The first phase of the MTerra Solar development in the Philippines has successfully achieved initial grid synchronisation and energisation to the Luzon grid, marking a major milestone for what is set to become the world’s largest integrated solar-plus-storage project.

Developed by Meralco PowerGen Corporation (MGEN), the project is being constructed on the island of Luzon and will ultimately deliver a planned 3.5 GW of solar PV capacity paired with 4.5 GWh of battery energy storage (BESS). Once fully completed, MTerra Solar is expected to be the largest solar-plus-storage facility globally.

Phase One: Rapid Deployment

Phase one covers approximately:

• 2.5 GW of solar PV
• 3.3 GWh of battery energy storage

As of the end of January:

• 1,288 MW of solar PV had already been installed
• 622 BESS units were deployed

This makes MTerra Solar already the largest installed PV array in the Philippines, even before full phase-one completion.

The project’s initial switch-on to the Luzon grid confirms system readiness and safe connection. According to MGEN, the plant is targeting operational readiness of:

• 250 MWac of solar capacity
• 112.5 MWh of BESS capacity
• Export of 85 MW of constant power to the grid by the end of this month

These early exports will provide firm and dependable capacity, combining daytime solar generation with battery-backed stability, a first of this scale in the country.

Transmission Infrastructure & Grid Integration

A key element of the milestone was the energisation and cut-in of a 500 kV substation along the Nagsaag–San Jose 500 kV Line 2. Approval from the Energy Regulatory Commission allowed MTerra Solar to develop dedicated transmission facilities and directly connect to the Luzon grid.

This high-voltage integration ensures that the project can deliver utility-scale renewable power reliably across the region, strengthening grid stability as renewable penetration increases.