Variable renewable generation across the monitored markets declined from 3,934.85 GWh in Week 30 to 3,502.73 GWh in Week 34, down 11.0%. The reduction was driven almost entirely by wind. Regional wind output fell 26.4%, from 1,554.06 GWh to 1,143.82 GWh, while solar generation decreased by just 0.9%.
The different production patterns of wind and solar affect how much generation remains available across the day. Stable solar output can support supply during midday hours. A large wind decline removes generation across a wider range of hours, increasing the residual need for hydro, thermal generation and imports, particularly in the evening when solar output disappears.
Wind and solar changes reflected in Greece and Türkiye
Greece showed a pronounced wind-led shift between Week 30 and Week 34. Greek wind generation fell 48.2%, while solar output rose by 4.3%. Despite the increase in solar, Greece’s weekly electricity price rose 41.2% from Week 33 to €144.41/MWh, the largest increase among the markets covered.
Türkiye also recorded a substantial reduction in variable renewables over the same comparison period. Variable renewable generation fell 27.0%, with wind output down 36.5%. The figures indicate that changes in wind availability were a key element of the week’s tightening conditions.
Divergent renewable trends across Romania, Serbia and Bulgaria
The regional renewable picture was not uniform across all monitored systems. Romania’s variable renewable generation increased by 37.8%, Serbia’s rose by 48.9%, and Bulgaria’s grew by 21.1%. This dispersion aligns with differentiated national price movements even as most markets moved higher.
The Week 34 data also points to wind availability as the more significant renewable variable for the week rather than solar alone. Solar generation remained relatively resilient, but the electricity market tightened significantly nonetheless. Wind availability therefore became the dominant factor behind the observed market conditions during that period.
Hourly forecasting and cross-border effects as wind falls
The market implications extend to forecasting practices for traders, generators and renewable asset owners. The data reinforces the importance of hourly production forecasts rather than relying on installed capacity alone. A system can have substantial renewable capacity yet still face high wholesale prices if available technologies do not produce during critical hours.
The pattern also reflects how correlated wind shortfalls can reduce the value of imports for balancing. When wind production declines across multiple interconnected countries at the same time, neighbouring systems experience similar deficits, limiting import coverage. In that scenario, the regional market depends more heavily on dispatchable generation and on available cross-border surplus.
Week 34 illustrates this transition in timing between resources. The tightening did not occur because solar production collapsed; instead, it coincided with wind generation disappearing at a point when expensive dispatchable capacity was becoming more important.
