## 4 Analysis and Interpretation of Results
### Extreme Price Dynamics: Highs and Lows  
Electricity price fluctuations are significantly influenced not only by RES generation, but also by the dynamics of extreme events such as daily price peaks and troughs. This section focuses on the characterisation of the evolution of maximum and minimum prices over the course of the day, month, and year, with particular attention on their relationship with the intensity of RES generation and the daily profile of solar radiation and wind conditions. The aim is to identify systematic patterns in the timing and intensity of the extremes across different geographical areas and seasons. The analysis is based on hourly or 15 min data and uses quantitative indicators such as the range of prices during the day (the difference between the maximum and minimum), the frequency of occurrence of outliers in specific time windows, and statistical characteristics of the price distribution. These indicators make it possible to assess the non-linear effects of variable production on price dynamics and to identify periods of increased risk of extreme fluctuations. The results presented in this section offer an empirical basis for a better understanding of the mechanisms leading to the emergence of extreme prices and provide valuable information for the design of market strategies, the optimisation of resource flexibility, and the design of support mechanisms under conditions of high RES penetration. A scientific analysis of the maximum and minimum electricity prices in the European countries studied between 2015 and 2024 reveals significant changes in the range of daily price volatility, with the most extreme values recorded during the energy crisis in 2022. The scientific treatment of the data shows that prior to 2022, the absolute daily difference between the minimum and maximum price was relatively stable, ranging from around 100 to 180 \(\upepsilon\)/MWh. The lowest price spread values identified by this study were recorded between 2015 and 2019: in Germany 179.7 \(\upepsilon\)/MWh (2015), in Poland 113.97 \(\upepsilon\)/MWh (2019), in Slovakia 121.7 \(\upepsilon\)/MWh (2016), in the Czech Republic 110.0 \(\upepsilon\)/MWh (2015), and in Estonia 127.1 \(\upepsilon\)/MWh (2017). These scientific results reflect the stability of market conditions before the onset of significant external shocks. In terms of scientific analysis, 2022 represents a major turning point, with a sharp increase in peak prices and total daily price spreads in all markets analysed. The scientifically processed data shows extreme peak prices in France (2989 \(\upepsilon\)/MWh), Germany (2325 \(\upepsilon\)/MWh), and Estonia (4000 \(\upepsilon\)/MWh). Significant increases in volatility were also evident in Poland (754.7 \(\upepsilon\)/MWh), Slovakia (910.2 \(\upepsilon\)/MWh), and the Czech Republic (893.5 \(\upepsilon\)/MWh). These results clearly confirm the impact of a number of concurrent factors, including the military conflict in Ukraine, the disruption of natural gas supplies, escalatingcommodity prices, and growing market uncertainty. Compared to previous years, the measured differences represent a several-fold increase in maximum daily price fluctuations, a scientifically significant phenomenon. Further scientific analysis of post-2022 developments suggests that although most markets are showing signs of stabilisation, volatility remains at a significantly higher level than before the COVID-19 outbreak. In Germany, the second-highest daily price difference was identified in 2023 (1024 \(\upxi\)/MWh), with volatility escalating again in 2024 to 2461 \(\upxi\)/MWh. Similar trends were scientifically confirmed in France, where increased volatility was already observed in 2021 (686 \(\upxi\)/MWh). Slovakia and the Czech Republic recorded the second-highest absolute price differences in 2024 (996 \(\upxi\)/MWh and 983 \(\upxi\)/MWh, respectively).