Although the power situation in Mindanao appears to be normal, the situation on the island remains precarious, as the energy grid continues to hold “thin reserves,” according to the National Grid Corp. of the Philippines (NGCP).
This means that any simultaneous emergency shutdowns, as what happened last week, may again result in rotating brownouts in Mindanao, explained Cynthia Alabanza, NGCP spokesperson and adviser for external affairs.
“That’s why we continue to be on the lookout for any unplanned outages, even if the Mindanao grid has normalized. We still expect Mindanao to be on a yellow alert every so often because of the thin reserves as brought about by the reduced capabilities of the facilities owned by the National Power Corp.,” Alabanza said in a phone interview.
Since last week, the Mindanao grid has been put on “red alert” due to the power generation deficiency caused by the scheduled maintenance of some power plants and the unexpected shutdown or reduced capability of other facilities.
A red alert status means that the grid does not have any reserves to address power supply deficiencies, even temporary ones.
As such, power distributors are forced to implement rotating brownouts. A yellow alert refers to the inability of the grid to meet the required reserve levels, but may not require load shedding.
As of Thursday, NGCP data showed that reserves were low at only 75 MW.
During such periods of generation deficiency, NGCP is forced to implement a Mindanao-wide power load curtailment to maintain the grid’s security and reliability.
“It is NGCP’s obligation under the law and its franchise to ensure that the grid operates at an optimum level with due consideration for safety, security and reliability,” Alabanza said.
“The level of curtailment is based on the Mindanao generation deficiency matrix issued to us by the Power Sector Assets and Liabilities Management Corp. NGCP does not, by itself, determine which franchise area or distribution utility gets what portion of the available supply. We only follow a matrix supplied to us,” she clarified.
Last October 19, NGCP implemented the so-called “load curtailment” based on PSALM/ Napocor’s matrix due to a power supply deficit of 12 MW. This persisted until October 24 when the supply deficit rose to 45MW, Alabanza said.