Revisiting Market Power in the Polish Power System

The consequences of the liberalisation electricity markets have been widely discussed in literature emphasising successes or failures privatisation and deregulation. While most developed power systems undergone a form economic transformation, they still require to be monitored analysed assess market power. Polish system is an example wherein potential examined fifteen years ago was summarised as significant. Since then, transformation process changes ownership structure taken place. This study focuses on assessment market. For this purpose, statistics companies were collected processed. Then, structural behavioural measures applied, including concentration ratios, entropy coefficient, Gini Herfindahl–Hirschman Index (HHI), Residual Supply (RSI), Lerner Index. results reveal that, despite dynamic increase renewable capacity, has increased recent years, achieving HHI 2020.9 2021. An lignite hard coal-fired units also observed, indicating high mark-ups by key players. Based quantitative analysis, policy recommendations are outlined reduce negative impact consumers.