Frequent Curtailment
With the increasing utilization of renewable energy sources such as solar and wind power, which generate varying outputs depending on weather conditions, the frequency of “curtailment,” which means generating less power than planned, in nuclear power generation has risen fourfold compared to two years ago.
Particularly, unlike base load power generation, which is controlled by the power authorities to regulate power output, renewable energy generation involves private enterprises, and the increase in artificially controlled power output necessitates the need for conflict resolution mechanisms.
According to the “Analysis of National Audit Issues” released by National Assembly’s Legislative Research Services on Aug. 17, as of the end of May this year, there were 23 instances of curtailment in nuclear power generation. It was reported that the adjusted power output amounted to 4,130 megawatts (MW) in terms of capacity.
The reason for choosing to lower the power generation of nuclear plants below a planned level is due to concerns about the safety of the power grid. If power generation exceeds the capacity of the transmission facilities in the power system, it can lead to a “blackout,” where the supply of power is disrupted. This is why the authorities responsible for power regulate power generation, including nuclear plants, as needed.
The occurrences of curtailment in nuclear power generation have been rapidly increasing in recent times. Last year, there were a total of 21 instances of curtailment, while in 2020 and 2021, there were only 4 and 6 instances, respectively. Considering the fact that there have been 23 instances of curtailment in just the first half of this year, it signifies an increase of at least fourfold compared to two years ago. In comparison to the previous year, the number of curtailments in a span of five months has already exceeded that annual count.
The backdrop for such power generation adjustments is the growing presence of renewable energy facilities like solar and wind power. Due to the nature of renewable energy, where power generation varies depending on factors such as sunlight, wind speed, and wind direction, power authorities are unable to directly control power output.
Given the predominant involvement of private entities in the renewable energy sector, friction between these private businesses and power authorities over output control has been emerging. In June of this year, 12 solar power operators in the Jeju region filed a lawsuit in the Gwangju District Court against the Ministry of Trade, Industry and Energy, along with Korea Electric Power Corporation (KEPCO) and Korea Power Exchange (KPX), seeking to overturn the imposition of output restrictions. Their claim is that the insufficiently grounded output control has caused losses for private businesses.
The Legislative Research Services noted that some solar power generation companies have filed lawsuits claiming that the output control measures are unlawful. The government's stance is that compensating for solar and wind power output control is difficult as it is a measure to prevent instability in the power grid. The report also emphasized the need to review whether there are procedures in place for gathering the opinions of stakeholders when implementing changes in energy-related regulations or new policies.