Gross head: 135 feet (41 meters)
Measured flow: 25 to 100 gpm, (1.6 to 6.3 l/s)
Pipeline length: 900 feet (274 m)
Gross power: 350 to 1,200 watts
A DC, battery-based system with an inverter is the best choice for a hydro site with the above parameters. If an AC turbine were used, peak usage would be limited to about 1,200 watts at peak flow. This peak power figure would not be sufficient to run the combined electrical loads of most households. Installation of a turbine with DC output would allow energy storage in a battery bank, and an inverter or inverters would be able to provide as much instantaneous power as was required by the residence.
With a design flow of 100 gpm, using 3-inch diameter PVC pipe would result in a head loss of 2.33 feet per 100 feet of pipe, for a net head of 114 feet (35 m), and a maximum power output of about 1,200 watts at maximum flow. Over a 24-hour period, this system would produce 28.8 KWH. As summer approached and the flow rate dropped off to the site’s minimum of 25 gpm, the same 3-inch pipe would result in a net head of 133 feet (41 m), and a power output of about 350 W, or 8.4 KWH per day. This would typically be enough energy to power all the electric appliances in an efficient home, excluding cooking, space heating, and water heating.
