Wooden water wheels working on the Yellow River in the town of Lanzhou, China. With diameters ranging from 10 to 20 meters, they are used to pump irrigation water.

Mankind has been using water, as well as its energy, for a very long time. Water can be drunk, it sustains fish that can be eaten, one can wash in it and bathing can be very relaxing. These are obvious uses but very early on people realized that water can also be harnessed for energy. The first machines to use energy from water were simple water wheels which helped with some of the heavy work.

The earliest sources mentioning water powered machinery come from the ancient Greeks and date back to approximately 4000 BC. In those times, people used water energy mainly for grinding grain and supplying water to irrigation canals. With time, water energy started driving sawmills, trip hammers and various other machines. Finally people started using it to power electric generators. Things got a lot simpler and more efficient once the water turbine was invented. As the turbines were connected to dynamos, the first hydroelectric power plants came about.

14 pictures

14 pictures