Located on the Ring of Fire and home to more than 200 volcanoes, Indonesia is estimated to have about 28 GW of geothermal potential for power generation, which is about 40 percent of the geothermal potential for the entire world. 41 volcanoes are found on the island of Java alone, providing abundant geothermal resources and holding the highest potential for energy production.
Fittingly, this reflects the locale’s demand for energy. Home to 135 million inhabitants — about 60 percent of Indonesia’s population — Java is one of the most densely populated areas in the world. To meet energy demand, geothermal plants have been expanding to increase output.
The Wayang Windu Geothermal Power Plant sits in the heart of this activity in Pangalengan, West Java. A Star Energy plant, Wayang Windu is a flash steam power plant listed as one of the largest in the world. Currently a two-unit site with exploration for unit 3 underway, Wayang Windu has a total installed capacity of 227 MW. The first unit was completed in 1999 and has been producing at full capacity of 110 MW since 2000. The second unit, with capacity of 117 MW, was been online since 2009.
While the need for geothermal energy is clear, construction or expansion of plants, wells and the piping systems that connect them often presents several challenges that must be considered in the design phase.
Piping System Design Challenges
Located in a highly active seismic zone, Wayang Windu experiences shifts in the ground, both subtle and extreme, on a daily basis. The power plant’s buildings and infrastructure are designed to absorb this movement, but other necessary components — long stretches of outdoor piping, for example — don’t afford the same flexibility. In addition to seismic movement, outdoor piping systems are subject to thermal expansion and contraction that must also be accommodated.