In May 2026, the system‑wide average supply increased to 21,374 MW, a 2.7% incline from April 2026. Coincidently, the average demand increased to 15,755 MW, or 9.4% higher than the previous month. These supply-demand levels resulted in a tighter system supply margin of 3,629 MW, compared to 4,427 MW in April.
With the decrease in the system‑wide supply margin, regional supply–demand conditions showed mixed outcomes. Supply margins in Luzon, Visayas, and Mindanao declined by 470 MW, 72 MW, and 257 MW, respectively, due to higher outage levels, variations in HVDC flows, and supply shortfall leading to issuance of grid alert. These conditions lead to an increase in the system‑wide average market price to 7.79 PHP/kWh, from 5.63 PHP/kWh last April – a 38.5% increase for May 2026, noting that the previous billing month was under the Modified AP mechanism.
In Luzon, average demand increased by 1,103 MW from the previous billing month, reaching a year-to-date peak of 14,359 MW. While average supply also increased by 719 MW, the higher increase in demand compared to supply resulted in a lower supply margin by 500 MW, primarily due to more frequent planned and forced outages and the issuance of grid alert status. Consequently, Luzon’s average market price rose to 7.02 PHP/kWh from 5.63 PHP/kWh.
In the Visayas, average demand increased by 182 MW from the previous billing month, reaching a year-to-date peak of 2,770 MW. However, supply was constrained by approximately 608.5 MW of forced outages, resulting in a lower average supply of 2,360 MW. These conditions reduced the supply margin by 72 MW and led to the issuance of grid alerts. Consequently, the region’s average market price rose to 10.20 PHP/kWh from 5.63 PHP/kWh.
In Mindanao, average supply was 3,505 MW, lower by 37 MW compared to the previous month. The region continued to export power to the Visayas via the Mindanao–Visayas HVDC interconnection, contributing additional supply in the Visayas. Meanwhile, demand increased by 66 MW, reaching 2,808 MW – the year-to-date peak with no grid alert conditions declared. As a result, the supply margin declined by 257 MW, contributing to an increase in the average market price from 5.63 PHP/kWh to 9.28 PHP/kWh.
Under normal conditions, the Visayas grid is supported by power imports from Luzon through the Leyte–Luzon HVDC interconnection. Throughout May 2026, the Leyte-Luzon HVDC facility was either operating at its maximum Luzon‑to‑Visayas transfer limit of 250 MW or at a security‑limited transfer level for 46.06% of the billing period, higher than the 25.90% constraint observed in April 2026. Additionally, the Mindanao-Visayas HVDC flow also operated at maximum, with a transfer limit of 450 MW, for 51.84% compared to 44.01% from the previous billing period.
In May 2026, pricing conditions were issued. Administered Pricing (AP) was implemented for 20.37% of the duration in Luzon, 19.75% in Visayas, and 16.67% in Mindanao following the market suspension from April 26 to 30 and system operator-initiated interventions due to Manual Load Dropping. Meanwhile, Price Substitution Methodology (PSM) was implemented for 18.31% of the time in Luzon, 18.37% in Visayas, and 20.03% in Mindanao due to congestion and price separation. Sustained high prices also resulted in application of the Secondary Price Cap (SEC) for 3.89% of the time in Luzon, 4.31% in Visayas, and 4.71% in Mindanao under the new Cumulative Price Threshold of 12.413 PHP/kWh capped at 7.423 PHP/kWh.
“Electricity prices in the market increased as demand for power rose during the summer season while some power plants were unavailable due to maintenance activities and unexpected outages”, Engr. Isidro E. Cacho Jr., IEMOP Vice President for Trading Operations mentioned.
Several generating units across all grids experience outages throughout the month with daily peak outage levels identified for each of the three regions. In Luzon, forced outages across various technologies, mostly from Hydro and Natural Gas, reached 5,931.40 MW, while planned outages amounted to 168.50 MW. In Visayas, forced outages from various technologies, mostly from Coal and Geothermal, recorded 782.70 MW, with 5 MW of planned outages from oil-based. In Mindanao, forced outages peaked at 560 MW, and 300 MW for planned outages from Coal and Hydro technologies. Additionally, continued congestion along the 230 kV Leyte–Cebu transmission corridor limited internal power transfers and contributed to localized price separation, particularly affecting nodes in Leyte.
Moreover, in terms of system-wide generation mix, renewable energy (RE) accounted for 21% of total generation. Coal-fired and Natural Gas generation slightly increased from 58.4% to 58.6%, and 18% to 17%, respectively. Oil-based generation significantly increased from 0.2% to 1.7% and was utilized during peak demand periods and unforeseen outages. On the other hand, Geothermal generation declined from 8.2% to 7.5%, Hydropower from 6.0% to 5.4%, Solar generation from 7.1% to 6.7%, and PSH from 1.0% to 0.9%. Wind generation increased slightly from 0.4% to 0.6%. For Biomass and Battery units, their shares remained unchanged at 1.0% and 0.2%, respectively.
Energy spot market volume increased in May 2026, accounting for 17% of total traded quantity from 16.3% in April 2026. Correspondingly, the total trading amount increased from 19.47 billion PHP to 29.55 billion PHP due to relatively higher prices.
In Luzon, all commodities recorded lower trading amounts, with Regulation maintaining relatively stable spot levels, while Contingency and Dispatchable Reserves saw reduced spot exposure due to a higher ASPA share from 42% to 52%; and 22% to 34%, respectively.
In the Visayas, the opposite trend was observed, with increased trading across all commodities due to increased spot quantities from 205 MW to 229 MW. The combination of higher spot MW clearing and increased marginal reserve prices drove the overall rise. In Mindanao, all commodities recorded lower trading amounts, mainly from increased ASPA participation from 69% to 79%, which resulted in lower clearing prices and reduced spot exposure.
In the reserve market, overall, zonal prices decreased except for Luzon’s Dispatchable Reserves, Visayas’ Regulation UP and Dispatchable Reserve, and Mindanao’s Contingency and Dispatchable Reserves. The total system-wide reserve market transactions declined from 6.89 billion PHP in April to 6.03 billion PHP in May, largely due to reduced trading amounts in Luzon, Visayas and Mindanao. With an increase in overall energy consumption during the month, the reserve market’s Contribution Rate slightly decreased from 0.68 PHP/kWh to 0.56 PHP/kWh, indicating a lower cost allocation per kWh of energy.
