Chapter 8 – Hydro Energy

Chapter 8 – Hydro Energy

            Hydro energy is available in form of rivers and tidal waves in oceans. The technology of harnessing hydrogen energy in form of producing hydroelectricity is well established now. Among total electricity generation in world, 10.6 % corresponds to hydroelectricity. In India hydroelectricity has share of 11.4%.

8.1 Essential Elements of Hydro-electric Power Plant

·         Catchment area

·         Reservoir

·         Dam

·         Spillways

·         Sluice gate

·         Penstock

·         Turbine

·         Draft tube

·         Tail race

8.2 Classification of Hydro-electric Power Plant

Hydro-electric Power Plants may be classified into various categories on different basis.

8.2.1 Availability of water head

·         High head power plants (100 m and above)

·         Medium head power plants (30 to 100 m )

·         Low head power plants (25 to 80 m)

8.2.2 Nature of load

·         Base load plants (a definite amount of electricity is produced continuously to feed the grid)

·         Peak load plants ( may operate only at peak hour/ produce more electricity at peak hour)

8.2.3 Quantity of water available

·         Run-of-river plant without pondage (no storage of water and no control over flow rate)

·         Run-of-river plant with pondage (more useful in comparison to without pondage)

·         Storage type plants (reservoir of sufficiently large size)

·         Pumped storage plants (when water available for electricity production is less, water is pumped back from tail race to the reservoir using the extra energy available)

8.2.4 Capacity of plants

·         Regular size (above 25 MW)

Small Hydro Projects

·         Micro (up to 100 kW)

·         Mini (101-1000 kW)

·         Small (1-25 MW)

8.3 Environmental Impacts of Hydro Energy

Advantages

·         Renewable in nature

·         No cost of raw material at regular basis

·         No pollution

·         Dam increase the scenic beauty of the place

·         Lake may be utilized for water sports

·         Dam controls the flood

Disadvantages

·         Long time is needed to complete the project

·         Large area of land is needed

·         Evacuation of land needs mass population shift

·         Large amount of stored water affect the surrounding land