The Energy Regulatory Commission (ERC) of the Philippines has approved Terra Solar Philippines Inc. (TSPI)’s application to develop and own dedicated transmission facilities for the MTerra Solar Project – taking both records of being the country’s largest and one of the world’s largest solar-plus-battery installations.
The MTerra Solar Project, located across Nueva Ecija and Bulacan on Luzon island, will feature 3.5GW of solar capacity and 4.5GWh of battery energy storage.
Developed by TSPI, a wholly owned subsidiary of SP New Energy Corp (SPNEC), the project will connect to the Luzon grid through its own point-to-point transmission network.
The interconnection will use the existing 500 kV Nagsaag–San Jose transmission line and the planned 500 kV San Isidro substation.
In its decision issued on 8 October 2025, the ERC placed the value of the transmission facilities at around PHP 14.2bn and noted that construction was approximately 90% complete as of September.
The regulator has also imposed a permit fee of PHP 106.86m and instructed TSPI to submit a compliance report and finalise an operations and maintenance (O&M) agreement with the National Grid Corporation of the Philippines (NGCP).
While the ERC granted TSPI the authority to build and own the transmission system, it denied the company’s request to operate and maintain the facilities, confirming that NGCP will handle O&M responsibilities subject to applicable charges.
The Commission also highlighted potential delays related to the San Isidro substation, as NGCP has yet to secure approval for its capital expenditure plan.
The first phase of MTerra, consisting of 2.5GW of solar and 3.3GWh of battery storage, is scheduled to begin operations by February 2026, with full completion targeted for 2027.
As of July 2025, 54% of Phase 1 was complete, with 778 MW of solar already installed – making it the largest solar facility in the Philippines.
Valued at PHP 200bn and supported by $600m in foreign investment, the MTerra Solar Project is expected to supply up to 850 MW of baseload solar power to Meralco under a power supply agreement, contributing significantly to the nation’s renewable energy goals.
