By Myrna Velasco
It’s a frantic Monday in the power sector and the Filipino consumers as the Luzon grid were placed on a four-hour ‘yellow alert’ due to tight supply as a result of the scheduled Malampaya shutdown and power plant outages.
System operator National Grid Corporation of the Philippines (NGCP) raised the yellow alert condition in the country’s major power grid from 10:01 a.m. to 11 a.m. on October 14 (the morning peak demand hour); then 1:01 p.m. to 4 p.m. which are considerably peak hours in the afternoon.
Yellow alert does not necessary entail the imminent occurrence of rolling brownouts, but this manifests lack of required reserves – and if more generating plants would suddenly be taken out from the system, power supply-demand balance could turn for the worse.
The Malampaya gas field has been on scheduled maintenance downtime from October 12-15, a very short duration which could have spared the power system from distress if not for the unprecedented forced outages of some generating units.
In particular, one unit of the Sual power plant with 647-megawatt had descended into unplanned shutdown, and that exacerbated supply availability in the grid.
Adding to the grid’s capacity deficiency had been the forced outages on the two units of the Avion gas-fired power plant – taking out another 100MW from the Luzon power system.
Several generating units were also on de-rated capacity: including unit 1 of the Pagbilao coal-fired plant which has just been yielding 80MW vis-a-vis rated capacity of 382MW; as well as the two units of the Calaca coal-fired plants which just have aggregate generation of 430MW instead of 600MW.
In line with the ongoing maintenance of the country’s commercial gas field, one unit of the Ilijan gas-fired power plant had also been scheduled for simultaneous downtime, hence, reducing further capacity being available to the grid.
It has been noted that the Luzon power system cannot also lean much on capacity export from the Visayas grid as the latter has also been encountering supply strain at times.
Power utility giant Manila Electric Company (Meralco) had warned on this probable supply tightening as early as September, thus, this current social torment on the supply situation is no longer a surprise.
Meralco emphasized that if the situation will turn for the worse, it will call on the participants of the interruptible load program (ILP) to switch on their generating sets so supply in the grid could be reinforced.