Electricity prices in the Wholesale Electricity Spot Market (WESM) fell to their lowest level in seven months in September as abundant supply and weaker demand eased pressure on the power grid.

Independent Electricity Market Operator of the Philippines Corporate Planning and Communications manager Arjon B. Valencia said on Monday that system-wide average supply rose by 0.5 percent to 20,712 megawatts (MW) in September, while demand declined by 2.9 percent to 13,640 MW.

The wider gap between supply and demand expanded the available margin to 5,194 MW from 4,578 MW in August.

Sharp decline

Valencia said this contributed to a sharp decline in average market prices, which dropped from P4.59 per kilowatt-hour (kWh) in August to P3.04 per kWh in September — the lowest recorded since February this year.

Similar trends were observed across all major grids. In Luzon, prices fell due to lower demand and higher supply, even with increased power exports through the high-voltage direct current link.

In the Visayas, prices also declined alongside reduced power flow from Mindanao, while in Mindanao, prices dropped amid lower export volumes to the Visayas.

No major plant outages

“There were no major plant outages affecting the September billing period, contributing to the overall decrease in prices,” Valencia said. He added that the September 30 earthquake in the Visayas, which caused multiple tripping of transmission lines and generators, “will be settled as part of the October 2025 billing period.”

The Effective Spot Settlement Price likewise fell to P3.28 per kWh from P5.56 per kWh in August. Spot market volume accounted for 13.7 percent of total traded quantity, down from 15.5 percent, while the total trading amount dropped to P8.84 billion from P15.32 billion.

IEMOP also reported that registered capacities in WESM increased by 214.3 MW to 29,889 MW in September.

System-wide transactions in the reserve market

In the reserve market, system-wide transactions slipped to P4.68 billion from P5 billion in August. Zonal prices for regulation reserves increased in Luzon and Mindanao, while most other reserve prices fell.