Competition Elements

Worlds Pages

Competition Elements

Every wind and solar team competing in the World KidWind Challenge will participate in several competition elements, including either wind turbine or solar home testing, a presentation for a panel of judges, two Instant Challenges, and the Quizbowl.

The judging, Instant Challenge, and Quizbowl components of Worlds will be scheduled for each team. Wind turbine and solar structure testing will be self directed in between the other Competition Elements during Worlds.

Bonus Points! There are 3 bonus points available that teams can earn BEFORE coming to Worlds. These must be completed by May 2nd in order to receive the extra points.

Complete your Team Profile with a working video (1 point)
Submit ALL Attendee Forms for people joining your team for Worlds (students, coaches, and chaperones) with Liability & Media Release Forms (2 points).

Learn what to expect and important rules for each element by clicking on the buttons below.

Competition Elements with a * next to them will be scheduled at a specific time for each team.

Wind and Solar teams will be scheduled for a judging session to present their structure to a panel of judges, discuss their project, and answer questions.

We will have more than one judging room going at a time, so multiple teams will be scheduled for the same session.

We encourage all teams to prepare a formal presentation and share supplementary materials which may include photos, data tables, notebooks, and/or project iterations. For teams that prepare a digital presentation like a PowerPoint, we will have a small screen similar in size to a desktop monitor, and a variety of dongle options to connect your device in order to present.

What to bring to your judging session:

Your physical turbine or solar home. Plan accordingly to move your device from the staging area to the judging rooms. Wind teams - Be sure to save any turbine-busting tunnel time until after your judging session.
Wind Teams Only: Executive Summary, required for Middle School & High School teams, recommended for Elementary School teams.
- MS/HS Instructions
- ES Template
Solar Teams Only: Documentation outlined below and on Rules page
A formal presentation prepared for the judges. This may include a poster board, physical items for the judges to view like design iterations and data logs, or digital slides that detail your process.
Any setup and takedown required of your device should be thought out ahead of time to minimize eating into your timeframe with the judges.

Each wind team will be scheduled for a 15-minute wind turbine judging session with a panel of judges. During this session, the team will have up to 10 minutes to present their turbine design to the judges. The judges will have the remaining time to discuss the project, ask questions, and evaluate the students' knowledge.

Why is the presentation important?

The purpose of the presentation is to provide the judges a better understanding of the process the students went through as they designed and tested their turbine. Teams should be prepared to discuss and defend the choices incorporated into their design. This is also the team’s opportunity to share their documentation of resources and past design iterations, as well as their understanding of wind and energy in general. Judges may identify qualities during this time that can elevate the consideration of a team in the running for a recognition award outside of scoring criteria.

What are the judges evaluating during the presentation?

Judges will ask questions to better their understanding based on what is presented using a wide range of criteria as a guideline when evaluating teams on their presentation and turbine design:

Blades
Drivetrain
Generator
Innovation (Inspiration and Creativity)
Independence
Overall Appearance and Material Selection (Aesthetics)
Documentation
Depth, Complexity, and Clarity (Understanding)
Delivery and Preparedness

Each solar team will be scheduled for a 30-minute solar home judging session with a panel of judges. During this session, the team will have up to 10 minutes to present their design to the judges. The judges will have up to 10 minutes to assess the performance of the solar home under a solar array. The judges will have the remaining time to discuss the project, ask questions, and evaluate the students' knowledge.

Why is the presentation important?

The purpose of the presentation is to provide the judges a better understanding of the process the students went through as they designed and tested their solar home. Teams should be prepared to discuss and defend the choices incorporated into their design. This is also the team’s opportunity to share their documentation of resources and past design iterations, as well as their understanding of solar and energy in general. Judges may identify qualities during this time that can elevate the consideration of a team in the running for a recognition award outside of scoring criteria.

What are the judges evaluating during the presentation?

Judges will ask questions to better their understanding based on what is presented using a wide range of criteria as a guideline when evaluating teams on their presentation and solar home design:

Theme and Purpose
Design and Functionality

Solar Arrays and Circuits
Loads and Switches
Power Storage (if applicable)
Microcontroller (if applicable)

Required Documents

Solar Panel Schematics
Wiring Diagram
Report
Materials List
Programming Code (if applicable)

Inspiration and Creativity (Innovation)
Independence
Aesthetics and Material Selection (Overall Appearance)
Documentation
Depth, Complexity, and Clarity (Understanding)
Delivery and Preparedness

Standard Wind Tunnel Testing Protocol

Each team competing in the Wind Challenge will need to run their wind turbine through multiple distinct tunnels at the World KidWind Challenge, each with their own unique focus. All tunnels draw wind through the tunnel creating a much cleaner and more stable airflow. The size of the wind tunnel testing space is 48” x 48” x 48”. Keep in mind, though, that the walls move in a bit when the tunnel is running so teams should account for at least a 4” buffer of safe space between blades and tunnel sides to account for shrinkage. Hitting/damaging the tunnel’s vinyl shroud, may result in “0”.

Each team must find time to test their wind turbines in the wind tunnels during Worlds when they are not participating in the other scheduled Competition Elements.

Tunnel Specifics

We will have 5 wind tunnel types, with 2 tunnels of each type (apart from the Shark Super Tunnel). All grade division teams test under the same wind conditions, including Yaw Test.

TUNNEL TYPES - Each tunnel is worth 10 Points

Low Speed: ES/MS Tunnel 1 & HS Tunnel 2 (2-4 m/s)
Medium Speed w/ Efficiency Test: ES/HS Tunnel 1 & MS Tunnel 2 (3.5-5 m/s)
Medium Speed & Yaw Test: ES/HS Tunnel 1 & MS Tunnel 2 (3.5-5 m/s)
High Speed: ES Tunnel 1 & MS Tunnel 2 (At least 5.5 m/s)
Shark Super Tunnel: HS Only Tunnel 1

Please note: These are just estimates. Onsite variables may result in a different wind speed. Measured speeds will be posted at each tunnel. We will work to provide speeds that we have advertised to teams.

There will be a timer at each tunnel, each team will need to be out of the tunnel in 5 minutes from set up to testing.

SPECIAL NOTE: CHANGING BLADES & GEARBOXES BETWEEN TUNNELS - UPDATE!

After a careful review of our procedures we have decided that teams will be allowed to change blades (number, material, pitch, etc) and gearboxes if they would like between wind tunnel tests.

SPECIAL NOTE: CATASTROPHIC FAILURE DEFINITION - UPDATE!

An event that causes a turbine in the wind tunnel to produce zero power while collecting test data is defined as a Catastrophic Failure Event. This could be due to either a mechanical or electrical failure.

If this happens, you will be offered the following options:

Receive two minutes to set up your wind turbine again
Remove the turbine to make repairs. In this case, you will be moved to the back of the line for retesting.

Failures that lead to REDUCED performance are NOT considered catastrophic, and a retest would not be allowed under these circumstances.

Catastrophic failures that are INDUCED by a mechanism will not be treated as a catastrophic failure and NO RETEST will be awarded. (meaning tripping something to cause a failure - ex knocking a blade or gear off )

During tunnel testing, teams must run their turbines through each tunnel. Each team will receive a set number of tokens at check-in that they must trade-in to test their turbine in the wind tunnel.

Each tunnel will use a different color token and one tunnel run requires one token. You can assume that you will receive 2-3 tokens per tunnel, meaning 2-3 active runs per tunnel. Once the number of teams attending Worlds has been confirmed, we will finalize the number of tokens to be distributed.

Each tunnel will have a visible timer. Each team will have just 4 minutes to get their turbine set-up in the tunnel and complete their test. Tunnel judges can add additional time to the timer at their discretion.

TOKEN: Hand 1 tunnel token to the tunnel judge. Be sure the color of the token corresponds to the color of the tunnel.
TURBINE SET-UP: Place your turbine in the tunnel and connect the wires to the data logging hardware.
FANS START: The tunnel judge will turn on the fan and let the tunnel and turbine get up to speed. This will take about 30 seconds.
GO/NO GO CALL: At the 30 second mark, the tunnel judge will ask if you want to run a trial. You can say YES or NO.
DATA COLLECTION:
- If you say NO (you do not want to run a trial): Remove the turbine, collect back your token, make any adjustments and go to the back of the line.
- If you say YES: The 30 second trial begins. The only way that a test can be redone is if judges determine that there has been a Catastrophic Failure because your turbine has failed and/or your output has dropped to ZERO.

PROTOCOL & SCORING (All Levels)

Why do we measure efficiency? Our goal is to see how well your wind turbine (blades, generator, gearbox etc) converts the power in the wind to electrical power. The theoretical maximum for efficiency is 59%, this is called the Betz Limit.

Read more about the Betz Limit here and a little deeper here.

To calculate your turbine efficiency we need a few numbers.

The swept area of your turbine blades - how to calculate swept area.
The max power produced by your turbine in a 30 second test
The wind speed in the tunnel

Using these numbers we calculate the power AVAILABLE for your size rotor. We compare that to the power your turbine ACTUALLY generates and we calculate efficiency.

Common efficiency numbers for KidWind Turbines range from 3-10%.

The larger you make your rotor diameter, the harder it is to get a high efficiency score, because your AVAILABLE power keeps increasing! In a 1 meter circle of wind moving at 3.0 m/s there is 12+ watts of power. It is hard for a KW turbine to generate that much so you get a low efficiency score.

We will be using the Standard Wind Tunnel Test Protocol.

Before the turbine is tested in the tunnel a judge will record the largest measurement, in meters, from the center to the outermost tip. This is not always directly along the blade, depending on the blade shape.

Scoring is Ratio Based - Highest Efficiency in each category/level gets 10 points rest are a ratio to this.

PROTOCOL & SCORING (All Levels)

Why do we test if your turbine can yaw? It is important for a wind turbine to track the wind. Large wind turbines use fancy hydrological and anemometers to track into the wind, smaller turbines use vanes and other techniques to accurately track the wind. Your team needs to figure out how to do this to score the maximum points on this test.

What is Yawing? Learn more - https://en.wikipedia.org/wiki/Yaw_system

In the yawing tunnel, you will place your turbine on a base plate. We will spin up the tunnel and begin collecting data. After about 10 seconds, we will push a button that activates a motor that will rotate this base plate 90 degrees.

We will be recording your power and energy for the whole test.

You will get 2-3 tests in this tunnel.

Important Things to Keep in Mind:

The base plate that holds your turbine will be 41” in diameter and has a max weight of 70lbs (including any weights your turbine may need).

Keep in mind that your turbine will be turning - you don’t want the blades to hit the sides of the tunnel. If your blades do hit the vinyl shroud of the tunnel, you may receive a penalty and a reduced performance score in the tunnel and you will not receive a re-test.

We will have a place where you can test the rotation of your turbine to see if it will hit the tunnel sides.

We discourage the use of “lazy susans” to make your turbine yaw! Think about some other techniques to track the wind!

Scoring is Ratio Based - Highest Energy Score in each category/level gets 10 points rest are a ratio to this.

If your turbine FAILS to yaw your performance will probably be reduced and we will dock your team 2 points as this is the point of this test. Proper yaw alignment results in the rotor facing directly into the source of wind. Turbines that FAIL are more than 30 degrees off proper alignment.

PROTOCOL & SCORING (HS Only)

The challenge is to pump the highest column of water in the shortest time using wind power and a simple DC water pump.

A member from your team will control the starting of the wind tunnel, the speed of the wind tunnel and the stopping of the test. It will not be controlled by KidWind judges.

Time begins when the wind tunnel is started and continues until the designated team member tells the judge to STOP THE TEST/TIMER. The height of the water column reached will be measured in CM and this number squared and then divided by the time in seconds it took to get to this height.

Teams must NOT exceed the 300 cm height limit. Teams exceeding the 300 cm height limit will score a zero for that test run. The maximum test time will be limited to 60 seconds.

Teams in the KidWind Generator Division will be pumping water with a pump limited to 12 volts with a buck converter.

Teams in the Open / Homebuilt Division will be pumping water with a pump limited to 24 volts with a buck converter and have a 30 ohm resistor in the circuit.

This number will be the teams score:

Score = Water Column Height ^2

—------------------------------

Time in seconds

SCORE EXAMPLES

Example : #1 100 cm water column height in 30 seconds 100cm ^2 = 10,000 / 30 sec = 333

Example #2 50 cm water height in 10 seconds 50cm ^2 = 2,500 / 10 sec = 250

Example #3 2 50 cm water height in 55 seconds 250cm ^2 = 62,500 / 55 sec = 1136

Example #4 250 cm water height in 45 seconds 250cm ^2 = 62,500 / 45 sec = 1388

So...

Team # 4 got 1st place with 1388 scores 10 points

Team #3 got 2nd place with 1136 is 81.1% and scores 8.1 points

Team #1 got 3rd place with 333 is 23.9 % and scores 2.3 points

Team #2 got 4th place with 250 is 18% and scores 1.8 points

MORE TESTING DETAILS

The water pumps are non-positive impeller types. As the weight of the water in the column increases it will require more power from the generator (volts X amps) . At a point when there is not enough power from the generator to keep raising the fluid head of pressure the water will no longer rise and the impeller in the pump will just spin.

As the speed of the wind increases in the wind tunnel there is more power to be converted, however there are also more forces on the turbine blades and gear boxes that can cause failures. So the team has to decide how much wind speed to apply and how fast to apply it. Get everything right and your turbine survives and pumps the highest column of water in the least time.

During the solar judging session, we will test each solar home in a solar testing rig., which is a bank of lights approximately 1 meter square positioned 1 meter off the table.

Students will place their solar home under the solar testing rig to an optimal position. Students will be able to turn on any switches, microcontrollers, or other controls that are part of their solar project during the judging session to demonstrate performance.

Your solar home will be tested during your 30-minute judging session. Teams can expect to be evaluated on the following criteria: circuit design, functionality, inspiration, creativity, aesthetics, materials, and knowledge about solar power.

Solar Testing Array Specifics

For Worlds, the Solar Blast is the testing array that will be used. This is a static bank of lights that will result in 300-400 W/m2 as the energy source for solar panels - for reference the light output by the Sun is equivalent to 1000 W/m2. Solar devices will need to fit within a 2’ wide by 2’ long by 1’ high space. There will be a 4” buffer of safe space between the maximum height of the solar device and the hot halogen lights.

The Solar Theme for this year is Solar Homes for the Elementary and Middle School Divisions, and Solar Smart Homes for the High School Division.

Teams will need to plan ahead for their judging session to ensure the proper balance. of time to allow for setup, demonstration, presentation, judges questions and removal of themselves with their device.

Solar Testing Protocol

During solar testing, teams must demonstrate the functionality of each circuit and capability of their solar device.

SOLAR DEVICE SET-UP: Place your device in the testing array and make any adjustments that need to be made. NOTE: Judges may ask the team to give their presentation before starting the demonstration.
SOLAR ARRAY START: A solar judge will turn on the lights and let the team activate the device.
DEMONSTRATION: Teams will complete the demonstration portion of their scheduled time with the judges, and indicate when the testing array may be shut off. The judges will ask questions during and after the demonstration.

SOLAR DEVICE REMOVAL: After the demonstration and presentation have been completed, the team will be excused by one of the judges and expected to quickly disassemble their device as needed to return to the staging area and clear the room to allow judges to prepare for the next team.

Solar Teams have a whole list of required times that they must bring with them to their scheduled judging section. Use these handy checklists to be sure you have everything you need!

Instant Challenges are an on-the-spot test of knowledge, skills, problem-solving, and teamwork. These Challenges will be included on each teams' individual Worlds schedule on Monday or Tuesday. They will not require any preparation prior to arriving at Worlds and all materials needed to complete each Challenge will be provided. All team members must participate in each Instant Challenge, and the results will be a part of each team's overall score at Worlds. Each grade division has their own set of Instant Challenges.

This year all age divisions (Elementary, Middle School, and High School) will have 2 Instant Challenges! High School teams will be scheduled for 45 minutes for each Challenge. Elementary and Middle School teams will be scheduled for 30 minute sessions.

Teams will be scheduled to participate in a Quizbowl to evaluate their general understanding of clean energy. The 2025 Quizbowl will be a pen and paper format and teams will complete the quiz together at the same time as the other teams in their age division during a 1-hour scheduled session on Monday. This element will likely have questions projected on a screen and read aloud.

To prepare, teams can consult our 10 Big Questions About Energy resource to frame their learning.