MANILA - Power distributors have started implementing rotating power outages across Luzon as they try to balance supply from power plants, Energy officials said Monday.

The Luzon grid went on yellow alert on Monday morning and red alert, the highest warning, by 1 p.m. due to the high heat index that pushed demand for power, maintenance work and unscheduled outages at key power plants in Luzon, the Department of Energy said in press briefing.

The low gas pressure from the Malamapaya, a critical supply source for gas-fired power plants in Luzon, also contributed to the problems, the DOE said.

On Sunday, the NAIA area in Pasay City registered the highest heat index in Metro Manila at 45 degrees celsius.

Power reserved earlier dropped to below 400 megawatts, the DOE said.

Rotating power outages began this afternoon in parts of Isabella, the entire province of Quirino, Olongapo City, parts of Quezon, parts of Camarines Sur, and parts of Metro Manila, the DOE said.

"There is a possibility that this yellow and red alert will still last for the next couple of days," Energy Assistant Secretary Redentor Delola said.

The NGCP earlier said it might implement manual load dropping in the following areas on May 31:

2 p.m. to 3 p.m.

• INEC (parts of Ilocos Norte)
• LUELCO (parts of La Union)
• ZAMECO I and ZAMECO II (parts of Zambales)
• QUEZELCO I (parts of Quezon)
• CANORECO (parts of Camarines Norte)
• APEC (parts of Albay)
• MERALCO (parts of Metro Manila)

Schedule may change if the demand falls below projection, the agency said.

Meralco, meanwhile, released a tentative list of areas that could be hit by power outages due to supply issues. The list includes:

• Bulacan
• Quezon
• Rizal
• Cavita
• Laguna
• Metro Manila (including parts of Caloocan, Manila, Marikina, Muntinlupa, Pasig, and Quezon City)

FULL LIST: MERALCO ADVISORY

• Meralco implements rotational brownouts due to low reserves

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