Davao Light explains unplanned power outages affecting its franchise area on July 22 and 23

On the afternoon of July 22, 2021 the Mindanao Power Grid encountered two sets of system disturbances due to a transmission line problem and an unplanned outage of a power plant. These caused power outages in many parts of Mindanao affecting customers of Davao Light and Power Co., Inc..


The first system disturbance occurred at 12:44 p.m. due to an unplanned outage of National Grid Corporation of the Philippines (NGCP) 230 kV Toril-Matanao Line 2. This subsequently caused the tripping or automatic shut off of the 300 MW Units 1 and 2 of San Miguel Consolidated Power Corporation (SMCPC) Power Plant in Malita, Davao Occidental.

This abrupt reduction of supply in the power grid has activated the automatic load drop (ALD) scheme or the automatic cutting off of power in certain areas. This is a precautionary measure to maintain system stability and to prevent the grid from collapsing.


Twenty-five percent of Davao Light’s franchise area - the cities of Davao and Panabo, and the municipalities of Carmen, Dujali and Sto. Tomas - experienced this unscheduled power interruption. With NGCP’s clearance, Davao Light performed gradual restoration of power supply in the affected areas between 1:07 p.m. until 1:15 p.m..


The second system disturbance occurred at 1:33 p.m. due to an unplanned outage of the 135 MW Unit 3 of FDC Misamis Power Corporation Power Plant at Villanueva, Misamis Oriental. This activated the ALD scheme once again and power outages were experienced by 12% of Davao Light’s franchise area. In coordination with NGCP and with their clearance, Davao Light restored the power supply gradually in the affected areas between 2:17 p.m. until 4:04 p.m..


The same percentage of Davao Light’s franchise area experienced another unscheduled power outage on July 23 at 2:59 a.m.. This is due to an unplanned shut off of the same unit of FDC power plant which once again resulted in the activation of ALD. Power was restored at 3:30 a.m..


Davao Light deeply apologizes for the inconvenience brought about by these unplanned power outages which were beyond its control.