Luzon grid on yellow alert anew

by Myrna Velasco – July 19, 2016

from Manila Bulletin

After sudden hike in forecast demand and the forced outages of two power generating units, Luzon grid wobbled anew into “yellow alert” – a condition that could plunge the grid into brownouts if the system would not be very quick on its response.

According to Department of Energy (DOE) spokesperson Wimpy Fuentebella, one unit of the South Luzon Thermal Energy Corporation (SLTEC) at 122-megawatt capacity and the 300MW Block B of the Ilijan gas-fired power facility suffered forced outages close to 8:00 a.m. yesterday (Tuesday).

That then triggered extreme thinning in reserves, prompting system operator National Grid Corporation of the Philippines (NGCP) to declare “yellow alert” situation in the grid.


A yellow alert is not yet into “brownout condition,”  but the reserves will no longer be enough to compensate capacity loss in case further glitches or forced outages will be experienced in the power supply chain.

Fuentebella said the department “is closely monitoring the situation,” but in case the power plants would not be back on-line as expected, Manila Electric Company (Meralco) has already been on alert to call on its interruptible load program (ILP) participants.

He said the SLTEC coal-fired plant was snagged with forced outage because of boiler tube leak. No specific time given yet on when the affected generating unit will be synchronized back to the grid.

On available capacity, the energy department reported that it was at 9,981MW as of 9:00 a.m. Forecast demand though was jacked up to 9,479MW from the original projection of 9,373MW.

It stressed that coordination with Meralco was already in place, and as of 11am Tuesday, 154 ILP participants have confirmed availability for total capacity of 315-320 megawatts.

Meralco added that several power plants have been similarly out due to scheduled maintenance shutdowns. These include the Pagbilao unit 2 at 382MW; Malaya unit 1 at 300MW; Malaya unit 2 at 300MW; and Angat main 2 at 50MW. Another power plant, the Calaca coal-fired facility, had de-rated output of 180MW from 200MW.

“As a result of all these unavailable capacity and relatively high demand, net reserve in the Luzon grid at 11 a.m. and 2 p.m. (Tuesday) stood at 245MW and 64MW, respectively,” the power utility firm noted.