Free Online Micro-Hydro Power Calculator

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Run-of-River Micro-Hydro Power Output Calculator

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Head Loss: Total penstock (supply pipe) loss h_L = h_f + h_m, where h_f = f(L/D)(v²/2g) is Darcy-Weisbach friction loss and h_m = k_m·v²/2g covers entrance, bends, and valves. Net head H_net = H_gross − h_L.
Velocity: Check that velocity is reasonable for the available drop and pipe cost. Very low velocity may indicate oversizing; very high velocity can increase friction losses and water hammer risk.
Head Loss Target: Penstock (supply pipe) losses below 10% of gross head are generally economical. The optimal trade-off between pipe cost and lost power often falls around 4–6% where electricity is most valuable.
Efficiency: Typical plant efficiency η ranges from 0.70 to 0.85 for Pelton and cross-flow turbines common in micro-hydro. Use 0.75 as a conservative first estimate.
Annual Energy: Annual energy assumes continuous full-flow operation (8760 hours/year). Actual production will be lower due to seasonal flow variation, maintenance downtime, and load factor.