May 30 2023

The Beginning

Indonesia is the second-largest geothermal energy producer in the world, after the US, with a total installed capacity of 2356 MW as of January 2023 according to ThinkGeoEnergy. The story of geothermal in Indonesia began in 1918 when Dutchman JB Van Dijk noticed and reported the geothermal potential in the Kamojang area in West Java. Inspired by the successful geothermal development in Larderello in Italy, a Dutch company drilled five shallow wells between 60 to 128 meters deep from 1926 to 1927 in the Kamojang area. One of them, the well KMJ-3, was successful and is still producing steam today. This discovery established the Kamojang area as having tremendous potential for geothermal energy development.

Subsequently, in 1974 Pertamina began exploring and assessing the geothermal resources in Kamojang in earnest with the cooperation of New Zealand.Then in 1978, the first geothermal power station in Indonesia came into production at Kamojang with an installed capacity of 0.25 MW.

Today the Kamojang power plant consists of 5 power stations with a total installed capacity of 235 MW making it one of the biggest geothermal power plants in Indonesia. Since the establishment of the Kamojang plant, many companies started to develop geothermal resources in Java, Sumatra, and the Eastern part of Indonesia. Here are the seven geothermal operators in Indonesia.


Pertamina Geothermal Energy is the first and the most active geothermal company in Indonesia. It constructed the first geothermal plant in Indonesia, the Kamojang power plant in 1978 with the cooperation of New Zealand.

PGE operates and supplies steam to 21 geothermal power plants in six work areas, namely in Kamojang, Sibayak North Sumatra, Ulubelu, Lahendong, Lumut Balai South Sumatra, and Karaha West Java. The total installed capacity of the 21 power stations is 672 MW. Besides these direct operations, PGE has joint operation contracts with several geothermal operators in the operations of their power plants with a total of 1205 MW installed capacity.

Pertamina Geothermal Energy became a public company on February 24, 2023. With the 594 million USD of fresh funds it received from the IPO, PGE plans to add 600 MW of installed capacity by 2027, according to its CEO Mr. Ahmad Yuniarto.

Here are the geothermal plants which PGE operates

  • • 235 MW Kamojang Unit 1, 2, 3, 4, 5 in West Java (Note: Supplying steam to Units 1, 2, and 3 operated by PLN)
  • • 120 MW Lahendong Unit 1, 2, 3, 4, 5, 6 in Sulawesi
  • • 5 MW Lahendong Binary in Sulawesi
  • • 110 MW Ulubelu Unit 1 and 2 in Lampung Sumatra (Note: Supplying steam to PLN)
  • • 110 MW Ulubelu Unit 3 and 4 in Lampung Sumatra
  • • 55 MW Lumut Balai Unit 1 in South Sumatra
  • • 30 MW Karaha Bodas in West Java
  • • 12 MW Sibayak Unit 1 ,2 and 3 in North Sumatra

    Current Projects

  • • Constructing 55 MW Lumut Balai Unit 2 power station.
  • • Working on the infrastructure and drilling wells leading toward the construction of a 55 MW plant in the Sungai Penuh work area in Jambi, Sumatera.
  • Planning to build two 55 MW power stations in the Hululais work area in Bengkulu,Sumatra.


Star Energy Geothermal was established in 2003. Its vision is to be the fastest-growing, most profitable, best-managed energy company in the region. Star Energy, operating three geothermal power plants with a total installed capacity of 874 MW, is the largest geothermal energy producer in Indonesia.

Here are the three geothermal plants that it operates.

  • • Salak plant (337 MW) in West Java – Acquired from Chevron in 2017
  • • Darajat plant (270 MW) in West Java – Acquired from Chevron in 2017
  • • Wayang Windu (227 MW) in West Java – Acquired from Magma Nusantara Limited in 2004
  • Current Projects
  • • Exploring the geothermal prospect in Gunung Hamiding, located in North Maluku.
  • • Exploration in Sekincau in Lampung, Sumatera

    Here are the subsidiary companies of Star Energy Geothermal:
  • • Star Energy Geothermal Salak, Ltd.
  • • Star Energy Geothermal (Wayang Windu) Limited|
  • • Star Energy Geothermal Darajat II, Limited
  • • PT Star Energy Geothermal Suoh Sekincau


Geo Dipa Energy was established in 2002 by the government of Indonesia to build and operate the Dieng and Patuha geothermal plants. Managing two geothermal plants with a combined capacity of 125 MW, Geo Dipa Energy’s vision is to be a reliable and trusted geothermal company.

Here are the two plants that Geo Dipa Energy operates:

  • • 70 MW Dieng Unit 1 power plant located in Central Java.
  • • 55 MW Patuha Unit 1 power plant located in West Java.
  • Current Projects
  • • Dieng Unit 2 Development. Geodipa is currently drilling steam wells for the 55 MW Dieng Unit 2 power station project.
  • • Patuha Unit 2 Development.
  • • Exploration in the Candradimuka work area.
  • • Exploration in the Arjuno Welirang work area.


KS Orka Renewables, established in 2015, manages and operates four geothermal stations in North Sumatera and Flores.

Here are the power plants which KS Orka Renewables operates:

  • • 140 MW Sorik Marapi Unit 1, 2, and 3 power stations in North Sumatera
  • • 5 MW Sokoria geothermal plants in Flores.

Current Projects:

  • • Development of 50 MW Sorik Marapi Unit 4 station
  • • Exploration in the Samosir work area in North Sumatera

Here are the operating subsidiary companies of KS Orka Renewables:

  • • PT Sorik Marapi Geothermal Power
  • • PT Sokoria Geothermal Indonesia
  • • PT Samosir Geothermal Power


Supreme Energy was established in 2007 with a vision to become the leading and the most respected geothermal, generating clean and sustainable electricity. Supreme Energy operates three power stations in two work areas with a total installed capacity of 130 MW.

Here are the three power stations:

  • • The 45.6 MW Unit 1 and 45.6 MW Unit 2 stations in the Rantau Dedap work area in South Sumatera.
  • • The 85 MW Muara Laboh Unit 1 power plant in West Sumatera.
  • Current Projects
  • • Exploration in the Rajabasa work area
  • • Development of 75 MW Muara Laboh Unit 2 power station.

Here are the three subsidiary companies of Supreme Energy:

  • • PT Supreme Energy Rantau Dedap
  • • PT Supreme Energy Muara Laboh
  • • PT Supreme Energy Rajabasa


Sarulla Operations Limited is a consortium consisting of Medco Power Indonesia, INPEX, Ormat Technologies, Itochu Corporation, and Kyushu Electric Power. Sarulla Operations Limited was established in 2006 when PLN, the national power company of Indonesia, awarded the company to take over the development of the Sarulla geothermal project in North Sumatra.

The Sarulla geothermal resources, located in North Sumatra, were initially discovered by Unocal. Unocal conducted extensive exploration in the Sarulla geothermal working area from 1993 to 1998. It drilled a total of 13 deep wells and proved the existence of 330 MW of commercial geothermal reserves for 30 years.

However, due to the Asian financial crisis in 1997, Unocal did not get the approval to build the power plants. With a total investment of 1.7 billion USD, Sarulla Operation Limited completed the first power station in March 2017, the second station in October 2017, and the third station in March 2018.

Here are the three power stations that SOL operates :

  • • 110 MW Silangkitang (SIL) Unit 1
  • • 110 MW Namora-I-Langit (NIL) Unit 1
  • • 110 MW Namora-I-Langit (NIL) Unit 2


PLN Gas and Geothermal is a subsidiary company of Perusahaan Listrik Negara (PLN), the national power company of Indonesia. As the sole distributor of electricity in Indonesia, besides purchasing electricity from all independent geothermal operators, PLN also operates several geothermal power plants of its own.

Here are the geothermal plants which PLN operates:

  • • 110 MW Ulubelu Unit 1 and Unit 2 – Steam supplied by Pertamina Geothermal Energy
  • • Kamojang Unit 1 (30 MW), Unit 2 (55 MW), and Unit 3 (55 MW) – Steam supplied by Pertamina Geothermal Energy
  • • 10 MW Ulumbu Unit 1,2,3,4 in Flores
  • • 2.5 MW Mataloko in Flores

PLNGG has an ambitious plan to produce more geothermal power from its geothermal work areas. It is currently looking for international and national investors to partner and collaborate to develop the following four geothermal projects:

  • • 20 MW Tulehu in Central Maluku
  • • 10 MW Atadel in East Nusa Tenggara
  • • 10 MW Songa Wayaua in North Maluku
  • • 20 MW Tangkuban Perahu in West Java


As Indonesia is eager to increase its electricity generation using renewable resources, and with its abundant geothermal resources in its backyard, we shall see more geothermal development in the future.