ABSTRACT
In 1891, Professor Poul la Cour started a series of experiments for a rational utilization of wind power for the generation of electrical energy. At first Poul la Cour used the electric current for electrolysis of an aqueous solution of sodium hydroxide. The developed oxygen and hydrogen were stored in gasometers and led through lead pipes to the place of consumption. Measurement of wind power proved to be done best by a cup-anemometer mounted on a pole at the same level as the mill axle and at a suitable distance from the mill. Though the efficiency of windmills is far from being of the same interest as steam turbines and diesel engines, comparisons between the various types of mills may, however, be of some interest. In the case of adjustable multi-blade mills regulation is accomplished by the wind blades swinging open when the wind pressure becomes dangerous. Propeller mills are also self-regulating.
