A Seoul court on Thursday ruled in favor of the state-run electric power supplier, dismissing a suit filed against the country's controversial electricity rate system which critics say excessively charges users.

In August 2014, a total of 17 plaintiffs filed the case against the Korea Electric Power Corporation, saying the power supplier made unfair profits by overcharging ordinary citizens.

The plaintiffs cited the Act on the Regulation of Terms and Conditions, which stipulated that any clause which is "unreasonably unfavorable to customers" shall be null and void.

The Seoul Central District Court, however, said the current terms and conditions cannot be deemed as such based on the evidence provided by the plaintiffs.

"The current system is based on a progressive billing system, while also giving discounts to those who need social support," the court said. "The electricity rate system is designed differently in every country, considering their respective social circumstances and energy supply."

The ruling came amid public outcry among households here that electricity bills soared as they increasingly relied on air conditioners to cope with the unprecedented heat wave this summer.

As part of efforts to curtail electricity consumption, a household pays 60.7 won ($0.05) per kilowatt for the first 100 kilowatts in a month. But the price shoots up to 709.5 won per kilowatt -- nearly 12 times more than the first price -- if they consume more than 500 kilowatts per month.

The system, however, is not applied to industries that account for over half of the country's energy consumption.

Thursday's ruling was the first in a series of similar cases pending at the country's district courts. (Yonhap)