The USD $1.6 billion Sarulla geothermal plant, which will have a total capacity of 330 MW once it its third unit comes online in 2018, is known as the world's largest single-contract geothermal power project. It sells its electricity to state-owned utility company Perusahaan Listrik Negara (PLN) over a 30-year period).

It is no coincidence that this plant is being developed in Indonesia because Southeast Asia's largest economy is estimated to contain roughly 40 percent of the world's total geothermal reserves (with Indonesia's total capacity estimated at 28,994 MW). However, the nation only utilizes about 7 percent of its geothermal energy capacity.

Geothermal energy should be exploited by Indonesia to overcome the nation's power deficit. Indonesia's total installed capacity of geothermal power is currently around 1,500 MW while an additional 750 MW is being constructed. However, within a decade the government targets to raise the country's installed capacity to 7,200 MW of geothermal power. To achieve this target much more geothermal power development is required. Moreover, by 2025 the government wants renewable energy, including geothermal, to account for 23 percent of the nation's energy mix.

Japan's Inpex Corporation holds a 18.25 percent stake in the Sarulla geothermal plant. Meanwhile, Japan's Itochu Corporation and Kyushu Electric Power, hold a 25 percent stake, each, while US-based Ormat Technologies commands a 12.75 percent stake in the project. The remaining 19 percent are controlled by Medco Power Indonesia (a subsidiary of Medco Energi Internasional).

In terms of actual geothermal power production, Indonesia currently ranks third after the United States (3,450 MW) and the Philippines (1,870 MW). Indonesia produced 1,698 MW of geothermal power per June 2017 (but this figure will rise now the second unit of the Sarulla plant came online). Hence Indonesia may become the world's second-largest geothermal power producer before the end of 2017 (with a targeted total capacity of 1,908 MW).