Hydro Electric Power Plants

    1. Run-of-river hydropower plants utilize the inflow directly for electricity supply without significant storage capacity. In some cases changes in water level can be utilized for storage purposes to a limited degree. This operating mode is referred to as hydropeaking.

    2. Impoundment hydropower plants collect the inflow in reservoirs with capacities that, in many cases, are large enough for generating at full load for several months. Inflow and generation can thus largely be decoupled. The storage hydropower plants only use part of the water impounded immediately.

    3. Pumped storage hydropower plants have no significant inflow but have a reservoir that is filled from a lower reservoir using pumps. The potential energy of the water stored at the higher level is used for electricity supply, usually to cover peak demand.

Illustration 1: Tehri Dam, Uttarakhand

Illustration 2: Pong Dam, Himachal Pradesh