Grid alerts expose Philippines’ power system vulnerability

By Francis Allan L. Angelo

The yellow alerts raised over the Luzon and Visayas power grids on April 16 have renewed calls for the Philippines to shift toward a more resilient and decentralized energy system.

The Institute for Climate and Sustainable Cities (ICSC) said the simultaneous grid alerts underscore a recurring vulnerability: the country’s heavy reliance on a few large, baseload-centric power plants leaves the entire system exposed when even one facility goes offline.

On April 16, at around 3 p.m., the Excellent Energy Resources, Inc. (EERI) 1, 2, and 3 plants, with a combined capacity of 1,262 MW, and the Ilijan Block A and B plants, with a combined capacity of 1,200 MW, experienced unplanned outages simultaneously. Both facilities are liquefied natural gas (LNG) plants utilizing the same LNG terminal.

While the outages lasted only a few hours and have since been resolved, ICSC said they highlight the fragility of a system overly reliant on a few large facilities.

Multiple plants were also operating at derated capacity. Among the biggest contributors to the supply shortfall were the Sual 1 plant, which had only 235 MW available out of a dependable capacity of 647 MW, and Sual 2, with 300 MW available out of 647 MW — both running at less than half capacity.

According to the National Grid Corporation of the Philippines (NGCP), the unplanned outages and derations resulted in the loss of 5,137 MW of baseload capacity in the Luzon grid.

The NGCP also noted that the unavailability of the Magat 1, 2, 3, and 4 hydropower plants, with a combined capacity of 345 MW, contributed to the yellow alert. However, ICSC pointed out that the Magat shutdowns were scheduled maintenance operations under the NGCP’s Grid Operating and Maintenance Program.

The Visayas grid, which was already operating on net negative reserves, felt the ripple effect of the Luzon outages. In its Philippine Power Outlook Report, ICSC had warned that the Visayas grid is vulnerable to grid alerts due to its reliance on high-voltage direct current imports from Luzon and Mindanao.

The report also cautioned that unplanned outages beyond the Department of Energy’s (DOE) approved schedule could significantly worsen the situation — a scenario that played out on April 16 when additional unexpected outages at the EERI and Ilijan LNG facilities tightened supply conditions and triggered yellow alerts across both grids.

A significant portion of the unavailable capacity came from LNG-fired power plants, including the EERI and Ilijan facilities, and not just from the scheduled Magat maintenance. ICSC said this underscores how closely overall system conditions are tied to the performance and location of major generating units.

To break the cycle of grid alerts, ICSC urged the Philippines to move toward a more decentralized, diversified, and flexible power system where the outage of a single facility does not put the entire grid at risk.

The group called for expanding the share of indigenous renewable energy sources, including geothermal, hydropower, solar, and wind, supported by energy storage systems. ICSC said renewables strengthen energy security, improve system resilience, and reduce exposure to volatile global fuel markets.

Heavy reliance on imported LNG continues to tie domestic electricity prices to global fuel price shocks and geopolitical disruptions, the group said, unlike indigenous renewable energy sources that have no fuel costs and help moderate electricity prices in the Wholesale Electricity Spot Market.

Given the country’s archipelagic geography and exposure to extreme weather, ICSC said power generation must be geographically distributed. A more decentralized system allows communities to reduce reliance on a few large plants, improving local reliability and self-sufficiency while reducing the risk of supply disruptions from outages, disasters, or other physical shocks.

Grid reliability will also depend on flexibility rather than additional baseload capacity alone, ICSC said, calling for technologies that can quickly respond to fluctuations in supply and demand, including energy storage systems, modern grid management, and fast-ramping capacity.