Average system-wide prices at the Wholesale Electricity Spot Market (WESM) rose slightly to P3.99 per kilowatt-hour (kWh) in July from P3.86 per kWh in June on lower supply margins.
“Based on the data…there was a slight increase in prices… because we are in this period where we have plant outages,” said Isidro Cacho Jr., vice president for trading operations of the Independent Electricity Market Operator of the Philippines (IEMOP) in a briefing.
He said power plants moved their maintenance schedules to after the election period, having not conducted them during the summer.
According to IEMOP, the system-wide average supply for June 26 to July 25, 2025, decreased 3.2 percent to 20,754 megawatts (MW) from June. This was mainly due to major plant outages in Luzon, including mostly cheaper power sources such as GNPower Dinginin, Ilijan gas, Quezon Power, and San Gabriel units during the first and second week of the billing period.
IEMOP also reported that demand fell to 13,812 MW, a 5-percent decline, driven by cooler temperatures and the onset of the rainy season. Similar conditions were observed across the regions.
Meanwhile, Cacho said the tight reserve supply situation in the Visayas grid may translate into an increase by an average of P0.30 to P0.40 per kWh in August, which could push up systemwide average prices up to P5 per kWh.
“Hopefully, if it increases in the Visayas, maybe an additional P0.30. Our expectation is that it will increase. We don’t see it exceeding P5, or maybe around P5, based on our initial projection. It’s still not as high, I would say. But we will see a slight increase,” said Cacho.
The Visayas grid was placed on yellow alert for several days early this month due as several plants went on outage. A yellow alert is issued when the operating margin is insufficient to meet the transmission grid’s contingency requirement.
