The country which is known as “The Ring of Fire”, that starting from the northern tip of Sumatra and passing through Java, Bali, Nusa Tenggara, Sulawesi and Moluccas islands. Indonesia has 500 volcanic cones and more than 200 volcanoes, in which 129 are active. Whilst the volcanoes and earthquakes common to this geological zone can be highly destructive, this condition also have a positive side such as gives a big potential of geothermal energy.
Currently, the geothermal energy resources that have been confirmed span from Sumatra to East Nusa Tenggara and have the potential to produce up to 29,000 MWe of electricity across 299 locations or equal to 40 percent of the total global potential geothermal energy resources in the world. Half of this potential is found in Sumatra and Java.
Early geothermal exploration in Indonesia was carried out by Dutch Colonial in 1918-1928 in Kamojang, West Java. Until the year of 1926, Dutch has made five geothermal exploration drillings, but the one succeeded in producing steam was only wells KMJ-3 with the depth of 66 meter. Until now KMJ-3 still produces natural dry steam.
Sixty eight years later, on January 1983, Kamojang was inaugurated as the first Geothermal Production Field in Indonesia. And then is followed by other geothermal fields that start to produce electricity, such as Mt. Darajat (1994), Mt. Salak (1994), Mt. Sibayak (1997), Mt. Dieng (1998), Mt. Wayang Windu (2000), Lahendong (2001), Ulubelu (2011), Ulumbu (2012).
However, while geothermal resources offer the potential of 29,000 MWe of electricity, only 4.6 percent (1,345.3MWe) has been developed in the past 30 years, since Kamojang was launched as the first geothermal power plant in Indonesia. The progress on its rate of production, however, is occuring at a very slow pace. At present Indonesia, even though as the third largest electricity producer, has one of the lowest elctrifications rate (66 percent) in Asia.
The development of Indonesia’s geothermal energy potential is important as the country’s electricity demand increases by 7-8 percent annually. In accordance to that, Strategic Plan of the Government of Indonesia, by 2025 Indonesia aims to produce more than 9,000 MWe of geothermal power, this would account for 25 percent of the total geothermal energy.
INDONESIA GEOTHERMAL EXPLORATION AND DEVELOPMENT
During the Dutch colonial era, JB. Van Dijk proposed to harness geothermal energy in Kawah (crater) Kamojang, West Java. It is the starting point for the geothermal development history in Indonesia. Coincidently, the event coincided with the beginning of harnessing the geothermal steam to generate electricity in Larderello-Italy.
Years of 1918–1928
At the time five test borings were drilled in Kawah Kamojang (West Java) geothermal field, the third well (KMJ-3) being the first that was successful with the depth of 66 meters. Until now KMJ-3 is still discharging superheated dry steam to the atmosphere. Since 1928, Indonesia’s geothermal activity practically stopped and only resumed in 1964.
Years of 1970’s
From 1971 to 1981, investigation of geothermal resources was conducted jointly by Geological Survey of Indonesia, (GSI-Bandung) and New Zealand (NZ) Government, USA, Italy and Japan.
A more comprehensive investigation was carried out in Kamojang involving geological mapping, geochemical, and geophysical. In the same year, six geothermal wells had been drilled in the Dieng Mountains, with depths of 613 meters. Unfortunately, none of them had found geothermal steam. In that year, Cisolok, West Java, and the Kawah Ijen, East Java, also had an investigation conducted.
Then in 1974
PT. Pertamina (State Oil Enterprise) and PT. PLN (State Electrical Enterprise) collaboration with NZ Government was more intense to carry-out geothermal surveys in Kamojang for the development of 30 MWe power generation, and completed them in 1977. In addition, Pertamina was also developing two monoblocks with a total capacity of 2 MWe in the field of Kamojang and Dieng. Inauguration was made on November 27, 1978 for the Kamojang monoblock and on May 14, 1981 for the Dieng monoblock. Kamojang Geothermal power plant (PLTP) itself was inaugurated 5 years later. The year of 1974 was a significant development year in Kamojang, when Pertamina with PLN developed the geothermal field with geothermal exploration wells with a depth of 600 meters which produces geothermal steam with bursts up.
Outside Java, geothermal resources were investigated in Bedugul-Bali, Lahendong-North Sulawesi, Lampung and Kerinci (Sumatra). Survey teams, GSI-PLN, collaborated with NZ Goverment to visit geothermal fields in Lahendong (1971), Bedugul-Bali (1974), Lampung and Kerinci (1977/1978).
Adapted from pangea.stanford.edu