6.1.2 SHORT HISTORY

6.1.2.1 The origins of hydropower

Water power has contributed to the development of mankind since Biblical times. References to the use of waterwheels for milling, pumping, and other functions date back to 300 BC in Greece, although they were probably in use long before that time. In the years between these early uses of the waterwheel and the onset of the Industrial Revolution, running water and wind were the only available sources of mechanical power, other than that generated by animals. Improvements in power recovery from flowing water were steadily introduced as exemplified by the sophisticated waterworks designed in the 1600s for the palace of Versailles outside Paris, France. This system had a capacity equivalent to an estimated 56 kW of power.

6.1.2.2 Early developments in the field of hydro

Water power systems, and eventually hydroelectric generating plants, were developed from attempts at improving the efficiency of the waterwheel. Much of the early research took place in France because at the beginning of the Industrial Revolution, France, unlike many nations did not have access to large coal deposits. The French relied heavily on their water resources to generate the energy needed for industrial expansion. In fact, waterpower is still called houille blanche, or white coal, in France.

Much theoretical work was done during this period by mathematicians and engineers such as Bernard Forest de Belidor, John Smeaton, Jean Victor Ponceler, Leonhard Euler, Claude Burdin, and Benoit Fourneyron. Their work resulted in significant improvements in turbine efficiency and laid the ground work for the development of modern turbines of the Francis, Kaplan, and Pelton type. As an example of the progress achieved, it is worth mentioning that the original vertical-mid turbine designed by Belidor attained an efficiency of 15 to 20%. By the mid 1850s this rose to 60 to 70%. The Francis and Kaplan turbines, which are the modern counterparts of the Belidor turbine, now achieve efficiencies of 90 to 95%.

During the 1870s electricity was introduced as a popular source of energy to the public thanks to Thomas Edison and the dynamo. Not too long after that the dynamo was coupled with the waterwheel and the technology of hydroelectricity was born. The first hydroelectric unit in the United States is reported to have been a 12.5 kW plant installed in 1882 on the Fox River at Appleton, Wisconsin.

Small-scale hydropower was the most common way of generating electricity in the early 20th century. In 1924 in Switzerland, for example, nearly 7000 small scale hydropower stations were in use. The improvement of electricity distribution by means of high voltage transmission lines much reduced interest in small scale hydropower. Renewed interest in the technology of small scale hydropower started in China. Estimates say that between 1970 and 1985 nearly 76,000 small scale hydro stations have been built there!