“Underbuilt” lines from the Peninsula Electric Cooperative, Inc. (PENELCO) caused the grid disturbance last Saturday, resulting National Grid Corporation of the Philippines (NGCP) to declare red and yellow alerts. 

“These underbuilt distribution lines are constructed underneath NGCP’s transmission lines and are within the grid operator’s right of way,” NGCP said in a statement. The lines breached the safety clearance along the 230 kilovolt (kV) Hermosa-BCCP line causing the transmission outage. 

The grid operator has requested PENELCO to remove the underbuilt lines. 

“We are also doing necessary coordination with PENELCO to remove the underbuilt lines within the transmission corridor. We appeal to other electric cooperatives to check their facilities and take the needed action to prevent similar incidents,” NGCP said. 

The red alert raised over Luzon Grid caused power interruptions on Saturday afternoon affecting 1.6 million consumers within the Manila Electric Co. (MERALCO) franchise area. 

The alert was lifted on Saturday at 5:30 PM, but a yellow alert followed suit until 10:19 PM “to allow affected generating plants to ramp back up,” NGCP explained. 

The NGCP also declared a yellow alert on the Luzon Grid on Monday, June 20 after several power plants went ton forced outages. Available capacity in the grid was around 12,351 megawatts (MW) while the demand was at 11,456 MW. 

The power plants that went on forced outage include the 150 MW Unit 1 of the Southwest Luzon Power Generation Corporation (SLPGC) plant, the 50 MW SLPGC Units 3 and 4, the 300 MW Unit 2 Sem-Calaca Power Corporation, and two generating units of the Mariveles coal plant totaling 632 MW. 

The yellow alert was lifted at 2:49 PM following receding system demand.