A second turbine-generator unit has been added to the Wayang Windu geothermal field in West Java, Indonesia. The 117MW unit more than doubles the plant’s output, adding to the existing 110MW turbine. At a total cost of around $200m, Wayang Windu is now the largest geothermal power plant in Indonesia. The field is itself Indonesia’s largest geothermal development, and one of the largest in the world.
At the peak of construction of Unit 2, there were more than 1,500 workers on site. The unit was powered up to 30MW in December 2008, selling its first electricity into the PLN (Perusahaan Listrik Negara) West Java high voltage grid. Full commercial operation began in March 2009.
The plant is being expanded further with the addition of a third unit. The new 127MW unit is expected to come on stream by mid-2013, bringing the total plant capacity to 354MW. The new unit is being partially funded by the proceeds, received from a $350m bond issue made in 2010.
The plant is being expanded further with the addition of a third unit. The new 127MW unit is expected to come on stream by mid-2013, bringing the total plant capacity to 354MW. The new unit is being partially funded by the proceeds received from a $350m bond issue made in 2010.
Another two units are planned to come on stream by 2010, bringing the total plant capacity to 500MW at an additional cost of around US $450m.
Wayang Windu powers 117MW geothermal turbine
Star Energy acquired the 110MW Wayang Windu geothermal plant in November 2004. It owns the plant through its 100%-owned subsidiary Magma Nusantara Limited (MNL).
Aecom provided the engineering and design services for Units 1 and 2.
MNL appointed Maunsell to provide engineering review, design and supervision consulting services for Unit 2 construction and development, excluding the geothermal wells themselves.
Maunsell also provided support for administration and cost management, QA/QC, certification of construction status, sub-surface advisory services, and training.
Much of the preparation and infrastructure works for Unit 2 was completed as part of Unit 1 development between 1997 and 2000.
Besides the 117MW geothermal turbine generator unit, Unit 2 has auxiliary plant including condenser, cooling tower, non-condensable gas extraction facilities and H2S removal system. A steam above-ground pipeline system (SAGS) connects the new geothermal wells to the turbine. The plant-wide distributed control system has also been extended and integrated.
World’s largest single cylinder turbine
Unit 1 began operation in 2000, with power equipment supplied by Fuji Electric. At the time, the 110MW turbine was the world’s largest single cylinder machine. There are two-phase fluid pipelines with central separators, and integrated pressure control. Since startup, the generator has supplied 110MW at night and 105MW in the day into the State Electricity Company PLN’s grid.
The plant uses flash steam technology, with the steam generating electricity by driving the turbine directly. The steam is produced at more than 300°C, and contains virtually no pollutant gasses or CO2. Wayang Windu is the world’s most efficient geothermal facility. The first Unit 2 development well MBD-5 was also found to be the largest dry steam well in the world at more than 40MW.
MNL has a Joint Operating Contract with Pertamina Geothermal Energy (PGE), and an Energy Sales Contract with Pertamina and PLN to supply up to 400MW to PLN for 30 years. The plant feeds Java, Madura and Bali.