Meralco PowerGen Corp. (MGEN) is accelerating its diversified energy strategy, recently energizing the first phase of what is now the largest operational battery storage system in the country.

The company announced Thursday that its affiliate, Terra Solar Philippines Inc., began contributing 250 megawatts of solar capacity to the national grid in March.

Alongside the solar launch, the firm energized the first tranche of its battery energy storage system (BESS), which can deliver up to 450 megawatt-hours of electricity during nighttime hours.

MGEN president and CEO Emmanuel V. Rubio said the company’s priority is to ensure a reliable and secure power supply as the Philippine government reassesses its energy mix in response to global fuel market volatility.

“Our priority is to help ensure a reliable and secure power supply while supporting the country’s evolving energy mix,” Rubio said. “As more renewable energy comes into the system, maintaining adequate and dependable capacity remains essential.”

The company’s renewable arm currently maintains over 400 megawatts of capacity across seven solar sites in Luzon, including Bulacan, Ilocos Norte, and Batangas. MGEN is also investing in natural gas through LNGPH and PacificLight Power in Singapore as part of its transition to lower-carbon technologies.

Despite the push for renewables, MGEN continues to invest in baseload thermal capacity to support grid stability. In the Visayas, its facilities in Panay and Cebu provide more than half of Cebu Island's power requirements.

Future projects include the development of a 1,200-megawatt ultra-supercritical coal-fired power plant in Atimonan, Quezon. The facility, which will use high-efficiency, low-emissions (HELE) technology, is expected to be operational by 2030 and provide about 7% of Luzon’s total electricity demand.

MGEN is also targeting the completion of the first phase of its Toledo BESS in Cebu later this year.

Rubio stressed that the company is building a portfolio that works as a coordinated system rather than managing technologies in isolation. This integrated approach is intended to meet a projected surge in domestic electricity demand through 2040 while managing the variability of renewable sources.