The Southeast European power market is entering a new investment cycle following a period defined mainly by adding renewable capacity. The next phase will be shaped by flexibility assets including batteries, hydro optimisation, pumped storage, interconnectors, balancing markets, digital forecasting and demand-side response.
Week 23 reflected the transition in operating conditions across the region. Regional demand increased 8.2%, while variable renewables fell 8.9%. Wind output dropped 15.5%, thermal generation rose 24.5%, hydro generation increased 10.1%, and imports climbed 9.1%.
The mix of changes indicated a flexibility stress test rather than a single-factor supply shortage or renewable performance outcome. Balancing relied on hydro generation, thermal output and cross-border flows during the period.
Week 23 balancing requirements and system risks
The region’s ability to balance during Week 23 depended on hydro, thermal generation and cross-border flows. However, that balancing approach does not address the requirements of a decarbonising system.
Thermal generation introduces carbon and fuel risk into dispatch decisions. Hydro output depends on hydrology, while import volumes depend on neighbouring availability and interconnector capacity.
This combination points to an investment gap affecting how the system can respond to changing conditions across seasons and hours.
Batteries for short-duration shifting and ancillary services
Batteries are identified as the most immediate flexibility opportunity in the region. The evening price ramp supports storage economics by enabling charging during lower-price solar hours and discharging during peak periods.
Two-hour and four-hour battery systems can support multiple market functions including arbitrage, balancing and ancillary services. Co-located BESS can also improve the bankability of solar and wind projects.
This role links storage operation to both price movements and operational needs within power markets.
Pumped storage as long-duration flexibility
Pumped storage is positioned as the long-duration layer of flexibility for Southeast Europe. The region’s hydro geography provides potential for such projects.
Project delivery depends on long development timelines, permitting requirements, grid coordination and public-private financing structures. As solar penetration increases, long-duration storage is expected to become more valuable.
Interconnectors, spreads and market efficiency
Interconnectors form another investment theme alongside storage technologies. Persistent spreads between Italy, Greece, Hungary, Romania, Serbia, Bulgaria and Croatia indicate that transmission constraints continue to limit market efficiency.
Increasing cross-border capacity can reduce price fragmentation, improve security of supply and help monetise regional surplus through more effective trading conditions.
Digital forecasting and balancing-market optimisation
Digital infrastructure is described as a key component of flexibility delivery in Southeast Europe. Forecasting systems, SCADA integration, intraday trading platforms and balancing-market optimisation are expected to become essential.
Flexibility is framed as both physical and informational through improved forecasting of wind, solar, demand and congestion patterns. That forecasting capability is presented as having direct financial value for market participants.
Investment themes beyond generation assets
The investment outlook extends beyond generation capacity toward portfolios that can provide flexibility across market timeframes. The next energy assets in SEE are expected to include storage portfolios, flexibility platforms, grid equipment, forecasting services and balancing aggregators.
The same shift also encompasses hybrid renewable projects designed to combine generation with flexible capabilities. Utilities and developers moving early are described as being able to capture premium margins in these areas.
Elevated by energy.clarion.engineer
