UPDATE 1-S.Korea offers power bill relief as heatwave spurs demand

* Reduces power bills by $245 mln for July-Aug

* Expects to lower bills by 19.5 pct on avg per household

* Says power supply sufficient to meet demand (Recasts, adds S.Korea’s energy min’s comments, background)

SEOUL, Aug 7 (Reuters) - South Korea will cut residential electricity charges by 276.1 billion won ($245 million) over July and August to ease the burden on households cranking up their air conditioners during a searing heatwave.

The measure is expected to reduce power charges for the average household from state-run utility Korea Electric Power Corp (KEPCO) by 19.5 percent, Paik Un-gyu, Minister of Trade, Industry and Energy said on Tuesday.

The move comes as sweltering summer heat has sparked a public backlash over KEPCO’s progressive electricity billing system, under which households pay higher rates for power as usage increases.

Paik said the government would also look at longer-term changes.

“This is a temporary measure against a disaster level-heatwave,” he told a news briefing. “We will discuss with parliament and devise measures to reform the overall electricity billing system.”

Under the current system, residential users are bracketed in three bands, and pay bills depending on the amount of electricity consumption. The minimum rate is charged at below 200 kilowatts per hour (kWh), but this will be raised to below 300 KWh for July and August, the energy ministry said.

The system has already been revamped from a six-band tariff two years ago, after residential users complained they were afraid to turn up their air conditioners for fear of heavy bills.

Paik said the government would look at sharing the cost of the temporary relief with KEPCO to ease costs for the firm, which supplies all of the country’s household electricity.

The ministry said the country’s power supply was currently sufficient to meet demand. Coal and nuclear power together make up about 70 percent of South Korea’s total electricity needs.

$1 = 1,126.7000 won Reporting By Jane Chung; editing by Richard Pullin