The 1,600MW Muara Karang power plant located in Pluit, approximately 10km north-east of Jakarta, Indonesia, is being expanded to add a 500MW gas turbine combined-cycle (GTCC) power generation unit.

The  Muara Karang combined-cycle power plant  is owned and operated  by PT Pembangkitan Jawa Bali (PJB), a subsidiary of PT Perusahaan Listrik Negara (PLN), which is the state-owned electricity generation and distribution utility of Indonesia.

The engineering, procurement, and construction (EPC) contract for the Muara Karang expansion was awarded in September 2016, while civil construction works were started in August 2018.

Scheduled to commence commercial operations in October 2020, the new plant will help meet the growing electricity demand in the capital region of Indonesia, while reducing greenhouse gas emissions. The project is expected to have 25 years of operational life.

Muara Karang expansion project background

The  Muara Karang energy facility was originally  built in 1979 as a coal-fired power station in the northern suburbs of Jakarta.

It was converted into a natural gas-based combined-cycle operation with the installation of three GE gas turbines in 1992 and two M701F gas turbines from Mitsubishi Hitachi Power Systems (MPHS) in 2011.

The power generated by  the plant is evacuated to the 150kV grid network that powers some of Jakarta’s major business districts and government establishments.

Muara Karang expansion is one of the expansion projects being carried out at big thermal power plants in West Java, as part of the Government of Indonesia’s National Energy Policy of 2014 to increase the country’s generation capacity from 51GW to 115GW by 2025.

Plant make-up

The Muara Karang expansion will comprise a 500MW combined-cycle generating unit equipped with a M701F gas turbine as well as a steam turbine from Mitsubishi Hitachi Power Systems (MPHS).

The high-temperature flue gases released from the gas turbine will be fed to the steam turbine for additional power generation. The start-up time of the plant will be 45 minutes, while the overall combined-cycle efficiency is expected to be more than 62%.

Weighing approximately 415t, the gas turbine was fabricated at MHPS' Takasago Works in Hyogo Prefecture, Japan, and shipped to the plant location in June 2019.

Transmission infrastructure

The power generated by the plant will be evacuated to the national grid through a 500kV extra-high-voltage (EHV) looping transmission line connecting several power plants in the north Jakarta region.

The EHV line will connect the Duri Kosambi, Muara Karang, Priok, and Muara Tawar power stations to improve power supply in Bekasi and Jakarta.

The new plant will use the existing switchyard and substation infrastructure at the Muara Karang site.


PT PLN secured 70% of the expansion project cost from the Japan Bank for International Cooperation (JBIC) in April 2017. The remaining 30% of the project cost comes from PLN’s internal funds.

Contractors involved

Mitsubishi Hitachi Power Systems (MPHS), in consortium with Indonesia’s leading civil construction firm Wijaya Karya (WIKA), was awarded a full-turnkey EPC contract worth IDR3.9bn ($293m) for the Muara Karang expansion in September 2016.

MHPS is the supplier of main equipment including the gas and steam turbines and generators as well as auxiliary equipment for the new plant.

WKA is responsible for the civil construction and installation works of the project.

A long-term service agreement was also signed with MPHS for providing long-term maintenance and management support including remote monitoring services, and for  assigning a site service director for the new plant.