Kansas KidWind Challenge
Knowledge Quiz Study Guide
9th - 12th Grades Division
Introduction
The Kansas KidWind Knowledge Quiz consists of 10 questions (mostly multiple choice) that are focused on concepts (not memorizing numbers or statistics). Students will be expected to read and analyze data from charts. There are different sets of questions for each age division (4th-5th, 6th-8th and 9th-12th).
This slideshow includes the information and resources used to develop the Kansas KidWind Challenge Knowledge Quiz. If there is a subject you want to cover in more detail with your students, there are optional resources and activities included in the speaker notes.
You can also check out our Activities & Curricula page and Equipment Library page. We have a spreadsheet that details how our activities align with the Next Generation Science Standards.
What Topics Are Covered?
There is a glossary at the end of this study guide that might come in useful!
Just Getting Started?
This free guide, Exploring Wind Energy, from the National Energy Education Development (NEED) is a great resource. Students can read the first ~20 pages to gather information on energy, wind, wind turbines, electricity, and more. The teacher guide provides lessons that help prepare students for the KidWind Challenge. Activities include learning siting a wind farm, designing a generator, and blade aerodynamics!
This guide is to help students learn about wind energy. Knowledge Quiz questions are created based on the next slides in the study guide.
Wind Energy Overview
What is Wind Energy?
Wind is an important renewable resource here on Earth. Wind is caused by the sun heating the surface of the planet. The sun is the original source of energy also known as radiant energy.
Because the surface of the planet is made up of different types of land and water, it absorbs heat from the sun at different rates. As warm air rises, cooler air moves in to take its place. This movement of air from high pressure to low pressure creates wind! Hills, mountains, vegetation, water, and even the Earth’s rotation all have an impact on wind flow patterns, too.
What is wind energy? (cont.)
Air is made up of molecules. Gravity keeps air from escaping Earth. As air starts to warm up it rises and cool air replaces the warm air. The molecules in warm air move faster and farther apart. Molecules in cool air move slower and are packed closer together. Due to more molecules being packed together cool air is more dense than warm air. This also means that cool air has higher air pressure compared to warm air. Temperature and density impact air pressure.
What is air density?
It is hard to imagine that air weighs very much, so let’s talk about water first. If you put one gallon of water on a scale, you will find it weighs about 8.34 pounds. That means the water density is 8.34 pounds per gallon. That’s the mass ÷ volume.
What if you weighed a gallon of feathers? Which would be more dense – the gallon of water or the gallon of feathers? Take a look at the image above. Which material is more dense? Why? The image above could also represent air molecules. Which model best represents the amount and movement of molecules for cooler temperatures?
Although air has very low density compared to something like water, it is important to understand that air density plays a critical role in creating wind!
A
B
Humans Harnessing the Wind
Humans have been using wind energy for thousands of years. Sails allowed us to travel in boats to explore the world (as far back as 5,000 BC). Since as early as 200 BC, windmills helped to pump water or crush grain. Now we often use wind turbines to create electricity from wind. Wind is harvested through wind turbines, when the generator converts mechanical energy into electrical energy.
Wind Turbines
Windmill vs. Wind Turbine
You’ll often hear people say “windmill” when perhaps they mean “wind turbine.” While both devices harness wind energy and put it to practical use, they have quite different roles.
Windmills are machines with mechanics that are powered by the wind (such as milling grain or pumping water). Wind turbines convert wind energy into electrical energy.
Windmill used to pump water in Morris County, KS by KEP
Types of Wind Turbines
There are many variations of wind turbines, but they mostly all fall into two types: horizontal-axis wind turbines (HAWT) and vertical-axis wind turbines (VAWT). Almost all the wind turbines you see on the Kansas landscape are horizontal-axis. They look like an airplane propeller and their shaft is horizontal. Vertical-axis wind turbines (VAWTs) have blades that connect at the top and the bottom of a vertical rotor. These machines look more like an egg beater or whisk.
Types of Wind Turbines (continued)
Horizontal-axis wind turbines (HAWTs) are more often utilized in large wind farms. In general, more electricity can be produced from a given amount of wind using a HAWT.
VAWTs are more likely to be used in residential applications or smaller wind farms, as they perform well in tumultuous conditions and are ideal for sites without consistent wind patterns, or where turbines cannot be placed high enough for steady winds.
Wind Turbine Measuring Devices
(1) Anemometer: measures wind speed.
(2) Wind Vane: measures direction of wind and helps turbine yaw (you will not need to worry about this for the KidWind Challenge unless you make it to Nationals).
(3) Energy Sensor: Used to measure energy output, voltage, current, and resistance.
(4) Wind Tunnel: used as the source of wind to test energy output of wind turbines.
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How do you think these devices are used in the real world?
Parts of a Wind Turbine
Blade Pitch: angle of blades due to the plane of rotation.
Gear Box: connects the low-speed shaft to the high-speed shaft and increases the rotational speeds.
Generator: houses the metal coil that spins within a magnetic field and converts mechanical energy into electrical energy.
Controller: the nervous system of the turbine; at higher speeds it will turn off the turbine to avoid damage.
Anemometer: measures wind speed.
Nacelle: houses the generating components.
Yaw Drive and Motor: keeps the rotor facing into the wind as the wind direction changes.
Tower: supports structure of turbine.
Blades: causes the rotor to turn.
Rotor: rotating section comprised of blades projecting from a hub.
How does a generator work?
This video does a nice job of explaining how a generator works. Basically, a generator produces (or generates) electricity by moving a magnet near a wire to create a flow of electrons. In the case of our wind turbines, if you open up the generator, you will see that we’re using energy from the wind to make our coil of wires spin inside a magnetic field!
Check out the inside of a KidWind generator on the left!
Wind Siting
When choosing where to construct a wind farm, there are many things to take into consideration. Engineers like locations -
Calculating Wind Power
Calculating Wind Power
Use the wind power formula on the previous slide to evaluate a wind turbine that has blades that are 50 centimeters or 0.5 meters long.
Example Formula:
½ × 1 kg/m3 × ??? square meters × (3 m/s)3 = ??? Watts
The Betz limit is a theoretical maximum efficiency for a wind turbine. At most, only 59.3% of the kinetic energy from wind can be used to spin the turbine and generate electricity. We will discuss more in later slides.
Dependent and Independent Variables of Wind Turbines
Examples: Blade length, pitch, & wind speed.
What other variables can you identify?
What are the differences between the control, dependent, and independent variables?
Why might you only want to change one variable at a time?
Circuits
Please check back. This section will continue to be updated.
Electrical Circuits
Breadboard Circuit
A breadboard circuit is used for building temporary circuits without needing to solder. They are useful for designers because it allows components to be removed and replaced easily.
Use a Multimeter to Measure Voltage
Gears
What Do Gears Do?
Most gears are circular objects or wheels with “teeth” that engage another device (typically another gear) in order to change the speed or direction.
Can you brainstorm where you’ve seen gears in the real world?
Why do we use gears in our wind turbines?
Wind Turbine Gears
Gear Ratio
What did you notice on the last slide? The 32-tooth gear rotating one time caused the 8-tooth gear to rotate four times! What is 32 ÷ 8?
That’s not just a coincidence, that’s the gear ratio! You can use the number of teeth to determine the number of rotations. Take a look at this formula:
In this formula, the “driver gear” is the gear that’s connected to the turbine shaft. It’s the gear that’s in control and doing the “driving.” The gear that’s being turned by the driver gear is called the “driven gear,” because it’s being driven by the first gear!
Gear Ratio Example
What are the gear ratios of the two sets of gears?
Which gear set will produce the most electricity when used in the wind turbine?
Compound Gears
Compound Gear Train Example
Compound Gears
Introduction to Energy
Renewable and Non-Renewable Resources
Renewable Energy:
These energy sources can be replenished quickly.
Examples include: Biomass, hydropower, wind, solar, and geothermal
Non-Renewable Energy:
These energy sources are limited and take a long time to form.
Examples include: Petroleum, natural gas, coal, uranium (nuclear), and propane
Discuss advantages and disadvantages of renewable and non-renewable energy.
Primary Energy Resources
Primary energy sources include fossil fuels (petroleum, natural gas, and coal), nuclear energy, and renewable sources of energy. Electricity is a secondary energy source that is generated (produced) from primary energy sources.*
Oil and Petroleum: mixtures of hydrocarbons that formed from remains of animals and plants
Natural Gas: an example is methane (CH4); a byproduct is propane (hydrocarbon gas liquid)
Coal: combustible sedimentary rock
Nuclear (Uranium): energy in the core of an atom
Solar: the sun is the ultimate source for all of the energy sources and fuels that we use
Hydro: relies on the water cycle
Wind: caused by uneven heating of the earth’s surface by the sun
Geothermal: heat within the earth
Biomass: organic material from plants and animals
Energy Types and Forms
Types:
Potential: stored energy and the energy of position.
Kinetic: energy in motion of waves, electrons, atoms, molecules, substances, and objects.
Forms:
Radiant: light and sunshine are examples
Mechanical: all living things and machines use this to do work. It is all the energy that an object has because of its motion and its position. An example is a pendulum: the kinetic energy of the balls in motion plus the potential energy of the balls that are still.
Electrical: delivered by electrons moving through a wire - lightning is an example in nature (without the wire, of course)
Thermal: energy from movement of atoms and molecules in a substance - heat
Sound: movement through waves
Chemical: stored in bonds of atoms and molecules - biomass, coal are examples
Nuclear: energy stored in nucleus of atom
Gravitational: energy stored at an object’s height - hydropower is an example
Transformations
A wind turbine transforms mechanical energy into electrical energy.
But how? As the kinetic energy of the moving wind is converted to mechanical energy, it rotates the blades of the wind turbine that then rotate a generator shaft located inside the nacelle. Rotating the generator shaft causes a coiled wire to rotate inside a magnet and creates an electrical current. Since energy is neither created nor destroyed, the greater the energy input, the greater the energy output will be. Therefore, the more mechanical energy you start with -- the faster the blades turn -- the more electrical energy will be created by the turbine.�
What other examples of energy transformations can you come up with?
Science Laws and Principles
Law of Conservation of Energy: Energy is neither created nor destroyed - only converted from one form of energy to another.
Examples:
Betz Limit
Power Grid:
Wind to Electricity
DIscussion:
The U.S. electrical grid is divided up and managed by different groups called "Regional Transmission Organizations" or RTOs. Which RTO does Kansas belong to? Can you research what an RTO does?
Explore the website to see the price contour map, generation mix, and the forecast vs actual data.
Power Grid:
Losses
Discussion:
How does the energy go from wind to electricity?
Where do we lose energy?
How much energy do you think we lose in the process?
Wind Energy Data
The KidWind Knowledge Quiz questions will focus on understanding concepts rather than memorizing statistics or numbers. The information in this section is primarily included because students may find it interesting. Students will be expected to read and analyze data from charts, not memorize values.
Wind Energy Data - Kansas
Kansas has an immense wind resource, which makes it a national leader in total wind power capacity and percentage of electricity generated by wind.
Look up information about the wind farm nearest you with the US Wind Turbine Database.
2021 Wind Energy Data - United States
The United States is a global leader in the Wind Industry with the second most total wind power capacity. However, wind only accounts for about 9% of the total electricity generated in 2021.
GUESS THE NUMBER FOR THE U.S.
What percent of energy consumed in the U.S. was “lost” in the year 2021?
Which energy source do you think we consumed the most?
1 Quad = 1 quadrillion BTUs (1015) = 1.055 x 1018 Joules
https://flowcharts.llnl.gov/sites/flowcharts/files/2022-04/Energy_2021_United-States_0.png
GUESS THE NUMBER FOR KANSAS
What percent of energy consumed in the Kansas is “lost” in the year 2019?
Which energy source do you think we consume the most?
Wildlife Impact
Environmental Impact
Discussion:
Consider the impacts of electricity generation on wildlife.
Are birds impacted by turbines? Are bats impacted by turbines? If so, to what degree?
Explore and describe the relationship between technology and nature.
Virtual Review Games
Review Games
Kahoot: KidWind KEP Knowledge Quiz Review
Blooket: KidWind Knowledge Quiz Review
Gimkit: KidWind Knowledge Quiz Review
Quizlet: KidWind Knowledge Quiz Review 2023
Glossary
GLOSSARY
reversed by alternating the magnetic poles past the coils. Most household
outlets have AC current.
GLOSSARY
the magnets past the wires or vice versa. The more wire that interacts with the magnetic flux, the higher the voltage and subsequent current generated.
GLOSSARY
or weaker depending on the type of magnet. Different areas of the magnet have opposite or opposing forces. We typically label these areas the north and
south poles.