RULES
The rules at the World KidWind Challenge may be different from the rules at your regional events and/or expand upon KidWind's Rulebooks. We encourage you to read the below rules carefully so that you aren't surprised!
Generator Divisions:
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KidWind Division: SINGLE standard KidWind Generator (Teams in the 4-5th grade division must participate in this division).
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Open Division: Any non-KidWind, commercially produced generator, high torque KidWind generator, multiple KidWind generators, OR turbine using harvested parts (coils, rotors) from other generators.
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Homebuilt Division: ALL of the major components of the generator are constructed by the students. This would mean the coils are wound by the students and other components like the stators have been constructed, 3D printed, or otherwise built by the team.
You must declare your generator division when you submit your Team Profile form.
Your turbine will be inspected at the start of the event, locking-in your division. Turbines will be marked with colored stickers at this inspection to indicate the generator division.
No shrouds will be allowed on turbines at the World KidWind Challenge.
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.
UPDATE: Catastrophic failures that are INDUCED by a mechanism will not be treated as a catastrophic failure and NO RETEST will be awarded. This means tripping something to cause a failure, like knocking a blade or gear off, does not qualify as a catastrophic failure.
Teams are allowed to have multiple generators and rotors in one turbine placed in the tunnel. All of these rotors must still fit into the standard wind tunnel.
Keep in mind that if you have multiple KidWind generators, you will be placed in the Open Division.
You must make sure that whatever generator and configuration you use provides DC power to our data loggers below 30V and 1A. If you go over for even 1 second, it can disrupt the software and we will be unable to get a reading.
LOADS
- KIDWIND Division: Teams must use the provided 30 ohm loads.
- OPEN Division: Teams can use the provided 30 ohm loads or any loads they wish.
- HOMEBUILT Division: Teams can use the provided 30 ohm loads or any loads they wish.
In the low, medium, and high speed tunnels, teams cannot change the load during the test. In the super tunnel, teams can actively adjust loads during the test.
POWER CONDITIONING
Maximum Power Point tracking, buck boost, and other similar devices are allowed as a part of power conditioning. Send any technical questions to Mike at Michael@KidWind.org.
BLADE CHANGES DURING TESTING
The spirit of the Wind Challenge at Worlds is to construct ONE wind turbine that can handle different wind conditions. We also understand that teams may have never tested in high speed tunnels and have blades that fail during testing, or just want to test different types of blades in the tunnel.
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.
BLADE CONSTRUCTION
Teams must construct/make all of their wind turbine blades themselves. A team can use blades constructed in a previous year if the majority of the team consists of the students who constructed the blades.
Other components (towers, gearboxes, generators, etc.) not constructed by the team can be used as long as the team discloses these components during their Judging Session. This includes parts that have been made by previous students or purchased.
Keep in mind that at Worlds we are in a space that we do not have full control over, making it impossible to provide the exact conditions needed to guarantee the wind tunnel speeds. As such, the actual measured speed of each wind tunnel may vary at the event from the anticipated speeds shared prior to arriving at the event. Part of this type of competition is adjusting along the way, and remember teams are competing against each other under the same conditions.
SOLAR HOME DIVISION (4-5TH, 6-8TH, & 9-12th GRADE): Solar panels must power all of the solar home’s loads. The loads can also be powered by using a supercapacitor as power storage, charged by the solar panels.
SOLAR SMART HOME DIVISION (6-8th & 9-12TH GRADE): Solar panels must power the majority of the solar smart home’s circuits. If you add a solar powered charge controller to power your microcontroller, it must be connected to the microcontroller. Rechargeable batteries cannot be charged separately then inserted into the microcontroller battery pack.
See allowable & non-allowable storage examples in the 2025-26 Solar Guidebook.
The Solar Home and all accessories must fit within a 2’ width, 2’ length, 1' height space. This provides 4” of safe space between the max height of the solar home and the hot halogen lights.
Teams can use solar panels from any company and any number of solar panels, as long as the individual panels do not exceed 6V or 1.1A, and the total of all the solar panel configurations do not exceed the maximum voltage 24V, current 2.2A or wattage 48W.
→ Each team is required to submit a materials list printed out. Find a materials list template here. You may use the template or make your own.
→ The material list is a document for teams to record all materials used in the solar home, the purpose of the material, if the materials are recycled, found, or new, and the costs of materials.
→ If the material is a 3D printed part, teams must explain if the file was found, modified, or created. Budget should identify 3D printed parts as new material cost. Material cost = filament price/filament weight x model weight.
See allowable & non-allowable materials lists in the 2025-26 Solar Guidebook.
→ Each circuit must have an “emergency” on/off switch that disconnects the power source from the rest of the circuit. These emergency switches must be clearly labeled and accessible.
→ Teams can use any load to make their solar home interesting. These can include LEDs, incandescent bulbs, motors, doorbells, repurposed switches, relays, etc.
→ Pre-manufactured circuits or circuitry kits are not allowed (little bits, snap circuits, etc). Contact us with questions.
→ Power storage can be in the form of capacitors (1 Farad/2.7V), gravity batteries, rechargeable batteries, spring tension or elastic. No Lithium batteries (NiCad, etc) of any kind are permitted.
→ Rechargeable batteries must be powered by the solar panels, directly or indirectly.
→ Pre-manufactured solar battery chargers are not allowed.
→ A solar home is not considered solar powered if teams must manually take charged batteries out of a solar battery charger for placement into a solar home in order to power the loads.
→ Teams must label how the solar panels are charging the power storage and how the storage is powering the loads on the device in the wiring diagram.
→ Loads can be powered using a supercapacitor (supercap) as power storage, as long as the supercap is charged by the solar panels. If a supercapacitor is used, it must be rated at or below a capacitance of 1 Farad and 2.7V. Multiple supercaps can be used, but the max voltage in series cannot exceed 6V. Do not exceed the voltage of the supercap when matching with the voltage output of the solar panel(s). A diode needs to be placed in series with the positive lead of the panel and the positive lead of the supercap.
→ A microcontroller of any make can be used as a charge controller, as long as power storage requirements are followed. A microcontroller can use a battery pack (must be sealed lead acid batteries), but the batteries from the microcontroller cannot power more than 1/3rd (33%) of the loads. If you add a solar powered charge controller to power your microcontroller, it must be connected to the microcontroller. Rechargeable batteries cannot be charged separately, then inserted into the microcontroller battery pack.
→ The Solar Smart Home Division requires a microcontroller, and any team using a microcontroller will be placed in the Solar Smart Home Division. The suggested grade range is 9th-12th, but ambitious younger teams can give it a try! 6th-8th grade teams entering a Solar Smart Home will be judged in a separate Middle School Solar Smart Home division.
→ Any microcontroller can be used.
→ There are no limits to how many microcontrollers can be used, as long as the requirements are followed.
→ The wiring diagram must label all functions of the microcontroller.
→ Teams must provide a print out of the programming code used, and labeled by microcontroller if multiple are used.
→ A microcontroller can be powered by solar panels or use power storage.
All teams must provide Solar Panel Schematics: In the solar panel schematic, include each solar powered circuit’s configuration (parallel/series), and a label to what the terminals connect to. Label each panel’s rated voltage and current, and each configuration's voltage/current total.
See Solar Schematics Examples here: Solar Panel Schematic Example 1, Solar Panel Schematic Example 2, Solar Panel Schematic Example 3.
→ Teams must provide a wiring diagram for each circuit in their project.
→ All age divisions have the option of using our Wiring Diagram Template.
→ Each wiring diagram must include a symbol key.
→ The wiring diagram must use the symbols for all the electrical parts of a circuit, and all parts clearly labeled.
→ Every emergency switch must be clearly labeled in the diagram.
→ If using power storage, teams must label how the solar panels are charging the power storage and how the storage is powering the loads on the device.
→ For the Solar Smart Homes, the wiring diagram must label all functions of the microcontroller.
See wiring examples here: Wiring Diagram 1, Wiring Diagram 2.
Teams must provide a written report, assembled in the order listed below, and organized in a binder or stapled together.
Report includes:
- Division (selection box)
- Grade(s)
- Team name
- Number of team members not including the coach (selection box 2-4)
- Coach name and contact email
- School name and location
- Cover image of solar home
- Size of solar home Solar home title
- Solar Home Summary
- Solar Home Narrative
- Teamwork
While it is not mentioned in the rules, do not forget to include your resources/references.
If teams have an engineering design book or similar, they are encouraged to bring it with to Worlds as they may want to refer to something recorded in it while troubleshooting or speaking with the judges.
Find specific Solar Report requirements in the 2024-25 Solar Guidebook.
The Solar Blast testing array will have light resulting in 300-400 W/m2, for reference the light output of the Sun is equivalent to 1000 W/m2.
These lights get very hot, and while the testing time is short, teams should consider how heat at close range can affect the different materials in their build.
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