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Hydroelectric schemes by hydraulic characteristics

Short answer

Run-of-river (RoR) uses river flow directly with daily pondage for peaking; storage uses a dam reservoir for firm year-round power; diversion conveys water via canal/tunnel to a downstream powerhouse to gain head; dam-toe places powerhouse at dam foot; pumped storage uses two reservoirs for peak/off-peak; tidal is unsuitable for Nepal.

Describe various types of hydroelectric schemes based on hydraulic characteristics.

Based on hydraulic characteristics (how water is brought to the turbine), hydropower schemes are:

1. Run-of-river (RoR) scheme

  • Uses river flow directly without significant storage; a small weir diverts the water. Output follows the river flow.
  • Variants: RoR with daily pondage (peaking RoR).

2. Storage (reservoir) scheme

  • A dam stores monsoon flow and releases it as needed. Gives firm power and can regulate the river seasonally or annually.

3. Diversion (canal/tunnel) scheme

  • Water is diverted from a weir by a canal or tunnel along the river to a powerhouse downstream, so that the head is gained over the length of the river.
  • Types: free-flow canal, pressure tunnel.

4. Dam-toe (dam-based) scheme

  • Powerhouse is at the foot of the dam, and the head comes from the dam height.

5. Pumped storage scheme

  • Two reservoirs; water is pumped up in off-peak time and used in peak time.

6. Tidal scheme (also considered)

  • Uses the rise and fall of the sea; not suited for Nepal.
 Diversion RoR          Storage dam-toe
 weir--canal--forebay   reservoir | dam
              | penstock          |__ PH
              PH

✓ Answer checked by Claude Opus 5.5 (high effort)

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