ABSTRACT
The wind is a free, clean, and inexhaustible energy source. It has served humankind well for many
centuries by propelling ships and driving wind turbines to grind grain and pump water. Denmark was
the first country to use wind for generation of electricity. The Danes were using a 23-m diameter wind
turbine in 1890 to generate electricity. By 1910, several hundred units with capacities of 5 to 25 kW were
in operation in Denmark (Johnson, 1985). By about 1925, commercial wind-electric plants using two-
and three-bladed propellers appeared on the American market. The most common brands were
Wincharger (200 to 1200 W) and Jacobs (1.5 to 3 kW). These were used on farms to charge storage
batteries which were then used to operate radios, lights, and small appliances with voltage ratings of 12,
32, or 110 volts. A good selection of 32-VDC appliances was developed by the industry to meet this
demand.
