The Sarulla Geothermal Power Plant in Indonesia


The Sarulla power plant with a total capacity of 330 MW is the largest geothermal power plant in Indonesia and also one of the 10 largest geothermal power plants in the world.

The Sarulla power plant has three combined cycle units. Construction of the power plant started in May 2014 and the first unit named Silangkitang was completed in March 2017. Units Namora I-Langit 1 and Namora I-Langit 2 started operation in October 2017 and May 2018 respectively.

Located in North Sumatera of Indonesia, the power plant is operated by Sarulla Operations Ltd, a consortium consisting of Medco Energi, Itochu, Kyushu Electric Power Company, Inpex and Ormat with a total investment of US $1.7 billion.

The generated electricity is distributed by PLN, Perusahaan Listrik Negara, which is the state-owned electricity company of Indonesia.

This project demonstrates the commitment of the Indonesian government to increase energy production from renewable resources, especially from its huge geothermal potential. Indonesia has 40% of the world’s geothermal resources. The Indonesia government said three new geothermal power plants will start to operate this year. They are the 55 MW PLTP Lumut Balai, 40 MW PLTP Sorik Marapi and the 5 MW PLTP Sokoria.

The total installed geothermal power in the world in 2018 is 14,600 MW according to ThinkGeoEnergy. The five countries producing more than one Giga Watt (GW) of geothermal power are:

  1. The USA – 3639 MW
  2. Indonesia – 1948 MW
  3. The Philippines – 1868 MW
  4. Turkey – 1347 MW
  5. New Zealand – 1005 MW

Here is a little bit of interesting history about the Sarulla project. The Sarulla geothermal resource was originally explored and discovered by Unocal North Sumatera Geothermal. Unocal’s plan to construct the first power plant was suspended during the financial crisis in 1998.



Geothermal Plants near a Volcano

Geothermal plants can be safely situated near a volcano, says Dr. Roland Horne, Thomas Davies Barrow Professor in the School of Earth Sciences and Senior Fellow at the Precourt Institute for Energy at Standord University.

You can read the outstanding article from Stanford University titled Geothermal at the foot of Kilauea on this and on the recent volcano eruption of Mt. Kilauea in Hawaii at

In this article, Dr. Roland Horne discusses geothermal energy in the face of natural hazards and a way to tap the earth’s heat far from volcanoes in the future.

I highly recommend you read the article that I mention above. In this article you can also watch the awesome lava flow from a fissure of Mt. Kilauea on May 19, 2018 and learn about Stanford University’s School of Earth, Energy & Environmental Sciences.