Amid distress from scorching weather temperature, massive number of consumers in Luzon had to live through the agony of rotational blackouts of at least two-hour duration due to strained power supply in the grid following a transmission line tripping that was compounded by the forced outages and de-rating of power plants. System operator National Grid Corporation of the Philippines (NGCP) raised "red alert" status in the grid starting 1:00pm on Monday, May 8,  that lasted until 4:00pm; and an extended series from 6:00pm to 8:00pm. In its franchise areas, Manila Electric Company (Meralco) divulged that as of 5:00pm, more than 320,000 customers had been afflicted with power interruptions; while there are no immediate data yet of rotational brownouts from the electric cooperatives (ECs) servicing other consumers in the Luzon grid. Among the areas affected within Meralco’s service area had been parts of Rizal, Cavite and Laguna; and a number of cities in Metro Manila, including Las Pinas, Makati, Marikina, Muntinlupa, Paranaque, Pasig, Quezon City and Taguig. NGCP primarily blamed the forced outages and de-rating of power plants as the main factor which had thrown electricity supply on a knife’s edge, with it emphasizing that 1,350 megawatts had been suddenly taken out from the system. Nevertheless, in an official statement of the Department of Energy (DOE), it was specified that the Bolo-Masinloc 230 kilovolt (kV) line 2 of NGCP had tripped; and that led to the unplanned outage suffered by the two generating units of the Masinloc coal-fired power plant in Zambales. “As the situation emanated from a transmission line tripping, the DOE has instructed the NGCP to explain within 24 hours the circumstances that caused the outages,” the department stressed. NGCP primarily stated that “five (5) power plants are on forced outage; while three others are running on derated capacities, for a total of 1,354MW unavailable to the grid. Apart from the Masinloc plant, the other power generating assets that suffered forced outages had been unit 1 Calaca coal-fired power plant; units 1 and 4 of the Binga hydropower facility – which altogether shaved off at least 940MW of supply from the grid. Additionally, it was reported that the generation capacity of Sual plant’s unit 1 had been extremely de-rated at 67MW; and Sual unit 2 at 227MW – from their original capacities of 647MW each. As of 4:13pm on Monday (May 8), however, plant operator TeaM Energy Philippines conveyed that the capacity of the generating units had already been increased to 583MW for Sual unit 1; and 537MW for Unit-2. The other generating facilities with de-rated or reduced scale of electricity production had been unit 2 of the Calaca plant at 120MW from 300MW capacity – bringing the total reduced capacity to 414MW. For the Calaca generating facility, the plant operator relayed that “unit 1 went on emergency outage last May 1 due to boiler tube leak; while unit 2 is running on de-rated capacity due to generator vibration.” On the Binga hydropower plant, asset owner SN Aboitiz Power (SNAP) qualified that the plant is “under outside management control (OMC) outage,” which entails that there is “hydrological constraint due to the low reservoir elevation.” This ‘red alert’ status in Luzon deviates from earlier forecast of the energy department that supply in the main power grid will not be reaching such proportion, although it qualified that the differentiating factor will be the forced outages of power plants and other technical glitches in the system. Further, the DOE pointed out that “the reduced generation supply in Luzon affected export to the Visayas grid, which resulted in the declaration of yellow alert at 5:00pm and 6:00pm.” The agency similarly highlighted that “following the declaration of red and yellow alerts in the Luzon grid, the NGCP as the system operator declared a suspension of the Wholesale Electricity Spot Market in the Luzon grid,” adding that “the suspension of the WESM will effectively shield the public from volatile prices that may arise from the unavailability of some power plants.”