Appendix 1. Additional simulation results on price impact

Impact of Polish gas capacity on Nordic prices

Figure 29 presents base prices in Poland and Nordic bidding zones under the sensitivities on Polish gas capacity. The Polish gas capacity sensitivities produce only negligible effects on Nordic prices. This limited impact reflects the weaker integration between Nordic and Polish markets compared to the strong coupling between the Nordics and Germany. Polish base prices, however, decline significantly when more domestic gas capacity is added.

Figure 29. Base prices across bidding zones for the sensitivities on Polish gas capacities, EUR/MWh

Impact of different offshore wind capacities on solar capture prices

Figure 30 illustrates the solar capture prices under different offshore wind sensitivity scenarios. Solar capture prices decline significantly as continental offshore wind capacity increases. This decrease is primarily driven by a base-price effect: higher continental offshore capacity lowers electricity prices during daytime hours when solar generation is high, thereby reducing the capture prices for solar power.

Figure 30. Solar capture prices for the offshore wind sensitivities, EUR/MWh

Development of zero and negative price hours for solar capture sensitivities

Figure 31 illustrates the frequency of zero and negative price hours across the analyzed price zones. While the rise in such hours contributes to lower capture prices, it is only one of several factors driving the decline. Most Nordic zones experience a moderate increase in low-price hours as solar capacity grows, with Danish bidding zones showing the greatest sensitivity due to their strong interconnection with the German market. The shift is considerably more pronounced in Germany, where low-price hours rise by over 50% between the THEMA Base and All High scenarios, reaching roughly 30% of total hours by 2035.

Figure 31. Number of zero and negative price hours for the solar capacity sensitivities

Battery impacts on price spikes

Figure 32 displays the occurrence of extreme price spikes exceeding 500 EUR/MWh across the battery sensitivity scenarios. Expanded battery deployment significantly curtails these episodes, particularly in zones with strong interconnection to Germany such as DK1 and the Norwegian bidding zones. The 4-hour duration storage assumed in the All High scenario proves especially effective at mitigating scarcity pricing during Dunkelflaute periods — in well-connected zones, hours above 500 EUR/MWh are virtually eliminated. By contrast, Swedish and Danish price zones show comparatively limited responsiveness to changes in continental battery capacity.

Figure 32. Number of peak prices above 500 EUR/MWh for the battery sensitivities

Battery impact on zero and negative price hours

Figure 33 displays the number of zero and negative price hours across the relevant price zones. Expanded battery storage capacity reduces the frequency of such hours, with the most substantial decreases observed in Germany and the Danish zones. By contrast, price zones in Norway, Sweden, and Finland show minimal responsiveness to changes in continental battery deployment, both in terms of high-price and low-price hour frequency.

Figure 33. Number of zero and negative price hours for the battery sensitivities

Zero and negative price hours for combined solar and battery sensitivities

Figure 34 shows the number of zero and negative price hours for the combined solar and battery sensitivities. The figure illustrates that the number of zero- and negative price hours in most Nordic zones hardly change when combining the solar and battery sensitivities.

Figure 34. Number of zero and negative price hours for the combined solar and battery sensitivities

Appendix 1. Additional simu­lation results on price impact