| Title | Fifteen Years (Mid-Life Time) of Wayang Windu Geothermal Power Station Unit-1: An Operational Review |
|---|---|
| Authors | Munggang H. PURNANTO, Anton PURWAKUSUMAH |
| Year | 2015 |
| Conference | World Geothermal Congress |
| Keywords | Wayang Windu, Geothermal Power Station, Operation, Maintenance, Optimization |
| Abstract | Wayang Windu Geothermal Power Station was constructed in 1997 with initial plan of 2 x 110 MWe. Unit-1 was completed in early 1999 but then mothballed due to the transmission line had not been ready yet. The Commercial Operation Date (COD) took place in June 2000. Unit-2 was postponed until 2007 because of the economic crisis. Wayang Windu Unit-1 was the first geothermal unit that designed with capacity of more than 100 MWe and the biggest single unit geothermal steam turbine in the world. Because of this condition, Wayang Windu Unit-1 was operated with full monitoring and careful handling, including 6 years warranty from Fuji Electric on the last stage blades of the turbine. After almost 15 years of successful operation, Wayang Windu Unit-1 indicates an excellent performance. The Availability Factor of the unit exceeds 96%. Even more, it reached 100% in 2010 and 2011 consecutively. The Plant Reliability Factor is never less than 99.5%. In term of Capacity Factor, Wayang Windu Unit-1 can generate electricity more than 95% to fulfill energy sales contract to Perusahaan Listrik Negara (State Owned Electricity Company). Forced Outage is minimized by maintaining the plant at the highest performance through implementation of Maintenance Management System (MMS). Several optimizations have been made to improve the Wayang Windu Unit-1 capacity. The initiatives that came from the Operational and Maintenance Team have enabled the plant to be operated beyond its designed capacity. The 110 MWe rated capacity is now improved and able to generate 114 MWe up to 116 MWe gross within Original Equipment Manufacturer (OEM) specification. The successful on balance of plant (BOP) improvement became criteria points to design Wayang Windu Unit-2, the identical unit with capability to interchange parts. These include modification of condenser nozzles, modification of turbine inlet pressure set point, and modification of cooling tower fan stacks. Improvement on SAGS design also contributes to provide high quality steam to minimize scaling problem that normally encountered in geothermal operation. This paper provides experience in operating and maintaining Wayang Windu Unit-1 as the first largest single flash geothermal power station. The plant performance after reaching mid-life time operation is presented. Various aspects that related with the capability to achieve operational excellence are also described. |