MANILA, Philippines — For two straight days, the Luzon grid has been placed under yellow alert anew following the derated capacity of the SMC Consolidated Power Corp. (SCPC) Units 1 to 4.

The National Grid Corporation of the Philippines (NGCP) announced on Thursday that the Luzon grid would be under yellow alert from 1 p.m. to 10 p.m.

"A yellow alert is issued when the operating margin is insufficient to meet the transmission grid's contingency requirement," NGCP said in an advisory.

SCPC's derated capacity at 150 megawatts each exacerbates the power supply condition in the Luzon grid following the unplanned outage of 417.4 MW San Gabriel power plant that started on July 16.

NGCP said 10 power plants were now running derated capacity.

The unavailable power supply in the grid further increased to 1,893.5 MW on Thursday from 1,652.7 MW on Wednesday.

On July 16, the NGCP placed the Luzon grid under yellow alert for six hours between 3 to 9 p.m., but lifted the status by 4 p.m.