Breezy Power: From Wind to Energy: Sixth-Grade Students Work for a Fictitious Power Company as They Explore Electricity and Build Working Wind Turbines
Claymier, Bob, Science and Children
As a former technology education coordinator in my district, my task was to help K-8 teachers integrate our state's academic content standards for technology into their regular curriculum. When two of our sixth-grade teachers asked me to help them develop and teach a lesson on alternative energy, I thought it would be a great time to combine the science concepts of renewable energy and producing electricity with the technology concepts of design, constraints, and technology's impact on the environment.
Over five class periods (an hour each), students researched wind as an alternative energy source and designed and tested a working model of a wind turbine, learning about energy and technology in the process.
To begin the lesson, students were shown pictures of a sailboat, a kite, and a lightbulb and asked to identify similarities (they all can use wind to make them work). Through prior reading, the students knew that wind energy could be transferred to electric energy, but none really understood how wind turbines actually produced electricity. I wrote "How does wind energy produce electricity?" on the board and said it was our main question of the day.
The students were then informed that they were going to be hired (in teams of four) by the Breezy Power Company. This company is thinking about creating a wind farm somewhere in the United States and selling the electricity. The company wants to hire teams of experts (the sixth graders) to research wind energy production in the United States and answer future stockholders' questions, such as: How does a wind turbine produce electricity? Where would be the best place in the United States to build a wind farm? The teams were then asked to design and test a wind turbine model that would actually produce an electric current. There were to be bonus points for the team whose model produced the most electricity.
In previous grades, students had learned about energy as the ability to do work and electricity as the movement of electrons. Students had explored magnets and lines of force in an earlier grade as well. The next day, we reviewed these concepts, and students investigated the relationship between magnetism and electricity to better understand how a wind turbine works.
Students were put in groups of four and given the following materials to work with:
* 1 compass
* 1 iron nail
* 2 bar magnets
* a bell wire, about 50 inches long with ends stripped
* 1 D battery
* a toy electric motor
* iron filings in a sealed petri dish or sealed plastic bag
In addition, the teacher had a multimeter (a device that measures electric current, available in hardware stores for about $20; digital seems to give the most accurate readings) and wire cutters.
The students first put a single bar magnet flat on the desk and placed a sealed clear plastic petri dish with iron filings inside on top of the bar magnet to show magnetic lines of force around a magnet. A discussion determined that the iron filings lined up according to the magnet's lines of force, recalled from work with magnets in earlier grades. They then sketched how the lines of force affected the iron filings. Magnetic lines of force around a magnet dictate what forces the magnet will exert on other magnets, or on "induced" magnets, such as iron filings.
Next, students were instructed to carefully place the opposite ends of the two magnets across from each other (ours were color-coded to distinguish north from south) and hold them about a finger's width apart. They then placed the petri dish with the iron filings on top of the gap between the magnets and made observations and sketches of the iron filings pattern.
Finally, the students put the same ends of the magnets about a pencil width apart, put the petri dish over the gap, and made observations and sketches. …