The National Grid Corporation of the Philippines (NGCP) appealed for better energy resource planning following a power outage traced to multiple power plant failures that isolated Panay island from the rest of the Visayas grid on Tuesday.
“The unscheduled maintenance shutdowns of the largest power plants in Panay island was the primary cause of the power interruption. We emphasize the need for improved planning to ensure sufficient generation per island, with a well-balanced mix of fuels and technology,” the NGCP said in a statement.
It earlier reported the automated disconnection of three of the largest power plants on the island and the scheduled maintenance shutdown of others, resulting to a total 656-megawatt outage in the Panay sub-grid.
NGCP said maintenance shutdowns and deration of plants outside the Department of Energy’s grid operating and maintenance program also contributed to the lack of power supply.
“We will be restoring loads conservatively by matching loads to restored generation to prevent repeated voltage failure. NGCP is ready to transmit power once it is available. The people must understand we can only transmit power. We do not generate power,” the company explained.
NGCP also said factors outlined in its letter to the Iloilo City government on 11 May 2023 were contributing elements to the power outage on Tuesday.
In that letter, NGCP highlighted the need for resource optimization planning by policy makers to ensure that solutions to power system concerns are approached from all angles with the most efficient ones prioritized.
Given the configuration of the Panay sub-grid and its dependency on variable energy from Negros when it loses internally generated power, the NGCP cited the need to provide sufficient base load power sources to stabilize the system.
NGCP also said stage-3 of the ongoing Cebu-Negros-Panay Stage 3 project is a contributing solution.
As of 4 p.m. Tuesday, 200.1 MW was generated by Panay power plants augmented by 47.5 MW from elsewhere in the Visayas for a total 243.5 MW in served load.
NGCP said the grid needs around 300 MW to stabilize and awaits the remaining power plant with a 135-MW capacity to synchronize back to the grid.
Amid this background, the DOE said the NGCP as system operator is in a position to immediately coordinate with power plants to ensure their respective unit protection and control settings do not cause grid instability that leads to black outs.
“NGCP is in a position to anticipate system disturbance such as what happened yesterday, which unfortunately resulted in the isolation of Panay from the rest of the Visayas grid due to the simultaneous tripping of power plants that caused multiple power interruption affecting other power plants and distribution utilities (DUs),” said Energy undersecretary Rowena Cristina Guevara, in a separate statement.
