The dry spell caused by the El Niño weather phenomenon has impacted the country's power supply as it slashes the generation of power from water sources.

Thus, the Department of Energy or DoE warned that four possible yellow alert occurrences are likely to ensue in Luzon within the rest of the year, which could expose consumers to potential power interruptions.

"There are four potential yellow alerts for Luzon, but none in the Visayas and Mindanao. However, there may be a lower supply in the Visayas at night due to the absence of solar power," Energy Undersecretary Rowena L. Guevara said in an interview with reporters last week.

Guevara explained the DoE's projections were based on the approximately 70 percent decline of hydroelectric power generation as an effect of the El Niño.

A yellow alert is issued when the operating margin is insufficient to meet the transmission grid's regulating and contingency requirements. When this status is in place, all power plants must run normally; otherwise, a red alert may be raised.

A red alert, on the other hand, is issued when supplies are insufficient to meet consumer demand and the transmission grid's regulating requirement.

About two weeks ago, the Manila Electric Co. or Meralco, the country's largest power distributor, confirmed that 850,000 customers across its franchise in Metro Manila, Pampanga, Bulacan, Cavite, Laguna, Batangas, Rizal and Quezon were affected.

Meralco said the incident was triggered by a "sudden plant outage," which prompted an Automatic Load Dropping or ALD that occurred at around 6:45 p.m.

Based on initial reports, the plant outage cited by Meralco was triggered by the tripping of the San Jose-Nagsaag 500KV line trip 2, which led to several plants going offline.

The Energy Regulatory Commission, meanwhile, had asked an Interim Grid Management Committee to start evaluating the cause of the power interruption.

Nonetheless, Energy Secretary Raphael Perpetuo Lotilla assured that the power supply remains sufficient to light up the country, adding that it could even be more stable as new power resources are integrated into the grid within the next two to three years.