Microhydro Sytems - Power from falling water !
If you have a seasonal creek within a few hundred feet from your house or power shed a microhydro system is for you. For those who are lucky enough to have a good site, hydro is really the renewable energy of choice. System component cost are much lower, and watts per dollar return is much greater for hydro than for any other renewable energy source. The key element is a good site is the vertical distance the water drops. A small amount of water dropping a large distance will produce as much energy as a large amount of water dropping a small distance. The greater the head (elevation for water to drop) the more power your water turbine will produce. The water turbine could easily handle all of your power needs (except heating loads) for with the right site microhydro is constantly producing electricity all day and night !
How does a Microhydro system work?
The basic parts of a microhydro systems is the pipeline (called the penstock in the trade), which delivers the water to a manifold and then to the turbine, which transforms the energy of the flowing water into rotational energy. The turbine transforms the rotational energy into electricity. The regulator which controls the water turbine and dumps the excess energy the turbine creates, depending on regulator style, and the wiring, which delivers the electricity. Our micro-hydro turbines also require a battery bank, which stores the DC electricity that the water turbine produces. Most systems also use an inverter, which converts the DC electricity into AC electricity to power your house hold electronics and appliances.
Output voltage is user-settable from 12 to 48 volts. Available in two or four nozzle turbines, the stream engine is supplied with universal cut-to-size nozzles of 1/8 – 1 inch. Output can reach 1000 watts continious.
Power Output & Site Assessment
To determine the power available at a site, head and flow measurements must be taken. Flow is the rate at which water moves, measured in liters per second (l/s) or gallons per minute (gpm). This can be measured by channeling the water into a pipeline, then into a container of a know volume, noting the time it takes to do so. A weir can be used to measure flows in larger streams. Head can be measured by using a transit, by sitting along a level, or by using a pressure guage at the end of the pipeline. An altimeter can also be used, so long as it is accurate, and sufficiently sensitive.
It is most important to keep in mind the output can only be accurately determined if head and flow measurements are made correctly, so care should be taken during this process.
Stream Engine Output (Watts Continuous) Head Flow Litres/Sec - Gallons/Min Metres (Feet) 0.63 (10) 1.3 (20) 2.5 (40) 4.7 (75) 6.3 (100) 9.5 (150) 3 (10) 50 90 120 6 (20) 40 100 180 230 350 15 (50) 45 100 220 400 550 800 30 (100) 80 200 500 940 1100 60 (200) 150 400 900 1500
