Utilization of waste heat
“For geothermal, there is also Co-Generation, added to the existing. There are already targets from 2027-2029 for COD,” said Minister of Energy and Mineral Resources (ESDM) Arifin Tasrif.
The business scheme that will be used for this project is a Joint Development Agreement (JDA) between PT PGE and PT PLN, signed a few months ago. The main focus of the JDA is the Ulubelu Bottoming Unit PLTP project which is planned to be developed with a capacity of 30 MW and the Lahendong Bottoming Unit PLTP with a development plan of 15 MW. Both projects are targeted to COD in 2027.
There are other potential sites for Co-Generation projects including Lumut Balai, Hululais, Kamojang, Sibayak, and Sungai Penuh. These projects expected to operate within the period 2027-2029.
Optimizing electricity dispatch
In addition, optimization of geothermal power plant (PLTP) is also carried out by prioritizing excess energy from currently operating PLTP. Excess energy from PLTP is prioritized to be dispatched into the PLN electricity system.
For PLTP operated by PT PGE, namely PLTP Kamojang, Ulubelu, Karaha, Lahendong, and Lumut Balai, there is a potential optimization of 1,081 GWh. This value is obtained from the remaining total net generation capacity of 5,528 GWh minus the distribution capacity to PT PLN of 4,447 GWh.
There is also plenty of potential optimization from other geothermal power plant operators – 134 GWh from PT Geo Dipa Energi (PLTP Dieng and Patuha), 365.8 GWh from PLTP Sorik Marapi and PLTP Sokoria, 494.8 GWh from Star Energy Group (PLTP Salak, PLTP Darajat, and PLTP Wayang Windu), and 24 GWh from Sarulla Operations (PLTP Sarulla).
In the North Sulawesi-Gorontalo (SulutGo) system, obstacles for PLTP optimization stem from the imbalance between the provision of electricity in the region and the demand growth, resulting in an over-capacity status. It is proposed to implement alternating shutdowns for fossil fuel plants while still considering the difference in generation prices from coal-fired power plants and geothermal power plants. It will also be necessary to expand the transmission and distribution network of PLN to maximize the use of geothermal energy in meeting the captive power of mining and industry in Sulawesi.
