Power spot prices edged higher in December
Electricity prices at the Wholesale Electricity Spot Market (Wesm) rose in December despite higher system-wide supply, as tighter margins in the Visayas and Mindanao pushed prices upward.
System-wide average supply increased by 1.2-percent month-on-month to 20,233 megawatts (MW), while average demand slipped by 0.5 percent to 13,440 MW. This resulted in a wider supply margin of 4,798 MW, up from 4,572 MW in November.
Data from the Independent Electricity Market Operator of the Philippines (Iemop) showed that reduced margins in the Visayas and Mindanao—down by 136 MW and 245 MW, respectively—offset the overall improvement.
These conditions drove the system-wide average price up to P4.38 per kilowatt-hour (kWh), higher than P3.98 per kWh a month earlier.
Price movements varied across regions.
In Luzon, increased supply coupled with lower demand led to softer prices, with the regional average declining to P2.98 per kWh from P3.52 per kWh.
In contrast, the Visayas saw supply rise by 106 MW but demand grew faster by 181 MW, tightening margins.
Mindanao faced a sharper squeeze, as supply fell by 245 MW while demand increased by 25 MW.
Due to sustained high prices, the secondary price cap was imposed for 213 intervals in the Visayas and 216 intervals in Mindanao. This resulted in average market prices of P7.22 per kWh and P7.82 per kWh, respectively.
Iemop recorded only one market intervention during the period from Nov. 26 to Dec. 25 last year. The intervention occurred on Dec. 13, affecting all three grids after the failure to generate real-time dispatch results.
Meanwhile, the effective spot settlement price for December likewise rose to P5.55 per kWh from P4.57 per kWh in November.
Spot market volume also increased, accounting for 13.2 percent of total traded quantity, up from 12.3 percent. Total trading value climbed to P14.19 billion from P13.13 billion.
In terms of generation mix, renewable energy accounted for 26 percent of total output.
Coal strengthened its share to 56.4 percent, while wind, solar and geothermal energy posted modest increases.
Hydro generation declined to 8.8 percent, while oil-based generation edged up. Natural gas fell to 17 percent from 19 percent.
Meanwhile, total Wesm registered capacity reached 30,085 MW, driven by additional solar capacity.
Reserve market transactions declined to P3.92 billion from P4.1 billion, with most zonal reserve prices easing during the month.
