Hydraulic and shaft output power for a hydraulic turbine. Computes available water power Ph = ρgQH, shaft output Pout = η × Ph, and turbine power loss.
Turbomachinery · Turbineη = 0.8800 (88.0%)
Gross head minus penstock friction and other hydraulic losses
Power equations:
Where:
Turbine selection guide:
| Type | Head range | Flow | Typical η | Application |
|---|---|---|---|---|
| Pelton | > 200 m | Low | 85–92% | Mountain reservoirs, high-head |
| Francis | 20–700 m | Medium | 85–93% | Most common, dams and reservoirs |
| Kaplan | 2–40 m | High | 80–93% | Run-of-river, tidal barrages |
| Crossflow | 2–200 m | Low | 70–86% | Small hydro, micro hydro |
Hydraulic turbines convert potential (head) or kinetic (velocity) energy of water into mechanical shaft work. Efficiency is the product of hydraulic (ηh, flow-path losses), volumetric (ηv, leakage), and mechanical (ηm, bearing/seal) efficiencies. Large Francis and Pelton turbines can exceed 92% overall. Shaft power × ηgenerator gives the electrical output.