MANILA (UPDATE 4) --  Meralco issued another warning about brownouts that may be implemented in parts of Metro Manila and nearby provinces because of thin power reserves in the Luzon grid. 

This was after the National Grid Corporation of the Philippines extended the red alert status in Luzon up to 11 p.m. due to the outage of 2 additional plants, Kalayaan 1 and 2 which generate 180 megawatts each. 

Meralco said the following areas may be affected by manual load dropping or brownouts at these hours: 

The NGCP said manual load dropping, or rotating brownouts were first implemented at 4:15PM with rotational power interruptions affecting parts of northern Luzon.

"A red alert status is issued when power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirement," the NGCP said. 

Meralco advised the public to check its Facebook for updates.

"Just in case, please charge your mobile phones and other essential gadgets," Meralco said.

Luzon grid on red alert on Tuesday afternoon

In an earlier Facebook post, Meralco said it was able to avoid implementing rotating brownouts thanks to the cooperation of large power users. 

"This is partly due to the help of our big-load customers, which collectively de-loaded around 300 MW under the interruptible load program (ILP)," Meralco said.

"We thank our partners in the private sector in embodying the spirit of bayanihan and malasakit through the ILP, which has been beneficial in ensuring continuity of electricity service particularly when supply is tight," it added. 

But the company also said it will continue to monitor the situation and provide updates as needed.

President Ferdinand Marcos Jr. meanwhile said he has instructed the Department of Energy " to closely monitor and coordinate with all stakeholders to address the situation." 

"I have also directed all government offices to set the standard in conserving energy and minimizing power consumption," Marcos said.

"At this time, it is crucial that we all work together to ensure a stable power supply for the next couple of days. Let's adopt energy-efficient practices and stand together to overcome this challenge," the President added.

The DOE earlier said it was already closely monitoring the situation, and coordinating with the NGCP and all generation companies on the current power supply condition.

"In Luzon, the DOE has instructed all distribution utilities (DUs), including the Manila Electric Company (Meralco) and electric cooperatives (ECs), to activate their Interruptible Load Program (ILP) to help reduce the overall demand in the grid," the DOE said.

It urged industrial and commercial establishments to minimize the use of power during peak hours, and reminded government offices to conserve energy and reduce power consumption.  

“While we continue to monitor and ask our power plant operators to work on restoring full operations, we can maximize our energy efficiency efforts as we go through this period of extreme heat. Flexible work arrangements and other conservation measures would also be helpful. The extremely high temperatures have been affecting the operations of power plants in the grid,”  Secretary Raphael Lotilla said.

Households were also urged to minimize electricity use during peak hours and avoid using aircon and elevators if possible, to reduce the strain on the grid.

A Red Alert was issued for the Luzon grid from 2 p.m. to 4 p.m. and 6 p.m. to 9 p.m. on Tuesday, while a Yellow Alert was declared from 1 p.m. to 2 p.m. and 4 p.m.to 6 p.m., and 9 p.m. to 11 p.m. following the unscheduled outages of some generating plants in Luzon.

The NGCP earlier said 19 power plants are on forced outage, while 3 others are running on derated capacities, which means power supply is depleted by 2,117.3 megawatts. 

A yellow alert was also issued in the Visayas Grid from 2 p.m. to 4 p.m. and 6 p.m. to 7 p.m. today due to outages and deration of several generation facilities.

National Grid Corporation of the Philippines warns of 'tight' power supply this summer