5 WIND POWER

5.1 History

5.1.1 Origins

5.1.1.1 Flour mills

The first wind powered machine was for grinding (milling) flour, apparently in 7th century Persia, operating on a vertical axis. Only after five more centuries did the familiar horizontal axis windmill appear in England, its realisation probably aided by water mill technology. Around the Mediterranean, simpler mills were adopted with triangular canvas sails attached to radial arms (Cretan design). The post mill and later the tower mill gradually developed in Northern Europe, until by the 18th century the latter had become the most sophisticated automatic machine of its day.

5.1.1.2 Water pumps and sawmills

 

Post mills were developed to drive waterwheel type pumps in the Netherlands for draining the polders from the 16th century, and these systems were also adapted to drive reciprocating saws to cut timber. The Cretan windmill has been used mainly for irrigation, driving a simple crank operated pump. But a new wind power technology emerged in 19th century USA, where water pumps to supply farms, and later the thirsty locomotives of the railroads, could be amply supplied by the new mass production industries. These were multibladed machines on wooden or steel towers, each capable of a substantial torque to drive a large piston pump.