National curriculum, QCA Schemes of Work links
KS3, Sc4, Unit 7I - Energy resources.

Main learning objectives
Pupils learn:
how a device works using a renewable resource;
that renewable energy resources can be used to generate electricity;
to make and explain predictions;
to find patterns in results;
to decide whether evidence supports their predictions.

Wind turbine modelling

Turning renewable kinetic wind energy into electrical energy.

RESOURCES REQUIRED

1. Each working group will need… (See USEFUL WEBSITES for parts supplyers.)
   1 small low voltage “solar motor”
   1 motor “self adhesive motor mount”
   2 “miniature gears”/model makers cogs
   1 Black lead with croc clips
   1 Red lead with croc clips
   2 medium/large plastic bottles, salvaged
   Plastic and cardboard packaging, salvaged
   8 - 10 drink stirrers, salvaged
   Sticky tape
   Access to Cool Melt Glue Gun & recycled medium thickness cardboard
   Access to water (for weighting turbine base)
2. The class will need…
   1 volt meter
   Access to the outdoors on a windy day OR an electric fan
   (An anemometer – optional)
3. Example turbine (built following the instructions below).
4. Projector for, or copies of the "Wind-power CASE STUDIES" in black and white or colour

TIME REQUIRED

Preparation
Up to an hour for gathering resources and constructing example model
Class time
Approximately two periods

TEACHING ACTIVITIES

Introduction - What are fuels? Sharing and categorising experience of fuels.

• “Renewable energy resources include sunlight, wind, waves, running water, biomass and some heat from deep underground (geothermal).”
• “To make use of these energy resources we often need to use science and technology to make things such as hot water and electricity.”
• “As an example of using machines to make use of the energy in wind, we are going to construct wind turbines that turn wind energy into electrical energy. Then we will hold a competition to see which generator produces the most voltage/electricity.”
• Project or hand out copies of the "Wind-power CASE STUDIES" in black and white or colour
  “Wind energy is one of the cheapest of the renewable energy technologies. It is competitive with new clean coal fired power stations and cheaper than new nuclear power. This makes it a great option for poorer countries who are trying to build their power generation capacity. It’s also very relevant for the UK, where we have the largest potential wind energy resource in Europe.”

Constructing wind turbines

• Working in pairs or small groups, pupils will use the resources listed above to construct a wind turbine with the aim of creating a machine which turns as much energy in the wind into electrical energy as possible.
• Explain the following steps:-
1. Build the tower. Half fill one bottle with water and firmly screw cap on. Cut the other in half and stick the bottom half over the top of the water filled bottle to make a flat top.

2. Construct the hub for the blades. Decide how many blades to have. Take that many drinks stirrers and use the glue gun to glue them, sticking out at regular intervals, between the two plastic gear cogs. Make sure that the central holes in the cogs meet up. Consider whether pupils should wear goggles when using glue guns.

3. Make the blades. Cut blade shapes out of cardboard or plastic. Ensure that all the blades for one turbine are identical. Encourage groups to make different shapes from each other for comparison later. Blades can be varied by cutting out particular shapes, by using a curved material (e.g. from a plastic bottle) or by bending or folding the blades along their edges.

4. Assemble the blade-set. Tape a blade to each drinks stirrer, deciding what angle to use (22.5 degrees from facing flat-on is ideal, but pupils do not need to know this).

5. Make the platform. Cut out a flat rectangle of stiff card/plastic to stick to the top of tower and extend out a bit on one side. It needs to stick out just far enough to keep the blades from touching the tower but not so far that the whole thing might wobble over!

6. Put together the whole wind turbine. Tape the platform to the top of the tower. Attach the motor mount to the front edge of the platform. Push the blade-set onto the shaft of the motor. Finally, fit the motor, along with blade-set, into the motor mount.

7. Tip. Only use glue gun to fix the drinks stirrers in between the two gear cogs. Use sticky tape for the rest so that it’s easier to re-use parts.

Competition

• Discuss how the class could devise a fair test for the different generators using the volt meter and an electric fan or the wind outside. Suggest ways of taking wind speed into consideration. For instance, bought or basic class-made anemometers can be employed or distance from the electric fan can be measured.
• Display the finished turbines to the class and write up which turbine each pupil/each group thinks will win, and why. Reasons might include number of blades, shape of blades or size of blades.
• Hold the competition, making use of the ideas everyone came up with for conducting a fair test. Record the results.
• Discuss which variable (number of blades, blade shape etc) the class thinks had the most effect on the results. Each pupil then creates a graph or chart displaying the results in relation to the chosen variable.
• Look back at the pupils’ predictions and discuss their validity in the light of evidence gathered.
  

VARIATIONS

If you wish to measure current, resistors can be incorporated into the models. This might take a little experimenting to see what resistance works well with the motors you have. Try somewhere between 5 to 1000 ohms and arrange a few so that the class can easily try different ones.

SUGGESTED INTERNET/LIBRARY HOMEWORK

1. “Describe how a wind generator works and draw a diagram showing this. For ideas and information visit www.bwea.com/ref/faq.html#makeelectricity and www.bwea.com/energy/how.html and www.cat.org.uk (click on “Windfarm and wind turbine interactive demonstration” in the bottom right corner of the page).”
   OR
2. Hand out the Wind-power WORKSHEET.
   “Research the questions on the worksheet and write a letter to a newspaper outlining the benefits and problems of wind power, saying whether you are in support of wind farms and why.”
   

USEFUL WEBSITES

• Wind power information
  www.bwea.com/index.html The British Wind Energy Association – lots of facts and figures about the British wind industry. Good for finding places of local interest to visit.
  www.scoraigwind.com Website of Hugh Piggott, well known small scale wind expert.
• Parts suppliers
  www.cat.org.uk > “Green Shop” > “Solar Products” > “CAT Solar Kits”
  www.alternativetechnology.org.uk > "Green Shop" (online Catalogue) > "Kits and accessories".
  www.rapidelectronics.co.uk
  Bear in mind that many of the model parts are cheaper from Rapid electronics than specialist green shops.