Component of a HydroPower Plant..2

Intake Structure

Storage Reservoir: Constructed by building a dam/barrage across the river.

Escape structure or spillway: to allow the excess water to pass.

Diversion structure: are to divert the water for the taking it for power generation

Desilting basin: to remove the silt

Trash Rack: to prevent the debris, wooden blocks, stones etc., entering into the power house.

Gates: Intake gates, spillway gates, stoplogs etc., to regulate the flow

Water Conductor System

Power Canal: a small water channel/duct used to take the water upto the tunnel intake

Tunnel: a underground water conducting passage.

Surge Shaft or Surge Tank: a vertical water storage structure used to store water in case of emergency (prevent water hammer)

Drop shaft a vertical underground water conducting passage

Pressure Shaft a tunnel with high pressure of water used a water conducting passage.

Penstock: a large diameter steel/concrete pipes used to take water from the tunnel or forbay to powerhouse

Penstock Protection Valve (Butterfly Valve): used to isolate the water conducting system with the powerhouse in case of penstock repair or failure

Components of a HydroPower Plant

1. Intake Arrangement

• Storage Reservoir
• Diversion Structure or Spillway
• De-silting Basin
• trash Rack
• Gates

2. Water Conductor System

• Power Channel/Duct
• Tunnel
• Surge Shaft or Surge Tank
• Drop Shaft
• Pressure Shaft
• Penstock with Penstock Protection Valve (Butterfly Valve)

3. Power House

A. (Mechanical Component)

• Distributor / Spiral Casing
• Spherical Valve or Main Inlet Valve
• Turbine
• EOT Crane

B. (Electrical Component)

• Generator
• Transformer
• Switchyard
• Transmission Line

C. (Powerhouse Auxiliaries)

• Cooling water system
• Compressed Air System
• De-watering System
• Drainage System
• Air Conditioning System
• Control & Monitoring System
• Fire Protection System

The above components shall be discussed in details in forthcoming posts.

Types of Hydro Power Projects

• Run-Off the river Project

–Normal flow in a river which otherwise is un-utilised is used for generating power

–May require small storage facility

–Project based on stipulated dependability (90 %)

• Dam Storage based Projects

–releases of dam are passed through the generating units resulting in added benefits along with irrigation needs

–may cater as base load plant also

• Canal Based Projects

–utilises the drop (also sometimes called rapids) in a stretch of canal

–requires a diversion canal arrangement

• Pumped Storage Plants

–concept based on differential tariff structure

- peak time tariff and normal tariff

–Pumps water utilising power available (at lower tariff) during normal hours to a higher altitude

–utilising this storage, and generates power during peak time (charged at higher tariff)

• Tidal Projects

–utilises the energy of waves

Characteristics of Hydro-Power Plant

General :

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• Renewable Energy Source, no fear of depleting fuel.

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• Minimum expected availability - 95 %

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• Environment Friendly

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• No Pollution

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• Requires minimum Submergence (for Run-off river projects)

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• Multipurpose projects are possible i.e, irrigation, flood control, fishery, Tourism, etc. apart from Power Generation

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• Smaller capacity project feasible (unlike economy of scale to be considered for thermal Project)

O & M aspects :

• Peak load Plant

• Part load operation is possible- with reasonable higher efficiency (in the range of 75-85 %)

• Low Operating and Maintenance Cost

•Requires very less auxiliaries system as compared to Thermal Power Projects.