Central and Southeast European power prices swung within a single week, moving from scarcity levels close to €200/MWh to zero and negative pricing during Sunday’s solar peak. Evening prices still rose above €225/MWh, indicating a mismatch between daytime renewable output and post-sunset supply conditions. The changes were reflected across multiple national day-ahead markets.
SEEPEX reversal across the Aug. 31 to Sept. 6 trading week
Serbia’s SEEPEX market recorded the reversal, rising to €184.92/MWh on Sept. 3 before falling to €60.19/MWh on Sept. 6. The shift was linked to firmer renewable generation and lower weekend demand replacing nuclear-driven scarcity with daytime oversupply. The week also showed a sharp decline in prices after the midweek peak.
SEEPEX day-ahead baseload increased from €132.21/MWh on Aug. 31 to €166.25/MWh on Sept. 1, €173/MWh on Sept. 2 and €184.92/MWh on Sept. 3. Prices then dropped to €149.76/MWh on Sept. 4, €114.47/MWh on Sept. 5 and €60.19/MWh on Sunday, representing a decline of roughly two-thirds from Thursday’s peak.
Tight midweek conditions in Hungary and Romania
Hungary and Romania remained tighter during the middle of the week, with prices near €197/MWh at the midweek peak. Evening hours stayed above €275/MWh, indicating that higher renewable output did not remove scarcity after sunset. For Sept. 3 delivery, Hungary cleared at around €196.57/MWh, while Romania cleared at around €196.82/MWh.
Bulgaria, Greece, Croatia and Slovenia were clustered mostly between €190 and €193/MWh for Sept. 3 delivery, according to the reported levels. Romania’s continued loss of nuclear generation was cited as a factor behind the tighter pricing conditions in the period covered by the week’s data.
Nuclear outages, Cernavodă unavailability and evening pressure
The reported tightening in Central and Southeast European markets during the first half of the week was attributed to firm-generation constraints, nuclear outages and higher weekday demand. As renewable output rose and weekend consumption fell, prices moved sharply lower into Sunday’s solar period.
With Cernavodă unavailable, the system relied more heavily on imports, fossil-fuel generation, hydro and renewables, increasing pressure on neighbouring Hungary and Bulgaria . The impact was particularly visible during evening hours, when Hungarian power reached about €276.5/MWh during the Sept. 1 evening peak.
Romania climbed to around €283/MWh during the same evening period referenced in the report . These levels were presented alongside the later shift into negative or near-zero pricing during daylight hours as solar output increased.
Geographical fragmentation: Germany vs Central SEE spreads
A second major feature of the week was widening geographical fragmentation across markets. Germany became significantly cheaper than Central SEE markets even as west-to-east electricity flows increased . For Sept. 3 delivery, German day-ahead baseload fell to around €133.62/MWh, leaving Hungary almost €63/MWh higher.
The divergence widened further a day later, when Germany fell to about €88.95/MWh, while Hungary remained at €179.78/MWh. That produced a spread of almost €91/MWh, with the premium persisting into subsequent trading intervals described in the report . The reported interpretation tied this pattern to transmission congestion rather than an overall lack of electricity.
Sundays’ solar peak: negative prices alongside high evening values
The end of the week saw rising solar production and lower weekend demand reverse market conditions into Sunday’s solar period . Hungary, Romania, Slovenia and Croatia recorded negative prices during that period, while Bulgaria and Greece traded around zero for several consecutive daylight hours.
In Hungary, electricity fell to around -€1.5/MWh near 13:00 before rising to roughly €227.7/MWh at 20:00 . Romania followed a similar pattern, falling to around -€1/MWh, then climbing back toward €228/MWh in the evening . The reported move indicated that solar-driven oversupply became increasingly regional rather than confined to individual bidding zones.
Differing Serbia-Hungary dynamics through renewable availability changes
The report also highlighted that Serbia continued trading differently from the Central SEE core despite some convergence during midweek tightening . A discount toward Hungary narrowed briefly during tighter conditions but widened again as renewable availability increased.
The SEEPEX price moved from €184.92/MWh on Thursday to €60.19/MWh on Sunday, while Hungary remained structurally firmer over the same period . The volatility was described as reflecting rapid shifts in domestic generation, imports, cross-border schedules and network constraints affecting the Serbia-Hungary spread.
Divergent value signals for flexibility and cross-border capacity
The week’s outcomes were presented as reinforcing two market signals related to intraday spreads and geographical spreads . Wide intraday spreads were linked in the report with battery storage, reservoir hydro and demand response, while large geographical spreads were linked with interconnectors and transmission reinforcement.
The report also stated that average baseload prices could overstate what photovoltaic plants capture because their output is increasingly concentrated in the lowest-priced hours . By Sunday, several markets had effectively zero-value solar periods even though evening electricity exceeded €225/MWh.
The week ended with Southeast Europe showing both surplus and scarcity within the same market cycle: abundant renewable electricity during daytime alongside insufficient flexibility and transmission capacity for delivering it where it carried more value . This pattern was reflected across multiple national price profiles described over Aug. 31 through Sept. 6.
