Riam Kanan Hydroelectric Power Plant which located in South Kalimantan Indonesia operate since 1973 and have 3×10 MW capacity, dam storage type with earth fill dam, 42 m net head with 87 m3/s discharge, Francis runner, vertical shaft and 103 GWh/year energy production (14% – 34% to Grid). It is the most profitable plant in the Grid but it has a serious problem in dry season because the height of reservoir descends continuously. So, we can operate only one turbine unit from three turbine units. In that case, we have made a preliminary study about modification feasibility of Riam Kanan Hydroelectric Power Plant. We propose a modification of one turbine unit from an ordinary turbine type to a reversible pump-turbine that can operate as either a pump or a turbine. At times of low electricity demand (e.g. during the daylight in Indonesia) cheap electricity is used to pump water from the low reservoir to high reservoir. For that purpose peak load energy is produced by water previously store in the high reservoir, so at times of high electricity demand (e.g. during the night in Indonesia) we can operate two or three turbines. The sets of stage is of the vertical and the Francis type hydraulic machine operate as turbine or pump, the electrical machine to which they are coupled operating respectively as generator or motor. The Power Factor is 0.9 running as generator and 0.95 as motor. The scope of works is runner replacement, modification of stay vanes, draft tube modification, generator modification, shaft modification, control system modification and modification of penstock. We’ll modify penstock because we have only one penstock. The power for the unit that operates as a pump is supplied by the power station it self. For that purpose we need two penstocks which can be used simultaneously. From simulation result, we get operating time for pumping is 7 hours and for generating (at 90% full load) is 6 hours. Duration of modification is short relatively. This modification also can lengthen the lifetime of the hydroelectric power plant. However the main advantage of this scheme lies in it being to store inexpensive off peak energy in readiness to meet peak load demand that normally require more expensive sources (e.g. diesel power plant or coal fired power plant in the grid).
Paper lengkap-nya telah dipresentasikan di forum The 16th Conference of the Electric Power Supply Industry (CEPSI) 2006 di Mumbai India pada tanggal 07 November 2006 oleh mazelisonk