HYDROELECTRIC POWER GENERATION

Hydroelectric power generation involves the storage of a hydraulic fluid, water, conversion of the hydraulic (potential) energy of the fluid into mechanical (kinetic) energy in a hydraulic turbine, and conversion of the mechanical energy to electrical energy in an electric generator.

The first hydroelectric power plants came into service in the 1880s and now comprise approximately 20% (875 GW) of the worlds installed generation capacity (World Energy Council, 2010). Hydroelectricity is an important source of renewable energy and provides significant flexibility in base loading, peaking, and energy storage applications. While initial capital costs are high, the inherent simplicity of hydroelectric plants, coupled with their low operating and maintenance costs, long service life, and high reliability, makes them a very cost-effective and flexible source of electricity generation.

Especially valuable is their operating characteristic of fast response for start-up, loading, unloading, and following of system load variations. Other useful features include their ability to start without the availability of power system voltage (black start capability), ability to transfer rapidly from generation mode to synchronous-condenser mode, and pumped storage application.

Hydroelectric units have been installed in capacities ranging from a few kilowatts to nearly 1 GW. Multiunit plant sizes range from a few kilowatts to a maximum of 22.5 GW.

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