L. At wind speeds of 40 km/hr, the expected output is roughly 0.7-0.8 MW. The best site would be one that has winds consistently at, or near, the rated speed to ensure maximum performance. 
M. The graph shows an exponential increase up to the rated speed, demonstrating that slower than optimal wind speeds have a much lower output. It also shows that very high wind speeds also result in no power being produced. 
N. Answers will vary but may include: acceptance of local stakeholders (due to sight, noise, etc of turbines), migratory patterns of birds, distance from the grid and other transmission lines, accessibility for maintenance, zoning laws, cost of installation and maintenance, weather extremes in the area, etc. 
O. Answers will vary but students may have inconsistencies in counting the number of revolutions of the rotating anemometer as it can be particularly difficult to count at higher wind speeds. This would certainly affect the accuracy of the results.
Note: To compare, students could apply the wind power equation using some theoretical wind speeds (e.g. 20 – 40 miles/hour or 9-18 m/s) to obtain more accurate values. 

Exit Ticket

Instructions: Access the Exit Ticket and have students reflect on and answer the prompt.