Drivers of imbalance cost of wind power: a comparative analysis

In Europe an increasing share of wind power is sold on the power market. Therefore more and more wind power generators become balancing responsible and face imbalance cost that reduce revenues from selling wind power. A comparison of literature illustrates that the imbalance cost of wind power varies in a wide range. To explain differences we indentify parameters influencing imbalance cost and compare them for case studies in Austria, Denmark and Poland. Besides the wind power forecast error also the correlation between imbalance and imbalance price influences imbalance cost significantly. Especially in systems with significant wind shares, an assessment of imbalance cost based on the amount of imbalance and average System Sell and System Buy Prices is therefore not reliable. While imbalance cost rather reflects cash flows within the clearing of imbalances, the presented concept of cost of imperfect forecast is better suited to reflect real cost incurred due to inaccurate wind power forecasts.