Unseasonably high temperatures have raised concerns about nationwide blackouts again this year. Demand for electricity remains high at a time when many power plants are under maintenance, reducing the power reserves to a worrisome level.

For the first time in recent years, the nation experienced rolling blackouts last September ― a series of intentional electrical blackouts affecting small areas in succession as a means of conserving electricity when supply was low.

Korea Electric Power Corp. had to enforce rolling blackouts in Seoul and other areas to avoid a nationwide blackout, as demand for electricity surged when an off-season heat wave hit the nation. Elevators stopped, traffic lights went out and business operations came to a halt.

If no action is taken, the nation will have to brace for similar or worse inconveniences, not just this year but in the years ahead. Power plant construction will reportedly remain behind schedule until 2015.

For most power plants, spring and fall are the seasons for regular maintenance that takes place in sequence. Spring maintenance scheduled for some power plants has been delayed until fall, as the weather is unusually hot for May, pushing up the demand for power.

The highest peak so far this month recorded a whopping increase of 1.73 million kW over last year, lowering the reserves close to the 4 million kW level, at which a contingency plan would be required. Power demand shot up at a time when the capacity for power generation dropped much as a consequence of maintenance at three nuclear power plants and suspended operations at two thermal power plants.

Last week, the Ministry of Knowledge Economy appealed to businesses to conserve power by lowering operations below the normal level during the peak hours from 1-5 p.m. and to households to keep room temperatures higher than before. If the ministry’s campaign is to succeed, it should be combined with incentives ― higher prices for peak hours and lower prices for off-peak hours.

But the conservation campaign is only a stopgap measure. The government needs to change its energy policy in the way it encourages electricity conservation. It is of no help to keep the electricity price low relative to other energy sources.

A modest price increase is considered a viable option to prevent a nationwide blackout. According to one estimate, a 10 percent increase will cut electricity demand 4 percent.