The lights of key landmarks in Korea will be turned off for five minutes Tuesday night, including at Gwanghwamun and N Seoul Tower in Seoul, Busan's major bridge Gwangandaegyo and the landmark Cheomseongdae in Gyeongju, North Gyeongsang Province.

The event is to mark Energy Day, with an estimated 1.27 million people in South Korea taking part, which is more than twice the number of participants last year.

The Ministry of Trade, Industry and Energy announced that lights-out events will start 9 p.m. to commemorate the 20th Energy Day.

First held in 2004, Energy Day was established to raise awareness of the importance of energy conservation following Korea’s record-high electricity consumption on Aug. 22, 2003.

Major landmarks will turn out their lights simultaneously in the evening, while earlier Tuesday afternoon a campaign was held to raise air conditioning temperatures by 2 degrees Celsius.

All households willing to join in the energy savings are free to participate. There is also an event led by local residents to turn out apartment lights all at once.

The government expects to save approximately 470 megawatt-hours of electricity through the event. One megawatt-hour of electricity is enough to run two refrigerators for about a year.

“While the government is making efforts to ensure a stable power supply, wise energy consumption is necessary as it is ultimately citizens who determine the energy needs,” said Trade, Industry and Energy Deputy Minister Cheon Young-gil.