• Project Description:
Our project is a mini windmill that uses wind energy to generate electricity. This process is achieved by creating a propeller and connecting it to a motor. This motor lies on a free rotating base that rotates above a stand (truss) that supports the whole mill. Rotating the base to face the direction of the wind is achieved by connecting a back rudder to the base.
• How does it work?
Electric energy generation starts when the wind rotates the propeller blades – that have a specific angle of attack- , thus rotating the motor that works as a generator giving AC power. Changing this AC power to DC one requires a simple bridge rectifier circuit that will supply us at the end a useful DC power which can be used to light a LED or charge NI-CD rechargeable batteries.
When the wind changes its direction it will attack the back rudder with a different angle thus allowing it to rotate to face the direction of the wind, so the propeller will be always facing the wind.
• Materials used:
➢ An old washing machine motor.
➢ 4 inch PVC pipe, about 1m long.
➢ MDF wood board.
➢ 3*3 cm cubic iron rod, about 5.5 m long.
Our windmill worked only in speedy winds but unfortunately we weren’t able to make it work in medium wind speeds due to more than one reason, which are:
➢ The design of the propeller blades which were homemade and we weren’t able to control and measure precisely the most convenient angle of attack.
➢ Absence of a gearing system.
➢ Absence of wind speedometer that would allow us to know precisely the wind speed, not by estimation.