Geothermal power plants are becoming a vital part of the clean energy transition across Asia. Drawn from the natural heat within the Earth, geothermal energy provides a stable source of electricity that operates day and night, regardless of weather conditions. Geothermal energy stands out not only for its consistency but also for its potential to strengthen energy security and drive long-term sustainability in countries like the Philippines and Indonesia.
As nations chart pathways toward decarbonization, geothermal energy continues to play a central role in meeting climate goals and expanding renewable energy capacity. The presence of different types of geothermal power plants across volcanic and tectonically active regions offers a unique opportunity to harness clean, firm power at scale.
What are geothermal power plants?
Geothermal power plants convert the Earth’s internal heat into electricity. The heat comes from naturally occurring reservoirs deep underground, where water and steam are heated by molten rock. A geothermal facility taps into that reservoir, channels the steam or hot fluid to a turbine, and produces electricity.
Because the heat source is consistent, geothermal plants can deliver baseload power year-round, unlike solar or wind. This translates into long-term asset stability and predictable cash flow for investors. For regulators and governments, geothermal energy supports grid reliability and decarbonization goals. And for communities, these plants bring job opportunities, infrastructure improvements, and energy security when responsibly developed.
Geothermal power plants typically operate at high capacity factors—often between 70 and 90 percent—because they are not dependent on sunlight or wind. This reliability also makes geothermal energy a crucial complement to other renewables.
How do geothermal power plants work?
While geothermal technologies vary by geological conditions, ACEN’s investments leverage the systems best suited to each site. These technologies enable geothermal energy to be deployed across a range of temperatures and terrains, making it adaptable to diverse landscapes.
Key strategies include:
- Reservoir reinjection, which helps maintain the long-term sustainability of geothermal fields
- Continuous monitoring of pressure, chemistry, and microseismic activity, ensuring responsible operations
- Adoption of international environmental standards, reinforcing ACEN’s sustainability commitments
These innovations enable ACEN to operate geothermal power plants efficiently while minimizing environmental impact and maximizing power output. By combining geothermal with other renewables, ACEN is building a resilient, flexible energy system capable of powering economic development across the Asia Pacific.
Key geothermal assets in ACEN’s portfolio
As the first energy company in Southeast Asia to establish a Net Zero roadmap, ACEN is guiding the development of sustainable energy platforms that meet both present and future demand. Geothermal assets, with their long-term stability and low emissions, align directly with this roadmap and support energy security across multiple markets.
Through joint ventures and long-term partnerships, ACEN is investing in geothermal projects that support inclusive growth, community development, and environmental stewardship, positioning the company as a key driver of firm renewables in the region.
These projects demonstrate how homegrown renewable energy projects in the Philippines and Indonesia can fuel progress while protecting the environment.
Maibarara Geothermal (Philippines)
The 32 MW Maibarara Geothermal represents one of the Philippines’ geothermal power plants. Located in Sto. Tomas, Batangas, the facility delivers dependable energy that remains virtually unaffected by seasonal weather conditions. Phase 1 was commissioned in 2014, marked a milestone as the first renewable energy project under the Philippines’ Renewable Energy Act of 2008, while its Phase 2 went online in 2018, and reinforced the plant’s role in supporting local and regional energy needs.
Salak and Darajat Geothermal Plants (Indonesia)
ACEN’s investment in the 712 MW Salak and Darajat Geothermal plants in West Java, Indonesia, reflects the company’s ambition to build a geographically diversified portfolio of firm renewable assets. These geothermal power plants are operating within one of the most resource-rich geothermal regions globally.
The investment expands ACEN’s offshore presence and strengthens its ability to deliver round-the-clock renewable energy across borders. Long-term power purchase agreements and proven geothermal reservoirs make Salak and Darajat valuable assets that complement ACEN’s solar, wind, and storage capacity across the Asia Pacific.
dditionally, wind power creates local jobs in manufacturing, installation, and maintenance, boosting rural economies. Its lower operational costs and renewable nature contribute to long-term energy price stability and environmental benefits that help combat climate change, making wind energy a cost-effective and responsible energy choice for communities and investors alike.
Powering the future with geothermal energy
Geothermal energy is one of the most reliable and sustainable sources of renewable power available today. Understanding what geothermal power plants are helps investors, regulators, and communities see their potential to drive long-term progress.
For ACEN, geothermal energy is about creating a future that’s clean, stable and inclusive. Through strategic investments in geothermal facilities like Maibarara and Salak & Darajat, ACEN demonstrates its commitment to delivering firm renewable energy solutions that support national and regional energy goals.
Aside from solar and wind, geothermal power reinforces the company’s role in driving resilient, low-carbon growth across the Asia Pacific. The integration of geothermal energy into ACEN’s portfolio underscores its importance for a future built on stability, innovation, and sustainable progress.
Learn more about ACEN’s growing portfolio as a geothermal energy company.
References:
- U.S. Energy Information Administration. (2022, December 21). Geothermal power plants. https://www.eia.gov/energyexplained/geothermal/geothermal-power-plants.php
- J.M.K.C. Donev et al. (2024). Energy Education. Geothermal power plants. https://energyeducation.ca/encyclopedia/Geothermal_power_plants
- Eurelectric. (2024, August 30). What is geothermal power? https://www.eurelectric.org/in-detail/what-is-geothermal-power/
