Indonesia's Mount Ungaran Geothermal Project Faces Local Water Concerns

Local water fears could delay Indonesia's geothermal expansion at Mount Ungaran, risking agricultural access for communities in Central Java.

Indonesia's state-owned utility PLN has been permitted to explore Mount Ungaran for geothermal energy in Central Java province, targeting commercial electricity by 2031. The project—currently in exploration phase—requires drilling up to 2,200 meters deep, with drilling expected to begin late 2028 or early 2029. Local residents in Bawen subdistrict express concerns that development could reduce water availability for farming, pollute sources, increase earthquake risks, and expose them to toxic gases. The site also contains 1,300-year-old Hindu temples, adding cultural complexity.

The project’s scale matters: Indonesia’s estimated geothermal potential is 23.2 gigawatts, with current installed capacity at 2.78 gigawatts as of August 2026. Ungaran alone holds 55 megawatts of potential—enough to power 100,000 homes if developed. Yet the exploration phase must confirm resource viability before construction, a hurdle that could delay clean energy access for communities reliant on local water.

This friction directly impacts sustenance security for residents who depend on agriculture. If water access is compromised, it could worsen food insecurity for thousands in a region where geothermal expansion is part of Indonesia’s push for clean energy. The project’s success hinges on resolving community concerns before drilling begins, as historical disputes over similar projects in Central Java show.

What to watch: Permitting timelines, cultural heritage protections, and whether community dialogue (facilitated by Central Java’s provincial government) resolves water fears before drilling commences. The source notes all potential figures are Ministry estimates, and community concerns reflect resident statements—not verified technical assessments.

Source: Mongabay