Students will need to locate working windmills and speak with property owners to gain access for observation and data collection. Ideally, the student should find windmills operating with one, two and three-bladed rotors of various blade lengths. Hypothesize which type of windmill is most cost-effective to maintain and most profitable in storage of usable energy. Over a period of six weeks, observe and record the wattage rating of energy stored in each windmill and consult with windmill owners to calculate operation and maintenance costs of each windmill type. Record findings on a graph to support efficiency conclusions.
Although many windmills are made from metal and motor-powered, green-minded students can create their own miniature windmill from wood that runs on magnetic power. Construct the base from a 6-inch square block of wood. Attach two side mounts made from 2-by-4 inch beams cut to 6 inches tall and curved at the top. Drill a small hole near the top of each piece to hold the spindle. Make an armature by shaving a wood block into a cylinder, hollowing out the center and drilling a hole through the midpoint of the base. Store eight donut magnets inside with alternate poles facing out. Cap off with a wood disc of the same diameter and wrap in a strip of metal. Cut two pieces of plywood into C shapes and hollow out the inside of the C curves to fill with magnetite sand and wrap curves in enameled copper wire. Hold the armature between the side of the base and drive a metal shaft through the drilled holes. Wrap the C curves around the armature. Build a 3-blade prop using 1-by-4 inch beams that is 4 feet in diameter. Attach to a wood block with a wooden dowel and adhere to a 2-by-4 inch beam shaft with epoxy glue.
Home school or public school students with Internet access should research various design plans for building model windmills that can easily be adapted. Build two identical windmills using the same construction plans, with the exception of mounting one windmill's blades vertically and mounting the other set of blades horizontally on the shaft. Connect each windmill to an LED light and set both in front of a high-powered fan to simulate wind. Observe the light illumination and record data to determine whether the blade position affects the amount of energy a windmill is able to collect.
Build several identical model windmills and connect each one with wire and crocodile clips to different-sized batteries, LED light, incandescent flashlight bulb and other objects requiring electrical power. Set three-speed fans of identical power and size in front of each windmill set on low speed. Determine whether the windmills produce enough power to run each item. Increase the speed to medium and record observations. Repeat the experiment on high fan speed. Use the data collected to propose the effectiveness of windmills as a source of electrical energy.