Manila, Sept. 17 -- The cost of ancillary service (AS) drove the rise of transmission rates in August 2025, which increased by 7.09 percent to PHP1.4171 per kilowatt hour (kWh), the National Grid Corporation of the Philippines (NGCP) said Tuesday.

NGCP said the average transmission rate in July is PHP1.3233/kWh.

It said AS rose by PHP0.0787/kWh last August from the previous month's PHP0.6659/kWh.

NGCP said "AS rates are pass-through costs for power supplied by AS providers during supply-demand imbalance."

"Charges are remitted directly to generating companies with bilateral contracts with NGCP, and to the Independent Electricity Market Operator of the Philippines (IEMOP) for AS sourced from the Reserve Market," it said.

NGCP clarifie...