Consumers may face higher electricity bills this month as the Manila Electric Co. (Meralco) anticipates an increase in both generation and transmission charges, driven by tight supply conditions and soaring power spot market prices.

Joe Zaldarriaga, Meralco vice president and head of corporate communications, said early data points to a possible rate hike following significant movements in the Wholesale Electricity Spot Market (WESM) in March.

“We expect higher WESM prices due to the tight supply situation in the last supply month,” Zaldarriaga said in a statement to reporters on Tuesday. “Initial information shows an increase of over 1,000 megawatts (MW) in average demand, while the average capacity on outage was also nearly 1,000 MW.”

The Independent Electricity Market Operator of the Philippines (IEMOP) reported that WESM prices surged by 95.5% in March, hitting P5.34 per kilowatt-hour (kWh) — almost double February’s average of P2.73 per kWh. The rise was attributed to stronger demand amid dwindling supply due to unscheduled power plant outages.

Despite these upward pressures, a bit of relief is expected through the rollout of a refund approved by the Energy Regulatory Commission (ERC), which Meralco began implementing this month.

“We hope that the start of the implementation of the refund approved by the [Energy Regulatory Commission] will help mitigate these possible increases in these bill components. This is equivalent to around 20 centavos per kWh downward adjustment for residential customers starting this month,” Zaldarriaga said.

The P19.96-billion refund will be spread out over 36 months and will appear as a separate line item in consumer bills. For residential customers using 200 kWh per month, the refund could reduce their bill by about P38.

Last month, Meralco’s electricity rates already saw an increase of P0.2639 per kWh, bringing the average rate to P12.2901 per kWh. This translated to an additional P53 in monthly bills for typical households consuming 200 kWh.

As power demand continues to rise amid sweltering heat, Meralco is urging its more than eight million customers in Metro Manila and nearby provinces to conserve energy where possible.