The Philippines is the world’s second largest producer of geothermal energy for power generation. In fact, it is home to three of the top ten biggest geothermal power plants in the world. Makban Geothermal Complex in Batangas Provinces producing 458 MW output capacity, Tiwi Geothermal Complex with a net capacity of 289 MW in the province of Albay and Maltibog Geothermal Power Station in Leyte island with 232.5 MW capacity in Leyte Province. The Philippines is located within the Pacific Ring of Fire. This implies that, it is prone to intense volcanic activity and earthquakes. There are 53 active volcanos in the Philippines.

Figure 1: Active Volcanos, Philippines. SOURCE: Volcano Discovery

Nevertheless, this strategic position has given it great thermal resources which have been exploited since 1977.  Most of the geothermal systems that have the potential for exploitation are found in mature volcanic complexes. The first geothermal power plant was established in Leyte. Philippine geothermal resources are spread among 7 specific regions: Leyte, MakBan, Tiwi, South Negros, BacMan, Mindanao, and the Northern Negros. At 1902.32 MWe, around 50% of discovered resources are exploited, Fronda et al, 2010. The Philippines probably has up to 2511 MWe of unexploited geothermal power, Aloysius Makalinao, 2016.

Figure 2:  Geothermal Service Contracts. Source: DOE

In 2008, the Congress in the Philippines enacted Republic Act No. 9513 that promotes the development, utilization and commercialization of the renewable energy resources. It is in the same act where geothermal energy resources were defined as renewable mineral resources that have to be harnessed by geothermal energy systems. This enactment coupled with the trends in renewable energy have increased geothermal activity within the country.

Most geothermal fields drilled in the Philippines have liquid temperatures ranging between 300-340 degrees Celsius. Two or three exploratory wells are drilled to depth 2500-3000 meters based on the abstract model of the reservoir with consideration of the environment to maximize the information obtained downhole. Ideal structures have good permeability and high temperatures.

Geothermal exploration and development are currently done by the private sector with the little to no help by the government. This is as a result of the government’s decision to privatize the power generation. The government plays its role through the Department of Energy (DOE) which negotiates Geothermal Service Contracts (in accordance with P.D 1442, or the Geothermal Service Contract Law of the Philippines).

Figure 3: Geothermal Area for Offer. Source: DOE

In 2019, the DOE has announced the following areas for bidding:

• Acupan-Itogon Geothermal Prospect with a 10-20 MWe geothermal resource potential covering approximately 3.5 KM² and a confirmed secondary permeability reservoir temperature of 229-236^o
• Southern Leyte Geothermal Prospect covering 7.5-12 KM² with bottom hole temperature of 280^oC with a potential to produce 26-34 MWe.
• Amacan Geothermal Prospect with a resource potential of 20-40 MWe with 365^oC confirmed downhole temperature.
• Balut Island Geothermal Prospect, low enthalpy (estimated 200^o C downhole temperature) with a vastness of 4-9 KM² and 10-40 MWe geothermal potential.

Figure 3: Geothermal DATA. Source: Geothermal Development in the Philippines: The Country Update

This wraps up our #GeothermalCountryOverview for The Philippines.  For more #GeothermalFactsandStats check back weekly for new content and scroll through our previous posts!  Check us out on Linkedin, Facebook, Twitter and Instagram as well.

Guest Author: George Yabesh (LinkedIn Profile)

REFERENCES

• Fronda, M. Marasigan, and V. Lazaro, “Geothermal Development in the Philippines: The Country Update,” Department of Energy of the Philippines, 19 April 2015.
• Aloysius Makalinao,” Philippines Geothermal Future,” Stanford University, Fall 2016.
• Francis M. Dolor, “Phases of Geothermal Development in the Philippines,” 2005.
• https://www.doe.gov.ph
• https://www.power-technology.com/features/feature-top-10-biggest-geothermal-power-plants-in-the-world/

Want to learn more? Check out our Intro Post to a 6-part blog series on Geothermal Mapping!