In June 2026, the system‑wide average supply decreased to 21,133 MW, a 1.1% decline from May 2026, while average demand decreased to 15,454 MW, or 1.9% lower than the previous billing month. Despite a reduction in both supply and demand, the system-wide average supply margin increased to 3,691 MW, compared to 3,629 MW in May 2026.
The supply-demand conditions varied across the three regions. Supply margin in Luzon increased by 278 MW, while Visayas and Mindanao declined by 83 MW and 132 MW, respectively, due to higher outage levels, supply constraints relative to demand, grid alert issuances, and variations in HVDC flows. Although the overall system supply margin improved, localized supply tightness and reserve deficiencies led to the manifestation of Constraint Violation Costs (CVCs) in real-time market prices. Consequently, this led to the increase in system-wide average market price to 9.56 PHP/kWh, from 7.79 PHP/kWh last May 2026 – a 22.7% increase for June 2026.
In Luzon, average supply increased by 149 MW, while average demand decreased by 234 MW. Nevertheless, the region’s average price had a 13.3% incline from 7.02 PHP/kWh to 7.95 PHP/kWh. Although supply improved, several large generating units experienced forced outages throughout the billing period, contributing to tighter market conditions and elevated prices. The billing period also recorded the highest average regional price on 29 May 2026 at 17.86 PHP/kWh.
In the Visayas, average supply and demand declined by 178 MW and 12 MW, respectively, from the previous billing month. As the reduction in supply significantly exceeded the decline in demand, average prices increased by 41.7%, from 10.20 PHP/kWh to 14.46 PHP/kWh. Throughout the billing period, there were multiple issuances of yellow and red alerts, and market interventions due to generation deficiencies. The highest average regional price was recorded on 22 June 2026 at 21.68 PHP/kWh. In addition to tight energy supply conditions, recurring reserve deficiencies further contributed to higher market prices.
Mindanao exhibited a similar trend to Visayas, where average supply and demand decreased by 213 MW and 55 MW, respectively. Consequently, average prices increased by 37.5%, from 9.28 PHP/kWh to 12.75 PHP/kWh. The highest average regional price was recorded on 22 June 2026 at 22.75 PHP/kWh due to outages of several large generating units. Similar to Visayas, reserve deficiencies were observed in Mindanao and contributed to higher market prices.
Under normal conditions, the Visayas grid is supported by power imports from Luzon through the Leyte–Luzon HVDC interconnection. Throughout June 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 67.46% of the billing period, higher than the 46.06% observed in May 2026. Additionally, the Mindanao-Visayas HVDC flow also operated at maximum, with a transfer limit of 450 MW, for 39.36% compared to 51.84% from the previous billing period. These limitations continued to restrict the flow of lower-cost Luzon generation into the Visayas, contributing to the price separation among Luzon and Visayas-Mindanao.
Several special pricing conditions were issued in the billing period. Administered Pricing (AP) tagging at 0.01% (Luzon), 7.71% (Visayas), and 0.01% (Mindanao) of the time following imposition of several market interventions due to the implementation of Manual Load Dropping. Meanwhile, Price Substitution Methodology (PSM) reached 17.71% (Luzon), 15.24% (Visayas), and 17.20% (Mindanao) of the time due to congestion and price separation, while sustained high prices resulted in Secondary Price Cap (SEC) levels of 11.10% (Luzon), 14.75% (Visayas), and 15.55% (Mindanao) of the time under the new cumulative price threshold of 12.413 PHP/kWh capped at 7.423 PHP/kWh.
Several generating units across all grids experienced outages throughout the month. In Luzon, forced outages across various technologies had the highest daily cumulative outage of 3,060.5 MW, mostly from Hydro, Coal, and Natural Gas, while planned outages across various technologies had the highest daily cumulative outage of 758.30 MW. In Visayas, forced outages from various technologies have the highest daily cumulative outage of 2,295.23 MW, mostly from Coal and Geothermal, with 490.1 MW of planned outages from Geothermal. This means that Visayas relied heavily on imports from Luzon and Mindanao to meet its local demand. In Mindanao, forced outages have the highest daily cumulative outage of 1,186.70 MW, and 237.50 MW for planned outages from Hydro technology.
“Grid alerts are more commonly associated with the summer months, when electricity demand is typically higher. This year, however, continued generating-unit outages and tighter regional supply conditions extended beyond the summer period, particularly in the Visayas and Mindanao. At the same time, new generating capacities are progressively entering the market, which should help support the country’s growing electricity requirements.”, Engr. Isidro E. Cacho Jr., IEMOP Vice President for Trading Operations, mentioned.
Moreover, in terms of system-wide generation mix, renewable energy (RE) accounted for 21% of total generation. Coal-fired generation slightly decreased from 58.6% to 57.9%, while Natural Gas generation remained unchanged at 18%. Oil-based generation increased from 1.7% to 2.2%. Solar generation declined from 6.7% to 6.2%, while Hydro generation increased from 5.4% to 6.2%, primarily due to higher water availability brought about by the rainy season. Pumped storage hydro generation slightly decreased from 0.9% to 0.7%, while Wind generation slightly declined from 0.6% to 0.5%. For Biomass and Battery units, they remained unchanged at 1.0% and 0.2%, respectively.
Energy spot market volume decreased in June 2026, accounting for 15.1% of total traded quantity from 17% in May 2026. Correspondingly, the total trading amount increased from 29.50 billion PHP to 36.57 billion PHP due to relatively higher prices.
Reserves/Ancillary Services Market
In the reserve market, zonal prices decreased except for Luzon’s Regulation Up and Dispatchable Reserve, Visayas’ Contingency and Dispatchable Reserve, and Mindanao’s Contingency and Dispatchable Reserve. The total system-wide reserve market transactions increased from 6.03 billion PHP in May to 6.65 billion PHP in June, largely due to increased trading amounts in Luzon, Visayas, and Mindanao. With an increase in overall energy consumption during the month, the reserve market’s Contribution Rate slightly increased from 0.56 PHP/kWh to 0.61 PHP/kWh, indicating a higher cost allocation per kWh of energy and higher reserve market transactions.
In Luzon, all reserve commodities recorded higher trading amounts during the June billing period. Regulation Up and Regulation Down maintained relatively stable spot levels, while Contingency Reserve saw reduced spot exposure due to a higher ASPA share from 52% to 60%. In contrast, Dispatchable Reserve saw higher spot exposure due to a lower ASPA share from 34% to 29%.
In the Visayas, an opposite trend was observed, with decreased trading on all commodities due to a decline in spot quantities from 212 MW to 149 MW. In Mindanao, all commodities recorded lower trading amounts, except for Contingency and Dispatchable reserves with maintained ASPA participation of 85%, which resulted in lower clearing prices and reduced spot exposure.
“June 2026 was a volatile month for the WESM. While the country had sufficient supply overall, outages, reserve shortages, and transmission limitations created tighter conditions in some regions. Market prices reflected these conditions and showed where additional supply, reserves, and transmission capacity were most needed.”, Engr. Cacho added.
