April trading highlights structurally volatile power market signals across SEE

April trading in South East Europe has been defined by a sharp rise in intraday volatility, with Electricity.Trade’s hourly price curves pointing to unusually wide spreads between midday and evening hours. For market participants, the implication is clear: day-to-day risk is increasingly driven by fast-moving system transitions rather than slower-moving fundamentals.

Hungary’s negative pricing and rapid reversals

Hungary recorded the most pronounced volatility. Prices fell to -€500/MWh during solar peaks before rising above €275/MWh in evening hours. Electricity.Trade hourly tracking also shows reversals exceeding €200–300/MWh within the same day, underscoring how quickly conditions can flip as generation patterns change.

Regional oversupply signals appear to be becoming embedded

Similar dynamics were observed across Slovenia, Romania and Bulgaria. Electricity.Trade negative pricing alerts indicate that midday oversupply events are moving from occasional occurrences toward a more structural feature, particularly in areas with high solar penetration.

Why prices swing: solar surges, constrained storage and inflexible thermal output

The pattern is attributed to several interacting factors. Solar output exceeding 5 GW regionally is increasing midday supply pressure. At the same time, limited storage capacity—still below 100 MW of aggregated utility-scale battery energy storage systems in key markets—reduces the ability to shift excess generation. Inflexible thermal generation remaining online further limits how quickly supply can be adjusted downward when solar output is high.

As solar production declines after hour 16–17, Electricity.Trade balancing signals show sharp increases in import demand and thermal dispatch. That combination helps explain why steep evening price spikes follow periods of negative or near-negative pricing.

Serbia stands out due to congestion effects

Serbia’s price profile diverged from the broader regional pattern. Electricity.Trade congestion analytics suggest that restricted import capacity during peak hours amplified price increases, pushing SEEPEX toward €96–100/MWh even as neighbouring markets softened.

A market where positioning risk dominates

Taken together, the developments point to a structurally volatile market environment where intraday positioning increasingly shapes trading strategy. Negative pricing is no longer treated as an anomaly but as a recurring feature linked to solar-driven oversupply and constrained flexibility across parts of the region.