INITIAL average price of electricity in the Wholesale Electricity Spot Market (WESM) for the entire country decreased in September, according to the Independent Electricity Market Operator of the Philippines (IEMOP).

Based on IEMOP’s data released Tuesday night, the increase in power supply availability amid the lower power demand during the period led to the price drop.

As of September 25, average price per kilowatt hour (kWh) in WESM for the entire Philippines was at P3.88, a 34.7 percent slump compared to P5.94 per kWh in the full month of August.

IEMOP said total average demand in the country for the period went down by 3.4 percent to 13,700 megawatts (MW) from 14,186 MW, while average supply increased by 3.2 percent to 20,348 MW from 19,718 MW.

“Low average preliminary WESM price this month is attributable to sustained large system supply margin, primarily because of cooler weather condition,” IEMOP said in a statement.

As of September 25, average price per kWh in WESM was at P3.80 per kWh for Luzon, down by 39.1 percent from P6.24 per kWh in the full month of August.

The average WESM price for Visayas during the period stood at P4.56, a 34.2 percent drop from the full month of August’s P6.93 per kWh.

However, the Mindanao grid posted a 3.3 percent increase in average WESM price per kWh for the period at P3.48, from P3.37 per kWh last August.

IEMOP attributed the higher average WESM price in Mindanao to the effects of the outage of some power plants in the region during the third week of the billing period.

The initial September data presented by IEMOP could still change depending on developments for the full month.