Check whether micro-hydro is worth it
If you have a stream with a good drop, micro-hydro can run day and night and may beat solar for daily energy. It needs head (vertical fall), steady flow, and legal water rights.
How
- Measure head: use a professional survey, a topographic map or the hose method (lay a hose down the slope in sections and measure each height difference).
- Measure flow in the driest month with the bucket method for small streams or the float method for larger ones. Design with the lowest average flow of the year.
- Estimate power: watts is roughly net head in feet times flow in US gallons per minute, divided by about 10 (DOE) to 12 (ATTRA). Net head is gross head minus 5 to 10% for pipe losses as a first estimate.
- Treat under about 10 feet (3 m) of head as usually uneconomic, and under 2 feet (0.6 m) as probably unfeasible.
- Check water rights and permits with the legal module before spending on equipment: a separate right to use water for power may be needed.
- Share flow and intake plans with the water module so the stream also covers household and irrigation needs.
Safety: The float method is unsafe in fast or deep water. Never wade into a stream in flood.
Do these first
Sources
- Planning a Microhydropower System. US Department of Energy, Energy Saver, accessed 2026-11
- Micro-Hydro Power: Is It Right for My Farm?. NCAT ATTRA, accessed 2026-11