The Impact of Sedimentation in Reservoirs on Performance Operation of Hydropower: A Case Study Sutami Hydropower Indonesia

This paper describes the sedimentation rate and the productivity of hydropower. Sedimentation of reservoirs has become a serious threat to the operation of the reservoir and hydroelectric power in Indonesia. Sedimentation rate in Indonesia resulted in a reduction in storage capacity of reservoirs, hydropower operations are disrupted, and abrade the hydropower turbines. Reservoir sedimentation in Indonesia has reduced catchment reservoirs reached 1.28 % per year. Reservoirs with small capacities (less than 200 million m3) suffered a loss of storage capacity which is about 2.05 %. Reservoir with a capacity of over 300 million experience loss of storage capacity which is 0.62 %. Expected loss due to sedimentation in 284 large dams in Indonesia shrink water volume reached about 12.4 billion cubic meters. Economically it is converted to 84 million dollars per year. Based on the observation and analysis of historical data to reservoirs and Sutami hydropower it was found that the rate of sedimentation in the Sutami reservoir is 4.76 million m3 / year so that the reservoir capacity remain 54 % in 2011. Nevertheless, the production capacity of Sutami hydropower is still very good, indicated by the capacity factor 34 % -76 % range, and the average 50.5 %. High rate of sedimentation in the Sutami reservoir is not provide significant impact on the productivity of hydropower, this is caused by sediment distribution pattern of horizontal and evenly on all elevations.