POWER FROM THE WIND WHERE THE NET DOES NOT REACH
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|The windmills below are constructed with the methods a private people can use. The aim has been to build windmills, that are long lasting and reliable in use, simple to construct and easy to service with out special knowledge of electronics. Blades of the windmills are fabricated using aluminium plate. In small windmills the loss of efficiency rate can be compensated using somewhat larger diameter, since wind is not a limiting factor. Belt driven transmission is silent and simple to fabricate for the desired gear ratio, it is later possible to adjust gear ratio and tune the mill and generator for optimal performance. The angle of the wings can be manually adjusted.|
This traditional 6 bladed wind mill has been in use since 2002 and it is producing power for lighting at 36 V. Multiwing turbine has proved to be more effective at very low wind speeds compared to more "modern" 3-bladed one. Mill starts to operate at very weak wind, even though at stronger wind the 3- bladed faster running turbine gives clearly higher power out put per swept area.
Due to the permanent magnet AC generator, some power is generated always when the mill runs. Under inland weak wind conditions enough power is generated for a few small lamps (total 100 – 150W) almost constantly most of the time. Maximal power is 1 kW. This windmill is erected at top of a 17 m high wooden pole.
This Ø 6,9 m windmill produces power even at inland conditions in kilowatts scale.
At daily winds (3-4 m/s) the power out put reaches some hundreds of watts, at somewhat windy weather (say 5-8 m/s) kilowatt or two and at strong wind 4 to 6 kilowatts.
As the area of the blades is smaller, load has to be switched off for this windmill to come in operation. Turbine must rotate properly for the wings to give proper torque.
Generator is permanent magnet type providing 3-phase alternating current. Load comprised of lights and heater is controlled with relays.