Challenges of renewable integration in Kosovo: A technical study of balancing reserve needs

The integration of renewable energy sources (RES), particularl y wind power, into national power systems introduces significant operational and technical challenges, especially in countries with limited system flexibility, such as Kosovo.This study examines the impact of wind power on Kosovo's balancing reserve requirements using high-resolution operational data from two existing wind farms -Kitka (32.4 MW) and Selac (103.4MW).The analysis assesses short-term variability and forecast errors across 1-minute, 15-minute, and hourly intervals.The standard deviation () of wind power variability was applied to estimate the impact on short-term reserves.This method is effective for estimating reserve requirements resulting from wind power integration, provided that operational data from wind farms is available.A confidence level of 4 is applied to capture over 99% of potential imbalances, in line with EU network code requirements.Additionally, the results are compared with both the variability and the unpredictability of wind power output.The findings indicate that the current wind capacities already cause substantial system imbalances, requiring additional frequency restoration reserves (FRR) of +31 MW (upward) and -40 MW (downward), with forecasting errors and variability reaching 35% of installed capacity within 15-minute intervals.Scenariobased modeling, aligned with Kosovo's national energy strategy -which targets 600 MW of installed wind capacity by 2031 -suggest that future balancing reserve needs may rise to 129.6 MW (upward) and 156.6 MW (downward).Although the analysis focuses solely on operational data from WPP and excludes factors like demand fluctuations, outages, or market trading, it provides valuable into the operational challenges facing Kosovo's power system.The results point to an urgent need for investments in system flexibility, including battery energy storage, and enhanced regional cooperation to strengthen reserve adequacy and ensure grid stability.