The Lahendong geothermal power plant project, operated by a subsidiary of State-owned energy company Pertamina, PT Pertamina Geothermal Energy, has emerged as the most traded carbon unit on Indonesia’s Carbon Exchange, IDXCarbon, according to the Indonesia Stock Exchange (IDX).

IDX Director of Development Jeffrey Hendrik said that seven carbon units are currently being traded on the Indonesian Carbon Exchange.

“Of the 1.59 million tons of CO₂equivalent traded, 56 percent − or about 899,000 tons − came from Pertamina’s Lahendong project,” Jeffrey saidduring the “Carbon Business Upscaling Strategy: Optimizing Domestic and International Market Opportunities” seminar held on Monday, April 28, 2025.

He noted that the remaining carbon reduction certificates (SPE) being traded originated from several projects owned by State power utility PT PLN. The second most traded project was the Sumbagut 2 gas engine power plant (PLTMG), accounting for 21.74 percent or 347,557 tons.

Third place went to the Muara Karang Block 3 combined-cycle gas power plant (PLTGU), which contributed 283,112 tons, or 17.71 percent. This was followed by the Priok Block 4 PLTGU with 38,117 tons, representing 2.38 percent.

Fifth on the list was PLN NP UP Muara Tawar’s project converting a single-cycle plant to combined-cycle in Block 2, with 30,005 tons or 1.88 percent.

The sixth and seventh positions were occupied by the Gunung Wugul mini hydro power plant (PLTM) with 694 tons or 0.04 percent, and the Grati Block 2 PLTGU with 317 tons or 0.02 percent, respectively.

Ignatius Denny Wicaksono, Head of Business Development Division 2 at IDX, revealed that all carbon units sold originated from the seven registered projects.

“Right now, we have seven projects with a total volume of about 3 million tons, of which 900,000 tons have already been retired,” Denny said.

He reported that these trades have generated a total transaction value of Rp78 billion (US$5 million) as of April 2025. With the current project volume, the total carbon available for trading has reached 2.2 million tons.

The platform has seen a surge in users, with a total of 112 institutional participants from both domestic and international markets, a significant increase from just 16 at the exchange’s initial launch.

“There are 112 registered participants, but actual users have reached around 1,176. So it turns out many individuals are using the carbon market to offset their emissions,” he said.