Analysis of water source availability estimation for picohydro electric generator (Case study in Gunung Tua village, sub district of Cijambe, district of Subang, Province of West Java, Indonesia)

The Picohydro with 2500 Watts of output power designed by The Center of Appropriate Technology Development - Indonesian Institute of Sciences (B2PTTG-LIPI) has been implemented in Gunung Tua Village, Sub District of Cijambe, District of Subang, West Java Province in 2011. At electric generator installation by water power, an analysis of water availability estimation for the purpose above is needed. One alternative of method to analyze it is by using Curve Number method. In other hand the result of water availability calculation can be used as reference of calculation of waterworks construction and also determination of level of electric generator capacities that will be used. The value of runoff curve number is 78. The highest drainage occurred on February as high as 3517.38 litres/second and the lowest drainage occurred on August as high as 340.67 litres/second. The area of watershed at the activity location is 960 hectares. With the height of waterfall 10 m and assumption of generator efficiency picohydro as high as 50%, will obtain energy electrics as high as 175.85 kWatt on February and 17.05 kWatt on August. When the water source comes from the absorbed rain water by the ground with maximum retention potency is 6.67 and delivered with the shape of ground water that goes to water channels, which is water source to move the picohydro turbine, then the highest water stream on February is 235.66 litres/second with acquirement of electric energy as high as 11.8 kWatt, and the lowest on August is 22.82 litres/second with acquirement electric energy as high as 1.145 kWatt.