Geothermal operators in Indonesia are experiencing a busy year in 2025. The second half of the year is marked by a range of activities, including the arrival of two new players in the country’s geothermal sector: EDC from the Philippines and PT DSSR Daya Mas Sakti from Indonesia.
Pertamina Geothermal Energy (PGE)
Pertamina Geothermal Energy began operating its newest facility, the 55-MW Lumut Balai Unit 2 power plant, on June 29, 2025. This addition raises PGE’s total installed geothermal capacity to 727.5 MW.
The company has set a goal to reach 1 GW within the next three years, which will be achieved through the completion of several projects: the Hululais power plant Units 1 and 2, contributing a combined 110 MW, and multiple cogeneration projects totaling 230 MW. Additionally, PGE plans to start exploration activities in the Gunung Tiga area in Lampung, which has an estimated potential of 55 MW.
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Pertamina Geothermal Energy (PGE) plans to invest USD 24 million in PGE Kotamobagu to advance the development of the Kotamobagu geothermal site in Sulawesi.
PGE Kotamobagu is a joint venture between Pertamina Geothermal Energi, Chevron New Energies, and Mubadala Energy, overseeing a work area with an estimated potential capacity of 280 MW.
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PGE’s Ulubelu Geothermal Complex has been selected as a national case study for the Water-Energy-Food (WEF) Nexus initiative. This program aims to assess the effects of geothermal development on water and food resources, as well as its broader impact on local communities.
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Additionally, PGE has broken ground on the Green Hydrogen Pilot Plant in Ulubelu, Lampung. Scheduled to begin operations in 2026, the facility will produce green hydrogen using electricity supplied from the Ulubelu geothermal power plant.
Star Energy Geothermal
Star Energy Geothermal has completed a retrofit project for Units 4, 5, and 6 of the Salak geothermal power plant in West Java.
The upgrade increased the field’s installed capacity by 7.7 MW, exceeding the expected 7.2 MW, bringing the total installed capacity to 910.3 MW.
The company invested USD 22.5 million in the retrofit and plans to add over 100 MW of new geothermal generation capacity in the coming years, with a total investment target of USD 365 million.
Outside Java, Star Energy has commenced drilling its first exploration well at the Hamiding geothermal work area in North Maluku. The Hamiding project is initially targeting a capacity of 50 MW, with the potential to reach a total capacity of 300 MW.
Geo Dipa Energi
Geo Dipa Energi is expanding installed capacities at both the Dieng and Patuha geothermal fields with financial support from the Asian Development Bank.
Earlier this year, the company completed the well testing phase for 18 wells across the two projects. Commercial operations for Dieng Unit 2 and Patuha Unit 2 are expected to begin in 2027.
Geo Dipa recently signed an agreement with the Dutch consultancy Witteveen+Bos to conduct a lithium extraction pilot project from geothermal brine at the Dieng site. Funded by the Dutch government, the project aims to assess the feasibility of lithium recovery, with estimates suggesting the Dieng field could produce up to 2,200 tons of lithium per year, equivalent to approximately 3.5 GWh of battery capacity.
Supreme Energy
Supreme Energy Muara Laboh (SEML)—a joint venture between Supreme Energy, Sumitomo Corporation, and Inpex—is investing USD 490 million to expand its Muara Laboh geothermal facility in West Sumatra. The expansion includes the construction of the 80 MW Muara Laboh Unit 2 plant, scheduled for completion in 2027. When completed, the Muara Laboh geothermal power plant will have a total capacity of 165 MW.
To support the new unit, SEML has launched a drilling campaign involving six to eight production and injection wells.
EDC and PT DSSR Daya Mas Sakti
First Gen Corporation, through its renewable energy arm Energy Development Corporation (EDC), has announced plans to invest USD 80 million to establish a presence in Indonesia’s geothermal sector in partnership with PT DSSR Daya Mas Sakti, a subsidiary of the Sinar Mas Group.
The collaboration covers multiple geothermal prospects across West Java, West Sumatra, Jambi, Central Sulawesi, and Flores, with a combined target capacity of around 440 MW.
This marks EDC’s first overseas geothermal venture and Sinar Mas Group’s first geothermal project.
Medco Power Indonesia
Medco Power Indonesia, through its subsidiary Medco Geothermal Sumatera, has commenced exploration drilling at the Bonjol geothermal site in West Sumatra.
The company plans to drill two wells, Bonjol-1 and Bonjol-3, with completion expected by the end of 2025.
The Bonjol resource, classified as medium-enthalpy, has an estimated capacity of 60 MW and a fluid temperature of approximately 150°C.
PLN (Perusahaan Listrik Negara)
Indonesia’s state electricity company PLN has begun infrastructure development for geothermal drilling at the Mataloko work area site in East Nusa Tenggara.
Current activities include constructing well pads, access roads, and drilling support infrastructure, which is now approximately 80% complete.
Drilling is expected to begin in 2026, with a development target of 2×10 MW for the site.
PT Sarana Multi Infrastruktur (SMI) and Ormat Geothermal
Sarana Multi Infrastruktur (SMI) and Ormat Geothermal Indonesia have signed a cooperation agreement to explore financing options for geothermal exploration in Wapsalit in Maluku and Toka Tindung in North Sulawesi.
SMI, as a Special Mission Vehicle under Indonesia’s Ministry of Finance, supports energy and infrastructure financing and has previously been involved in the 10-MW small-scale geothermal project at Dieng operated by Geo Dipa Energi.
Ministry of Energy and Mineral Resources of Indonesia
The Government of Indonesia, through the Ministry of Energy and Mineral Resources (ESDM), continues to enhance the policy framework to accelerate geothermal development.
Starting this year, Geothermal Work Area (WKP) auctions will be conducted through the Geothermal Energy Information System (GENESIS)—a digital platform designed to streamline geothermal management.
This initiative aims to simplify permitting processes, reducing the average permit processing time from 18 months to just 5 days.
This article is adapted from ThinkGeoEnergy articles.
Jamin Djuang
