The forced outage of the 1,200-megawatt Sual coal-fired power facility in Pangasinan triggered rotating brownouts of about seven hours that affected large areas in the Luzon grid on Monday, industry officials said.

In a media advisory sent by utility firm Manila Electric Company (Meralco), it cited “generation deficiency” as the cause of the rolling power outages.

Meralco said it resorted to manual load dropping starting 1:38 p.m. on Monday “due to the generation insufficiency brought about by the outage of Sual unit 1 at 12:41 p.m.”

The utility firm said the plant has a generation capability of 540MW but one of its units was at 350MW generation before it tripped. The outage was traced to a feed water pump trouble at the plant.

“The rotating brownouts are expected to last until 9 p.m. (of Monday) due to the insufficiency in the power supply,” Meralco said, adding that several areas in Metro Manila have been mainly affected by the brownouts.

It was learned from system operator National Grid Corporation of the Philippines that one unit of Sual was already out of the grid for several days already due to coal supply lack. Its other unit went on forced outage Monday, triggering the power supply interruptions.

San Miguel Corporation President Ramon S. Ang said “Team Energy rejected PNOC-EC’s (Philippine National Oil Company-Exploration Corporation) coal delivery” to the plant earlier.

PNOC-EC, according to Sual’s independent power producer administrator San Miguel Energy Corporation,\ has been contracted to supply coal for the plant.

Plant operator TeaM Energy explained that they rejected PNOC-EC’s coal shipment “because these are not according to specifications. We cannot just use any coal because it will destroy the plant.”

One unit of the 600-MW Masinloc coal plant was also reported on shutdown “due to leak in its boiler”, aggravating the shortage.

Another coal facility on shutdown is the 460-MW Quezon power plant for a scheduled annual maintenance.

The power supply situation in the Luzon grid could face “more critical condition” in the coming days with the scheduled maintenance shutdown of the Malampaya facility. Shell Philippines Exploration B.V. (SPEX) confirmed in a text message that Malampaya will be shut down for 30 days starting February 10.

The reduced contribution of the coal plants is being exacerbated by low availability of electricity from hydroelectric plants because of the El Nino phenomenon.

With the critical power situation, industry players are calling on the government, particularly the Department of Energy, to draw up precautionary measures before the situation gets out of hand.