Introduction

The Philippines consist of several islands, the bigger of which are the islands of Luzon, mainland Mindanao, and the six biggest islands in the Visayas (Cebu, Negros, Panay, Bohol, Leyte, and Samar). These eight dominant islands constitute the major electrical systems of the country with a combined power demand of around 7,000 MW.

The geographical formation of these islands, the site specific nature of indigenous energy sources, and the need to expand the generating capacity at the same time maintain individual system reserves prompted NPC to consider the interconnection of these island grids. The interconnection aims to maximize utilization of indigenous energy at the same time optimize the reserve capacity of the individual system.

At present, the biggest islands in the Visayas are interconnected to each other with limited transfer capacity. The interconnected grid is linked with Luzon grid to effectively share the reserve capacity of the system. Mindanao grid still remains isolated from the rest of the system.