Low-Head Hydro Calculator
Power and annual energy from head × flow × efficiency — low-head site (<10 m) presets.
Low head needs volume: 4 m × 1.5 m³/s ≈ 38 kW. Old mill weirs, barrage gates and tidal creeks live in this class — civil cost per kW decides feasibility more than the turbine.
Low-head site (<10 m): every metre of head and every litre per second is power — 10 m × 100 L/s at 65% efficiency ≈ 6.4 kW, day and night. Hydro's magic is the availability: unlike solar's ~20%, a good stream runs 60–90% of the year.
Engineering estimate from published standards and typical equipment data. Site conditions, equipment datasheets and measured data govern the real result — confirm with a qualified engineer.
Use the free Low-Head Hydro Calculator online — Power and annual energy from head × flow × efficiency — low-head site (<10 m) presets. Runs instantly in your browser: no signup, no upload, mobile-friendly.
About Low-Head Hydro Calculator
Low head needs volume: 4 m × 1.5 m³/s ≈ 38 kW. Old mill weirs, barrage gates and tidal creeks live in this class — civil cost per kW decides feasibility more than the turbine.
How to use Low-Head Hydro Calculator
- 1Enter net head and the dependable (dry-season) flow.
- 2Set system efficiency and a realistic availability factor.
- 3Read kW, annual kWh and the energy's value.
Why use Low-Head Hydro Calculator?
- ✓P = ρgQHη — transparent physics with site-class presets
- ✓Availability-weighted annual energy, not nameplate dreams
- ✓Dependable-flow guidance: dry-season numbers decide
- ✓Homes-powered framing for community projects
Frequently asked questions
How much power can my stream generate?+
P(kW) = 9.81 × flow(m³/s) × head(m) × efficiency. Ten metres of drop with 100 L/s at 65% efficiency makes ~6.4 kW — continuously, day and night. Hydro's edge over solar is the hours: 60–90% availability versus ~20% — small kW, huge kWh.
What's more important — head or flow?+
They multiply, but head is the better friend: high head means small water, small pipes, small turbines (cheap Pelton wheels), while low-head sites need big flows and big civil works per kW. The classic rule: find the drop first, then measure the water.
Which flow measurement should I use for design?+
The dependable dry-season flow — the stream's worst honest month — not the monsoon spectacle. Design flow above dependable flow buys capacity that idles most of the year. The flow-measurement tools on this site (bucket, float, weir) make the measurement a weekend job.
What does micro hydro cost compared to solar?+
Site-dependent: ₹1.5–4 lakh/kW installed for good micro sites (vs solar's ~₹0.5/kW) — but hydro's 3–4× capacity factor and 30+ year civil life flip the per-kWh economics at decent sites. Run this tool's annual kWh against solar's for your location and the comparison settles itself.
Embed Low-Head Hydro Calculator on your website
Want Low-Head Hydro Calculatoron your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
<iframe src="https://tooljolt.com/tools/low-head-hydro-calculator" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="Low-Head Hydro Calculator — ToolJolt" loading="lazy"></iframe>Related Energy tools
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