Renewable energy output across South-East Europe increased significantly during calendar week 13, but the composition of that growth reveals a system still grappling with intermittency and uneven resource distribution.
Total renewable generation rose by 12.2% to 3,914.7 GWh, with solar providing the dominant contribution. Solar output surged by 27.7%, reflecting longer daylight hours and improving seasonal conditions. This increase had a noticeable impact on daytime pricing, particularly in markets with higher solar penetration.
Wind generation, by contrast, rose only 4.1%, underscoring the continued variability of wind resources across the region. In several markets, weaker wind conditions limited the overall impact of renewable growth on system balance.
Italy recorded the most dramatic increase, with total renewable output rising by 205.1%, driven by strong performance in both wind and solar. This surge played a key role in reducing Italy’s reliance on thermal generation during the week, although the country remained structurally import-dependent.
Hungary and Serbia also recorded substantial increases, albeit from lower baselines. Hungary’s renewable output expanded sharply due to a spike in solar generation, while Serbia saw a doubling of renewable production, primarily from wind.
However, the regional picture remains highly uneven. Romania and Türkiye both experienced declines in renewable output, largely due to weaker wind conditions. Greece also saw a net reduction in renewable generation, as a significant drop in wind output outweighed gains in solar.
The data highlights a critical challenge for SEE markets: while renewable capacity is expanding, its contribution to system stability remains inconsistent. Solar generation provides predictable daytime output, but wind variability continues to introduce uncertainty into supply balances.
This dynamic has important implications for price formation. During periods of strong solar output, daytime prices can soften, but the absence of consistent wind generation limits the duration and extent of these effects. As a result, evening peak prices remain elevated, particularly when gas-fired generation sets the marginal price.
The growing role of solar also underscores the increasing importance of flexibility assets, including battery storage and demand response mechanisms. As solar penetration rises, intraday price spreads are expected to widen, creating opportunities for arbitrage but also increasing system complexity.
