The National Grid Corporation of the Philippines (NGCP) issued red and yellow alerts for the Visayas grid on Tuesday, August 11.
The Visayas grid will be under yellow alert from 1 p.m. to 4 p.m. and from 8 p.m. to 10 p.m., while a red alert will be in effect from 4 p.m. to 8 p.m.
The alerts were triggered by the unavailability of several large coal-fired power plants in the region and limited power imports from Mindanao.
The grid has an available capacity of 2,226 megawatts (MW) against a peak demand of 2,410 MW.
NGCP said five plants were on forced outage, while other generating units had been unavailable since previous months and years. In addition, 14 plants were operating at derated capacities for a total of 924.7 MW of unavailable capacity.
Among the factors contributing to the alerts were the unavailability of Visayas-based large coal plants Therma Visayas Inc. Unit 1, Therma Visayas Inc. Unit 2, and Cebu Energy Development Corp. Unit 1.
Power imports from Mindanao were also limited due to the extended outage of SEC 2, the maintenance outage of GNPK 2, and the emergency shutdown of GNPK 1 due to a boiler tube leak. High system demand further constrained the available power supply.
NGCP said a red alert status is issued when power supply is insufficient to meet consumer demand and the transmission grid’s regulating requirement.
Meanwhile, a yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement.
