ERC Approves Prime Solar’s 115-kV Point-to-Point Facility Connecting Maragondon Solar Plant to Meralco

The Energy Regulatory Commission (ERC) has approved Prime Solar Solutions Corp. to construct, own, and operate a dedicated 115-kV point-to-point transmission facility linking its 48.118-MWAC Maragondon Solar Power Plant to the Manila Electric Company (Meralco).

Prime Solar, part of Prime Infrastructure Capital Inc. (Prime Infra) — which holds a controlling stake in Manila Water Co. Inc. and nearly 50% ownership of the Malampaya gas project — received authorization to develop a 60-MVA substation and a single-circuit 115-kV line spanning over 20 kilometers. The approval comes with strict conditions regarding facility use, operation, and potential transfer to the distribution utility.

The interconnection assets were reportedly completed in February 2025 at a total cost exceeding PHP 1.6 billion, with a provisional authority to operate the solar plant issued in March. The ERC assessed a permit fee of around PHP 12 million.

Under the ruling:

The transmission line and substation may only serve the Maragondon plant and must comply with the approved Distribution Impact Study (DIS) and Distribution Asset Study (DAS).

Meralco is responsible for operating and maintaining the facilities, with charges billed to Prime Solar.

Any portion of the line or substation later needed by other users must be transferred to Meralco as a Contribution-in-Aid-of-Construction (CIAC), in accordance with regulations for dedicated point-to-point lines.

Technical assessments by Meralco and the National Grid Corporation of the Philippines (NGCP) confirmed that the solar project’s output could be fully absorbed by Meralco’s TMC-2 substation without requiring additional system upgrades. NGCP noted that “the generation dispatch of the project will be fully consumed by Meralco loads at TMC-2 115 kV Substation with a total demand of 69.45 MW during peak conditions, with no backflow to the Dasmariñas 115 kV facility.”

The ERC reminded Prime Solar that prior regulatory approval for such facilities is “indispensable and non-negotiable”. The company is required to submit compliance documents within 30 days and pay the assessed permit fee within 15 days of receiving the order.