Complementarity for Wind Power in Turkey: A Correlation Analysis Using XGBoost
Gökçe Kurucu, Semih YumuşakGeneration from resources such as wind power and photovoltaics is highly variable and relatively unpredictable. This variability incurs costs, especially when wind and photovoltaic generation is low due to weather conditions, necessitating substitution by other energy sources to meet demands through market forces. The extent to which thermal leg or reservoir storage hydropower plants can fill or substitute this gap is a matter of interest. This is explored in the literature through complementarity between variable renewables and alternative energy sources. To address this question, this study uses hourly data from Türkiye for the period between 2015 and 2020, predicting generation from the thermal leg and reservoir storage hydropower plants with XGBoost machine learning algorithm, based on different price and generation levels of wind power. The results indicate a positive correlation between wind power and reservoir storage hydropower, which concludes as the lack of complementarity between these sources in the Turkish context. It is observed that the feed-in-tariff system, which guarantees a price in US dollar per kWh for energy from reservoir storage hydropower, decreases the incentive for substituting wind power, thereby cancelling out the balancing role of the reservoir storage hydropower. Conversely, for positive prices, the natural gas-fueled plants appear to substitute between 63% and 116% of the loss in wind power generation, while the rest of the thermal leg substitutes for 43% to 59% of this loss in wind power, according to our calculations. These outcomes reveal a complementarity (over-substitution in this case) between wind power and the thermal leg.
