The Independent Electri

city Market Operator of the Philippines (IEMOP) reports that average supply in the Wholesale Electricity Spot Market (WESM) rose to 22,218 MW for the May 2025 billing period, a 4.1% increase from April. Meanwhile, demand climbed 2.9% to 15,169 MW, driven by persistent extreme heat throughout the month.

The increase in supply outpaced demand growth, resulting in a wider margin of 4,945 MW — up from April’s 4,585 MW — and pulling the system-wide average price down to 4.01 PHP/kWh from 4.52 PHP/kWh. IEMOP highlighted that this trend differs from May 2024, when price

s rose, noting that the “difference was due to a higher supply margin in May 2025.”

Luzon and Visayas followed the national trend, with higher supply and demand leading to lower prices. Mindanao, however, saw a unique case: supply rose while demand slightly dipped by 0.9%, also resulting in lower prices. No market intervention was recorded during the period.

On the generation mix, coal increased its dominance slightly to 59.9% (from 59.8%), while natural gas held steady at 17%. Renewable energy accounted for 22%, while hydro rebounded to 7.7% from 7.3%, breaking a downward trend observed since January. Solar and oil-based sources saw marginal declines.

Retail market activity comprised 21% (2.17 TWh) of total customer transactions. The Effective Spot Settlement Price (ESSP) dropped to 4.13 PHP/kWh from 4.82 PHP/kWh last month. Spot market transactions also decreased to 19.4% of total traded quantity, down from 22.4%, contributing to a decline in trading value from PHP 17.17 billion to PHP 13.55 billion.

What do these shifts in supply, demand, and pricing mean for your operations or investments? Let’s discuss how this development impacts procurement strategies and energy planning across the sector.

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