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Visiting Korea Hydro & Nuclear Power Cheongsong Pumped Storage Power Plant

The upper dam of Korea Hydro & Nuclear Power Cheongsong Pumped Storage Power Plant located in Cheongsong-gun, Gyeongbuk.
[Photo by Korea Hydro & Nuclear Power]

[Asia Economy, Cheongsong=Reporter Lee Jun-hyung] The Korea Hydro & Nuclear Power Cheongsong Pumped Storage Power Plant is located in Cheongsong County, Gyeongbuk. About 600 meters from the power plant entrance, traveling through an underground tunnel by vehicle, two large generators come into view. The generation method is simple. The generators rotate due to the 347-meter height difference between the upper and lower dams. Each generator has a generation capacity of 300MW, with a 10-meter-high turbine shaft rotating 300 times per minute to produce electricity.

The pumped storage power plant is not a baseload power source. This means it is not the main power source in the domestic electricity supply system. This is why pumped storage plants are less familiar compared to other power sources such as nuclear power and liquefied natural gas (LNG) combined cycle power plants.

However, the role of pumped storage plants is by no means insignificant. Their true value is demonstrated when there is a gap in the domestic power grid. If baseload power sources like nuclear power plants unexpectedly stop operating due to accidents, pumped storage plants can supply electricity within 3 minutes. This contrasts with large power plants such as nuclear and thermal power plants, which require several hours to tens of hours to reach maximum output. In this sense, pumped storage plants act as a kind of energy storage system (ESS) that provides emergency power in crisis situations.

Blackout ‘Maginot Line’

Pumped storage plants are considered the ‘last line of defense’ against blackouts. They use surplus electricity during periods of low power demand at night or when renewable energy generation such as solar power is high to pump water from the lower dam to the upper dam. When there is a problem in the power grid or a sudden surge in electricity demand, water from the upper dam is sent to the lower dam to turn the underground generators. The use of surplus electricity is intentional to minimize electricity consumption and enhance grid stability.

Pumped storage plants also serve as a ‘power plant for power plants.’ When large-scale power plants such as nuclear plants stop operating, the amount of electricity required to restart them is considerable. Pumped storage plants supply the ‘kindling’ power needed to restart these large plants within 3 minutes. In fact, Korea Hydro & Nuclear Power was able to prevent a blackout in September 2011 by urgently operating a pumped storage plant during a large-scale blackout crisis.

The importance of pumped storage plants is increasing. This is because the government is steadily increasing the share of renewable energy generation to achieve carbon neutrality by 2050. As the share of renewable energy, which has high intermittency depending on weather, increases, grid stability inevitably decreases. Recently, large-scale ESS facilities composed of lithium-ion batteries have been built alongside solar power plants for this reason. Unlike lithium-ion batteries, pumped storage plants can serve as an ‘eco-friendly ESS’ that is not affected by global supply chain instability.

Speeding Up Pumped Storage Development

The global pumped storage market is steadily growing. According to Korea Hydro & Nuclear Power, the global pumped storage generation capacity is 165GW. The International Hydropower Association (IHA) expects an additional 78GW of pumped storage plants to be constructed by 2030. In Europe, major countries such as Germany and Ireland have announced plans to expand pumped storage plants in preparation for increasing the share of renewable energy generation.

Accordingly, Korea Hydro & Nuclear Power is accelerating the construction of additional pumped storage plants. It is currently promoting new pumped storage projects in three regions: Pocheon in Gyeonggi, Yeongdong in Chungbuk, and Hongcheon in Gangwon. The first to be completed is the Yeongdong Pumped Storage Power Plant, scheduled to operate in 2030 with a generation capacity of 500MW. Korea Hydro & Nuclear Power plans to operate the Hongcheon Pumped Storage Power Plant (600MW) and the Pocheon Pumped Storage Power Plant (700MW) starting in 2032 and 2034, respectively.

Localization of pumped storage plants is also being pursued. Except for Chilbo Hydropower Unit 2, all major equipment for domestic hydropower and pumped storage plants are imported. This is because there are virtually no domestic companies producing hydropower equipment. Korea Hydro & Nuclear Power plans to localize 300MW-class large pumped storage plant equipment by 2030. A Korea Hydro & Nuclear Power official said, "Due to the characteristics of the domestic hydropower industry, it was inevitable to use foreign equipment," adding, "We are currently promoting a government project to localize hydropower equipment targeting Hwacheon Hydropower Unit 2."

This content was produced with the assistance of AI translation services.