The Energy Development Corp. (EDC), the renewable energy subsidiary of Lopez-led First Gen Corporation, is seeking approval for a major expansion of its 282.5-megawatt Southern Negros Geothermal Project (SNGP), proposing new wells, expanded steam field infrastructure, and a threefold increase in battery storage capacity as it works to sustain one of the country’s key sources of renewable baseload power.

The company has reportedly earmarked PHP 25 billion for the planned expansion.

Based on documents filed with the Department of Environment and Natural Resources (DENR), EDC is pursuing amendments to the project’s Environmental Compliance Certificate (ECC) to support a broad upgrade of the geothermal development in Valencia, Negros Oriental.

The proposal includes the drilling of eight new production and reinjection wells, construction of two additional well pads, expansion of steam-gathering pipelines and related facilities, installation of downhole heat exchanger and trickle injection technologies, and the development of a new transmission line.

EDC also plans to expand the project’s battery energy storage system (BESS) capacity to 90 megawatt-hours (MWh) from the existing 30 MWh, enhancing the facility’s ability to support grid operations and renewable energy integration.

According to the filing, the proposed changes are intended to optimize resource utilization, support future expansion, and accommodate evolving energy technologies.

SGNP currently supplies steam to EDC’s Palinpinon and Nasulo geothermal power plants and generates about 241.8 MW from its authorized 282.5-MW steam field capacity. Developed in the early 1980s, the geothermal field is among the country’s longest-operating renewable energy assets and remains a key source of baseload power for the Visayas grid.

The proposed upgrades would also expand its operational footprint to about 400 hectares from 151.5 hectares to accommodate the planned facilities. At the same time, EDC is seeking to refine the overall project boundary to 4,028 hectares from 5,163 hectares.

First Gen continues to position geothermal energy at the center of its renewable energy portfolio. In its 2025 Integrated Report, the company described geothermal as “a critical source of reliable, indigenous baseload power for the Philippines” and said it had invested approximately PHP 200 billion in geothermal development nationwide as of end-2025.

First Gen added that geothermal remains the foundation of its renewable energy platform. The company operates more than 1,300 MW of geothermal capacity across the country–over half of the country’s total output–making it the Philippines’ largest geothermal power producer.

If approved, the project would extend development activities at one of the Philippines’ longest-operating geothermal fields while adding storage capacity and new field infrastructure aimed at supporting long-term renewable energy production in the Visayas.

What role should geothermal and battery storage play in strengthening the Philippines’ energy security and renewable energy transition?

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