One worker has died and at least 10 others injured after inhaling toxic gases at Geo Dipa Energi’s (GDE) Dieng geothermal project in Central Java, Indonesia.

State-owned geothermal company GDE, which operates the plant, said the gas leaked while employees were checking a relief valve in preparation for drilling on well pad number 28.

“One person was killed, and five others are in intensive care at the Wonosobo Hospital after the incident. Geo Dipa management and staff express our deepest condolences for the accident. Geo Dipa will also be responsible for all the victims,” GDE corporate secretary Endang Iswandini was quoted by the Jakarta Post.

“The cause will be determined by an investigation led by the [Ministry of Energy and Mineral Resources’] renewables inspector. Initial information shows that the cause was equipment malfunction,” she said.

Endang stressed that there was no blowout during the drilling of a well but that a release of toxic gas when a worker checked a relief valve on a mud pump. He added that all standard safety procedures were being implemented at the time of the incident.

Activists are now urging regulators to better enforce workplace safety practices at geothermal power plants after the suspected hydrogen sulphide leak at the project killed and injured employees on Saturday.

Environmental group Mining Advocacy Network (Jatam) activist Ki Bagus Hadi Kusuma called on the government to stop all geothermal projects across Indonesia, evaluate existing and planned geothermal working areas (WKP) and form an independent team consisting of the National Commission on Human Rights, experts and civil society groups to investigate accidents at the projects.

Indonesia has more than 60 geothermal working areas. Rich in geothermal resources, the republic is targeting a total of 3.35 gigawatts of geothermal power production capacity by 2030, according to its long-term electricity procurement plan.

Jacobs to help boost production capacity

US engineering services company Jacobs in February was appointed by GDE as subsurface project management consultant for the planned expansion of its Dieng and Patuha geothermal power plants in Java.

The project will increase the power generation output of the Dieng and Patuha geothermal fields from 110 megawatts to 220 MW and help expand renewable power generation in support of Indonesia's transition toward a cleaner energy future.

Jacobs will carry out a geoscientific study of the geothermal resource, including a review of the conceptual reservoir model and development strategy, well targeting, geological prognosis and well programming, together with developing the drilling strategy and drilling risk mitigation.

The contractor will also provide technical knowledge on geothermal resource utilisation and build on the lessons learned from prior drilling campaigns at Dieng and Patuha.

"Jacobs has a proven history in successfully delivering geothermal development projects in Indonesia as well as across the globe over the last 40 years," said Jacobs general manager Keith Lawson.

"This project is a great opportunity for us to continue to support GDE in harnessing Indonesia's geothermal resources to meet a cleaner, more sustainable, and efficient energy future and help attract additional investment in the geothermal sector in Indonesia."

The power plants are the first geothermal projects that are being financed by the Asian Development Bank under a direct lending scheme.

The project will provide job opportunities to the local communities, renewable electricity to the Java-Bali network, and reduce carbon emissions by more than 700,000 tonnes annually as compared to power generation from fossil fuels.

"This is a strategic project that can help meet the people's need for clean energy. It will have a positive impact on the social and economic aspects, especially for the surrounding areas," said GDE president director Riki Firmandha Ibrahim.

"This is a good opportunity for Jacobs to play a big role in driving positive changes in Indonesia."