Changes in short term river flow regulation and hydropeaking in Nordic rivers

TLDR

Short‑term river flow changes are crucial for assessing hydropower’s environmental impacts, and as renewable energy use rises, rapid energy market fluctuations may intensify hydropeaking, potentially compromising Nordic river ecosystems. The study investigates the driving forces behind hydropeaking in Nordic rivers using hourly discharge data from 150 sites. The authors analyzed hourly discharge data from 150 sites and examined how rising wind power production affects hydropeaking. Hydropeaking levels in Nordic rivers are high and have risen over the past decade, especially recently, suggesting that expanding renewable energy infrastructure may further amplify hydropeaking.

Abstract

Abstract Quantifying short-term changes in river flow is important in understanding the environmental impacts of hydropower generation. Energy markets can change rapidly and energy demand fluctuates at sub-daily scales, which may cause corresponding changes in regulated river flow (hydropeaking). Due to increasing use of renewable energy, in future hydropower will play a greater role as a load balancing power source. This may increase current hydropeaking levels in Nordic river systems, creating challenges in maintaining a healthy ecological status. This study examined driving forces for hydropeaking in Nordic rivers using extensive datasets from 150 sites with hourly time step river discharge data. It also investigated the influence of increased wind power production on hydropeaking. The data revealed that hydropeaking is at high levels in the Nordic rivers and have seen an increase over the last decade and especially over the past few years. These results indicate that increased building for renewable energy may increase hydropeaking in Nordic rivers.