Hydro power, electricity from running water, can be one of the most cost effective renewable sources if you have a site with the two basic requirements – head and flow. Head is the vertical distance the water falls and flow is the amount of water flowing.
Rocky Grove designs and installs micro hydro systems, which are small hydro power systems. The most common micro hydro systems are the type called high head systems. These systems use the pressure created by the vertical fall of water captured in a pipe. Vertical falls of 50 feet or more will make usable power with only 10 – 15 gallons of water flowing per minute. These systems most commonly use a pelton style water wheel which is turned by the pressure and flow of the water. This wheel in turn spins an alternator to produce power continuously 24 hours a day.
Low head systems can use vertical drops of 10 – 50 feet but in turn need much more water flow. To capture power from 10 feet of head a site must have around 1000 gallons per minute of flow in the lowest flow time of the year. With more head less water will be needed, but more water will produce increasing amounts of power.
Hydro systems must be designed specifically for your site, and they can require federal paperwork. Once developed, though, hydro power systems can produce the most cost effective renewable energy.