Tiwi

The Tiwi field has an installed capacity of 275 MWe and is located about 300-km southeast of Manila in the Albay Province. Exploration began in 1964, and power was first generated in 1979. By 1982 Tiwi became the world’s first water-dominated geothermal system to produce more than 160 MWe. Philippine Geothermal, Inc. (PGI) operates the steam field and the National Power Corporation (NPC) constructed and operates the power plants.

The Tiwi geothermal field is located on the northeast flank of Mt. Malinao, an extinct Quaternary stratovolcano in the East Philippine Volcanic Arc. This arc is a belt of upper –Miocene to Recent calc-alkaline volcanoes associated with subduction along the Philippine Trench. Mt. Malinao is composed dominantly of <0.5 million year-old andesitic lavas and lesser pyroclastic rocks.