Mitsubishi Power’s Geothermal Plant Retrofit Increases Output, Reduces Emissions

Star Energy Geothermal Darajat II (SEG) awarded Mitsubishi Power a retrofit contract for Unit 3 at its Darajat Geothermal Power Plant in Indonesia. The retrofit, scheduled to conclude in fall 2026, will upgrade the plant’s steam turbine and associated equipment. Upon completion, the plant’s power output will increase from 121 MW to 129 MW.

Integrating a highly efficient and reliable steam turbine will also:

• establish a stable electricity supply
• reduce related CO₂ emissions
• deliver an increased renewable energy ratio for Indonesia

"Indonesia has the second-largest geothermal power generation capacity in the world,” said Kazuhiro Yoshida, President of Mitsubishi Power Indonesia. “We have provided a total of six units for geothermal power plants in the country, with total output amounting to approximately 400 MW. In addition, we are currently involved in the construction of an additional unit. Through geothermal power generation and other clean energy technologies, Mitsubishi Heavy Industries will contribute to achieving the Indonesian government's goal of carbon neutrality by 2060."

The Plant and Additional Work

SEG’s geothermal plant is sited in Garut, West Java, approximately 200 km southeast of Indonesia’s capital—Jakarta. Previously, Mitsubishi Power delivered a steam turbine to the plant in 2007. Mitsubishi Heavy Industries’ Nagasaki Shipyard & Machinery Works will handle project design, manufacturing, and installation support, while Mitsubishi Power Indonesia will conduct maintenance to ensure long-term stable operation.

"Amid rising electricity demand in Indonesia, there is also greater pressure from consumers for electricity derived from renewable energy,” said Hendra Soetjipto Tan, CEO of BREN and SEG. “Through this project, we will contribute to both Indonesia's economic development and cleaner energy."

Mitsubishi Power – Power Generation

In mid-October, Mitsubishi Power finished construction for a 50-MW-class woody biomass-fired power plant in Hyuga, within Japan’s Miyazaki Prefecture, and handed over the facility within the contract period. The Hyuga Biomass Power Plant, developed by an MHI consortium as part of a turnkey solution for engineering, procurement, and construction (EPC), will be operated by a special purpose company—Hyuga Biomass Power Co. Hyuga Biomass Power is jointly owned by Osaka Gas Co., ITOCHU Corp., Tokyo Century Corp., and Tokyo Energy & Systems Inc.

The power plant facility contains a steam turbine, circulating fluidized bed (CFB) boiler, generator, and additional equipment that offers high combustion efficiency for biomass power generation. Increased power generation and fuel efficiency will reduce the plant’s environmental impact. As part of its EPC contract, MHI built and supplied main power generating equipment, including the steam turbines, CFB boiler, and other large auxiliary machinery.

Also in October, Mitsubishi Power completed construction on the eighth and final M701 JAC unit for a 5,300 MW natural gas-fired power plant project in Thailand. The project is a joint venture between Gulf Energy Development Public Co. and Mitsui & Co., and successfully began full commercial operations on October 1, 2024. This milestone marks the on-time completion of a multi-phase project awarded in 2018, featuring two plants in the Chonburi and Rayong provinces. Each plant is equipped with four M701 JAC gas turbines, steam turbines, and heat recovery steam generators.