South Korea's 'Water Batteries': Pumped-Storage Hydropower Faces Dilemmas Amid Renewable Energy Push

The Hankyoreh takes us deep into the Yecheon Pumped-Storage Power Plant, a marvel of engineering that functions as a 'water battery,' storing excess electricity generated during off-peak hours and releasing it when demand surges. This facility, and others like it, are increasingly vital in South Korea's transition to renewable energy, acting as the crucial buffer needed to stabilize a grid increasingly reliant on intermittent sources like solar and wind power.

“

Pumped-storage power generation is often called the 'emergency room' of the power grid in the electricity industry. This is because it absorbs and stores surplus electricity when it is abundant and supplies power the moment it is needed, preventing large-scale blackouts.

The article highlights the growing importance of pumped-storage hydropower, often referred to as the 'emergency room' of the power grid due to its rapid response capabilities. Unlike fossil fuel or nuclear plants that require hours to start up, pumped-storage facilities can generate electricity within minutes, making them indispensable for preventing blackouts. Recent years have seen a rise in their utilization rates and a return to profitability, driven by changes in electricity pricing and the expansion of renewables.

“

The utilization rate of Yecheon Pumped-Storage Power Plant was 13.4% last year. Although still low, it has increased compared to the single-digit levels in the past.

However, the expansion of this technology is not without its challenges. The Hankyoreh points to significant environmental concerns, particularly the extensive forest destruction required to build the upper and lower reservoirs. The proposed Hongcheon project, for instance, faces strong opposition from environmental groups due to its impact on a valuable native pine forest. Furthermore, the construction process can lead to the displacement of local communities, as seen in Yecheon where several households lost their homes to the reservoir.

“

The net profit of all pumped-storage power plants operated by K-water turned to a surplus in 2022 from a deficit of 102.4 billion won in 2021, recording a surplus of 88.2 billion won last year.

Economically, the high initial investment costs for pumped-storage plants have long been a subject of debate, especially given their primary role as storage rather than direct energy producers. While the technology remains valuable for its ability to store large amounts of energy for extended periods, the rapid advancement and falling costs of battery energy storage systems (ESS) present a potential alternative. The Hankyoreh concludes that while pumped-storage hydropower will likely retain a role, its future development must proceed cautiously, prioritizing the minimization of environmental damage and carefully balancing its advantages against emerging storage technologies.

“

Although energy storage facilities are essential as renewable energy expands, recently, battery energy storage system (ESS) technologies, which can replace pumped-storage power generation due to price drops, are rapidly increasing.