ACEN Corporation has announced plans to invest approximately PHP15.8 billion (USD268 million) to develop a 2 GWh battery energy storage system (BESS) at its San Marcelino solar park in Zambales, Philippines. The project aims to enhance the reliability and flexibility of renewable energy supply by integrating large-scale storage with solar generation.
The San Marcelino solar park has a total planned capacity of 585 MW and is being developed in multiple phases. The first two phases, with a combined capacity of 384 MW, are already operational and supplying electricity to the grid. A third phase, adding 200 MW of solar capacity is currently under construction and is expected to begin commercial operations by the third quarter of 2027.
The battery storage system will store surplus electricity generated during peak sunlight hours and release it during periods of lower solar generation or higher electricity demand. This will help stabilise power supply and improve grid reliability as renewable energy capacity expands. Construction of the BESS facility is expected to begin in the third quarter of 2026, with completion targeted by the end of 2027 and commissioning planned for early 2028.
The investment forms part of ACEN’s broader renewable energy expansion strategy. The company has allocated around PHP80 billion in capital expenditure for 2026 to support new renewable energy projects and infrastructure. ACEN is targeting an operational renewable energy capacity of 5 GW by the end of 2026 and currently manages a renewable energy portfolio of about 7 GW across various stages of development in the Asia-Pacific region.