The government invoked an emergency power cutback for some companies last month, a report claimed Monday, a measure opponents of a nuclear-free policy say proves the country could run dangerously low on electricity if reactor operations are halted.

The report submitted by the Korea Power Exchange to Rep. Kim Moo-sung of the minor opposition Bareun Party said the companies were instructed to reduce their power usage for three hours on July 12 and for four hours on July 21. 

The government had adopted a system in 2014 that allows it to ask companies that joined a voluntary program to lower power consumption during peak times. In return, such businesses can receive financial compensation.

As of June this year, 3,195 firms have signed up for the program. The purpose of the program, already in place in advanced countries, is to manage the power supply more economically than by building power plants to meet high seasonal demand during the summer and winter months.

Emergency cutbacks are invoked when the power reserve runs out or is expected to fall extremely low from unanticipated demand or from facility breakdowns. They were used five times in the past prior to July.

The Moon Jae-in administration declared a nuclear-free policy, vowing to stop the construction of new reactors and shutting down those that are aged, and to replace the power supply with clean and renewable energy sources. The policy is contested by opponents who argue that it will increase electricity costs for households and raise the risk of a power shortage. 

The Korea Power Exchange said the latest corporate power cutbacks were caused by a partial operational glitch of a power generator in the case of the July 12, and by the anticipated surge in power demand triggered by high temperatures on July 21.

Electricity demand on July 21 hit a record for this year with 84,586 megawatts, lowering the power reserve to 12.3 percent.

Critics charged that the government was trying to maintain the reserve rate to shut out the arguments of nuclear-free policy opponents who say the reserve rate could have fallen to a single digit if the government had not asked for the cutbacks.

"We were not trying to artificially raise the reserve rate," an official from the Ministry of Trade, Industry and Energy said. "The program compensates companies who voluntarily participate. It is not true that we forcibly demanded power cutbacks." (Yonhap)