The average price of power on the Wholesale Electricity Spot Market (WESM) declined 33.8 percent to P3.04 per kilowatt hour (kWh) in September, the lowest in the last seven months, from P4.59 per kWh the previous month, the Independent Electricity Market Operator of the Philippines (IEMOP) said Monday.
The WESM operator noted an improved supply for the billing period August 26 to September 25 at 20,712 megawatts (MW) against a lower demand which stood at 13,640MW, resulting in an increased margin of 5,194 MW, up from 4,578 MW in August 2025.
IEMOP said these conditions were observed across the regions with supply increasing and demand decreasing. The higher margin compared to the previous billing month led to lower prices.
In Luzon, prices dropped significantly due to lower demand and higher supply, even with increased power exports through the HVDC (high-voltage direct current). The average power rate declined 31.7 percent to P2.57 per kWh, with supply at 14,681MW. Demand stood at 9,595MW.
WESM rates in the Visayas also registered a decline. From P6.4 per kWh, it dropped 37 percent to P4.02 per kWh. Supply inched up to 2,440MW while demand went down four percent to 1,945MW.
In Mindanao, WESM prices settled at P4.19 per kWh, 37 percent lower than the P6.66 per kWh registered from a month ago. The grid’s available supply stood at 3,592MW. Demand grew to 2,100MW.
IEMOP said there were no major plant outages affecting the September billing period, contributing to the overall decrease in prices. *While Visayas experienced an earthquake on September 30 that caused multiple tripping of transmission lines and generators, this will be settled as part of the October 2025 billing period,’ it said on Monday
In terms of system-wide generation mix, renewable energy (RE) contributed 26% of total generation. Coal increased its share from 50.6% to 55.1%. Hydro generation continued its upward trend, rising from 12.6% to 13.5%, due to rainy season that was intensified by typhoon.
Meanwhile, the share of natural gas and oil-based decreased, with natural gas dropping from 22% to 17%, and oil-based generation from 0.9% to 0.5%. Solar and geothermal generation also decreased their share from 4.0% to 3.7% and 7.8% to 7.6%, respectively. Approximately 25 percent, or 2.34 terra wat of total customer transactions were purchased from retail market for this billing period.
During the period, IEMOP said the system-wide reserve market transactions decreased from P5 billion to P4.68 billion.