Week 18 SEE power markets: demand softens, renewables swing pricing and deepen intraday volatility

Week 18 electricity market data across Southeast Europe pointed to a system moving further into a high-volatility spring transition—one where renewable intermittency and balancing needs are increasingly shaping prices more than baseload generation. Even as seasonal demand softened and some wholesale prices eased, the underlying signals showed intensifying intraday volatility, wider renewable-driven pricing spreads, and greater structural reliance on flexibility across national systems.

Demand falls across most major systems

Regional electricity demand declined by -2.82% week-on-week to 14,558.6 GWh, reflecting softer industrial activity, milder weather conditions, and lower heating-related consumption. Italy recorded the largest contraction among major systems at -5.06%, while Hungary fell by -6.21%. Greece and Romania both posted moderate declines, while Türkiye remained relatively stable with only a -0.82% reduction. Serbia’s electricity demand dropped by -3.57%, and Croatia by -4.72%.

Headline prices ease unevenly as fragmentation widens

Wholesale prices did not move in lockstep with demand. Greece and Bulgaria saw moderate price declines of approximately -5%, while Hungary eased by -3.21%. Italy was almost unchanged at structurally elevated levels, and Romania edged higher by +0.60%, suggesting localized tightening despite softer overall consumption.

The sharpest divergence came in Serbia and Croatia, where electricity prices rose by +7.15% and +7.90%, respectively—counter to the broader regional easing pattern.

Renewables rebound lifts some markets—but performance diverges

The main driver behind regional easing was a rebound in variable renewable energy output across SEE, which increased by 11.1% week-on-week to 3,459.6 GWh, led primarily by wind recovery. Wind generation rose by 24.7%, while solar production was broadly stable at +1.1%.

Türkiye emerged as the key stabilizer during the week: wind generation there nearly doubled (+98.3%), and total renewable production rose by an exceptional 69.3%. Greece also delivered a strong renewable rebound, with combined wind and solar generation rising significantly—solar up 26.5% and wind up 17.1%.

Yet renewable performance remained highly asymmetric across the region. Serbia saw one of the sharpest deteriorations, with total variable renewable generation falling by -40.4% due largely to weaker wind conditions; Bulgaria declined by -22.3%. Romania and Croatia recorded more moderate renewable weakness.

This divergence helped explain why certain markets moved against the regional trend: where renewables underperformed, systems required greater thermal dispatch and balancing imports—raising marginal price pressure even as demand fell.

Intraday curves show negative midday prices and steep evening ramps

The hourly structure delivered one of Week 18’s clearest market signals: extremely deep midday collapses followed by steep evening ramps. Several systems briefly entered negative-price territory during solar-heavy midday hours before rebounding into evening peaks above €200/MWh.

The widening intraday spread is becoming a defining feature of the SEE transition as rising solar penetration meets insufficient storage deployment. During daylight hours, abundant solar output pushes prices sharply lower; when solar output declines in late afternoon, thermal generation rapidly regains marginal pricing control—producing aggressive evening spikes.

Flexibility assets gain economic value

These dynamics increasingly favor flexible resources rather than purely baseload capacity. Battery storage systems, pumped hydro modernization, fast-response gas units, ancillary services, balancing reserves, and cross-border trading capabilities are becoming structurally more valuable across Southeast Europe.

Hydrology provides uneven resilience; thermal output contracts sharply

Hydropower production remained relatively stable overall, declining only -1.57% to 3,739.5 GWh, but with substantial country-level divergence. Croatia posted a hydro rebound of +132.2%, while Serbia increased hydro generation by nearly 20%. Greece also recorded modest growth; Bulgaria suffered a severe decline of -33.4%, while Türkiye and Romania weakened as well.

Hydrology remains critical for SEE balancing because hydro continues acting as the primary flexibility buffer for intermittent wind and solar output—so countries with stronger hydro positions demonstrated better resilience against renewable swings during the week.

Thermal generation fell sharply across the region to 3,527.8 GWh (-9.66% week-on-week). Coal/lignite output declined by -6.5%, while gas-fired generation fell by -12.6%. Türkiye recorded the largest thermal contraction at -19%, while Hungary also reduced thermal production materially.

Greece showed an internal fuel-switching pattern: lignite surged by +76.8%, while gas-fired generation dropped by -22.4%, indicating tactical displacement of expensive gas with domestic lignite capacity during peak balancing periods.

Romania moved against the regional trend by increasing gas-fired generation (+57.1%), pointing to a tighter domestic supply-demand balance and greater reliance on dispatchable thermal capacity for stability during volatile renewable cycles. Italy also slightly increased thermal output despite softer overall demand.

Cross-border flows shift as balancing becomes more regional

Cross-border electricity flows changed materially during Week 18: net imports across Southeast Europe declined by -12.8% to 1,079.5 GWh on stronger domestic renewable production and weaker demand.

Greece made the biggest transition from near-balance into net exports of approximately -109.7 GWh; Serbia reduced net imports by almost 69%; Romania and Hungary also lowered external dependency; Bulgaria remained a net exporter though export volumes fell materially; Türkiye slightly reduced its export position as improved renewables eased domestic balancing needs.

The scheduled flow picture underscores that SEE is no longer operating as isolated national systems—balancing conditions increasingly depend on cross-border coordination such as renewable synchronization effects, congestion management, and regional dispatch optimization.

Southeast Europe remains exposed to broader European gas-linked pricing

A final signal from Week 18 was persistence of structurally high European electricity pricing despite temporary easing in parts of SEE itself: broader European markets moved higher over the same period rather than lower alongside Southeast Europe’s softer conditions.

France recorded a dramatic +63.39% weekly increase; Spain, Portugal, Slovakia, Slovenia, Poland, Germany, and Austria all posted substantial gains.

This divergence suggests that while SEE can benefit temporarily from supportive hydro or renewables within its own borders, it remains fundamentally exposed to broader European gas-linked marginal pricing mechanisms tied to TTF dynamics—and could see renewed upward pressure if TTF gas prices rise further amid Middle East geopolitical tensions.

Taken together, Week 18 reinforced that Southeast Europe is entering a flexibility-driven electricity market era: future evolution will depend not only on how quickly wind and solar capacity grows but on how rapidly balancing infrastructure—including storage modernization and cross-border operational tools—can scale alongside it.