Thin electricity reserves caused by technical problems at the Lopez-owned San Gabriel power plant in Batangas forced authorities to declare a “Yellow Alert” for the Luzon grid Wednesday morning, the Department of Energy said.

The near-shortage was only eased early in the afternoon after the government-owned Malaya power plant — kept as backup power supply in the event of shortages — was activated to augment the generation capacity in the country’s main island.

According to information from the National Grid Corporation of the Philippines, and released by the DOE, the San Gabriel plant tripped at 8:05 a.m. on Wednesday due to “boiler feed pump trouble,” sapping the grid of 414 megawatts of power.

Coupled with the earlier forced outage at the Kalayaan power plant, where “excitation system trouble” decreased supply by another 177 MW, the total generation capacity of the Luzon grid declined to 9,196 MW compared to total demand of 8,629 MW.

The relatively thin reserve level of 567 MW forced authorities to declare a yellow alert status from 10 a.m. to 4 p.m.

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