The South-East European electricity system is entering a period in which the pace of renewable penetration, the rigidity of transmission assets and the volatility of balancing markets collide with growing continental interdependence. The region sits between two gravitational forces: a European Union accelerating its market integration and flexibility requirements, and a Balkan electricity landscape still struggling with legacy infrastructure, hesitant investment cycles and fragmented operational rules. Between 2026 and 2030, the region will move into one of three structural trajectories, each with different consequences for price spreads, balancing scarcity, curtailment volumes and investor confidence. These trajectories are not theoretical exercises. They are already visible in the early dynamics tracked daily on platforms such as electricity.trade, where cross-border spreads, balancing discrepancies and repeated congestion patterns show the contours of the region’s possible futures.
What follows is a forward-looking analytical narrative, not presented as discrete bullet points but as three unfolding realities. Each scenario builds upon the physical behaviour of the grid, the political choices that shape it and the growing renewable wave whose scale is now irreversibly altering market fundamentals.
Scenario 1 — 2026–2030 as a decade of drift: renewable growth without structural reinforcement
Under the first trajectory, the region continues to install renewable capacity at a pace far exceeding transmission and balancing upgrades. Solar in Greece and Hungary scales rapidly, wind in Romania expands both onshore and offshore planning phases, and Bulgaria begins to see an acceleration of utility-scale solar projects, while Serbia and Croatia expand mixed portfolios. The generation profile becomes progressively more volatile, yet national grids remain largely unchanged. Interconnection projects discussed for years linger in preparatory phases. Domestic political cycles extend permitting delays. And balancing capacity additions remain minimal because flexible assets, from batteries to CCGTs, are slow to materialise.
In this world, renewable penetration rises sharply, but the system’s ability to absorb or transport this energy does not keep pace. The result is a region where surplus clean electricity floods nodes that cannot export it and evening deficits recur with increasing severity. The market begins to resemble a stretched fabric that holds under pressure but deforms in unpredictable ways.
Greece becomes the paradigmatic case. By 2027, Greek solar surpluses intensify to the point where midday curtailment becomes structurally embedded into the market, not as an operational anomaly but as a planning reality. Spreads visible on electricity.trade during these hours show steep downward price pressure, often decoupling Greece from Bulgaria by margins reflecting transmission saturation rather than demand fundamentals. When evening ramps arrive, Greece reverses position and becomes one of the largest buyers of upward balancing energy in the region, pulling power from Bulgaria, North Macedonia and Albania and reinforcing evening price spikes that ripple north through Serbia and Romania.
Romania faces a parallel challenge. Dobrogea wind expands, offshore planning accelerates and onshore repowering introduces greater output variability. Yet export capability into Hungary remains constrained. Even if modest upgrades occur, they lag behind renewable growth. As wind surges in 2027–2028, Romania increasingly experiences congestion-induced price collapses at midday, particularly during strong wind events. Those observing Romanian intraday behaviour on electricity.trade begin to recognise a recognisable signature of the “Dobrogea trap”: sudden surges of available generation met with insufficient ability to exit the bidding zone, followed by sharp downward pricing patterns detached from regional averages. Romania continues exporting structurally to Bulgaria, but northbound constraints limit economic stabilisation.
Hungary’s position becomes increasingly precarious. With solar exceeding winter midday load and storage lagging behind, the system oscillates between daytime surplus and evening scarcity. Balancing prices become more volatile, and spreads between HU–RO and HU–SRB widen during balancing deficit hours. Traders see Hungarian volatility become a consistent feature on electricity.trade, where Hungarian hourly prices respond violently to even minor disruptions in neighbouring systems. The country becomes more dependent on imports during ramps but less capable of exporting surpluses efficiently during peaks.
Bulgaria, positioned between Greek surpluses and Romanian variability, becomes the unwilling median node of the regional system. Bulgarian dispatchers increasingly face two opposing pressures: Greek solar surges pushing north and Romanian balancing scarcity pulling southward. When both occur simultaneously, Bulgaria’s system becomes strained to the point that redispatch and balancing actions rise significantly. The price behaviour on electricity.trade reflects this dual exposure: moments where Bulgaria moves in lockstep with Greece for hours, only to snap back into alignment with Romania when northern conditions dominate.
Serbia, as the central transit and balancing corridor, suffers the most under this scenario. Its internal grid is forced to absorb increasing volatility coming from two directions. Southbound flows from Romania and Bulgaria clash with northbound needs during evening ramps, and Serbia lacks the flexible assets to moderate these shocks. Without access to a harmonised regional balancing pool, Serbia experiences local price deviations that ripple into Bosnia, Montenegro and occasionally North Macedonia. Traders monitoring SEE hourly spreads recognise Serbia not as a price-maker but as a volatility amplifier under stress.
By 2028–2030, curtailment becomes one of the defining features of SEE electricity. Investor risk premiums rise. Banks demand greater guarantees. Renewable developers incorporate curtailment assumptions into financial models. The region becomes known for its renewable abundance and structural inability to monetise it effectively. Energy remains clean but not valuable.
Scenario 2 — The congested transition: interconnections improve, but too slowly to fully stabilise the system
In the second scenario, the region embarks on a moderate acceleration of interconnection improvements between 2026 and 2030. The HU–RO interface undergoes phased upgrading. Bulgaria progresses on northern and southern interconnection reinforcements. Serbia invests in some internal north–south corridors. Greece stabilises some of its export pathways. And the Montenegro–Italy link finally gains more predictable utilisation. Yet balancing resources do not grow at the same pace, and storage remains insufficient. As a result, the system becomes more interconnected but not necessarily more stable. The region learns the hard way that interconnections alone cannot compensate for the absence of fast-acting flexible assets.
Still, improvements matter. On electricity.trade, spreads narrow at certain borders. HU–RO begins to behave more coherently during non-extreme hours. Greek surpluses occasionally find more room northward. Romanian exports increase during moderate wind events. Serbia’s system stabilises marginally because southbound and northbound flows gain additional routing alternatives. Bulgaria finds that its dual exposure, while still significant, becomes easier to manage during transitional hours.
Yet the region remains vulnerable to volatility during extreme renewable cycles. When Greek solar peaks, export capability improves but not enough to avoid curtailment. Romania still hits bottlenecks during massive wind surges. Bulgaria sees its mitigating role become more manageable but far from resolved. Hungary continues to oscillate between surplus and deficit because internal flexibility does not match solar expansion.
Balancing remains the structural weakness of SEE. During evening ramps, the region still requires substantial upward balancing energy. Price spikes remain frequent, even if less severe. Traders on electricity.trade notice spreads narrowing during moderate hours but expanding dramatically during scarcity events. SEE continues to behave as a volatility-prone region where interconnections help but do not fundamentally solve deeper structural issues.
Curtailment falls slightly, but remains economically significant. Price-cannibalisation persists, though softened. Renewables become more manageable, but still subject to risk parameters that complicate financing.
This scenario yields modest progress but entrenches SEE as a semi-integrated region — one that can no longer be described as “underconnected,” yet still lacking the systemic flexibility required to operate as a mature renewable-based electricity system.
Scenario 3 — Full integration: SEE becomes a stabilised, flexible, export-oriented renewable engine
The third scenario requires political will and unprecedented investment but is technologically feasible. Between 2026 and 2030, the region accelerates interconnection reinforcement to a level where major bottlenecks are resolved. Greece completes significant northbound upgrades. Romania connects Dobrogea more meaningfully to Hungary. Serbia’s north–south backbone is rebuilt and expanded. Bulgaria increases its bidirectional capacities and strengthens its internal grid. Croatia modernises coastal export corridors. And Montenegro’s HVDC link becomes fully integrated into regional dispatch.
Simultaneously, each country invests heavily in flexibility assets. Greece deploys utility-scale batteries at solar hubs, combined with new CCGT capacity designed for daily modulation. Romania develops pumped hydro modernisation and hybrid RES-plus-storage platforms. Bulgaria expands its hydro flexibility while enabling cross-zonal balancing activation. Serbia introduces gas flexibility, storage clusters and a more dynamic operational regime. Hungary invests in dispatchable gas units and battery projects co-located with solar. Montenegro leverages hydro as a balancing export resource.
Under this scenario, curtailment collapses from structural to marginal. Price-cannibalisation softens significantly. Renewable projects achieve more stable revenue profiles. SEE transforms from a fragmented region into a renewable export engine integrated into European balancing markets. On platforms like electricity.trade, spreads flatten, volatility normalises, and SEE’s bidding zones begin to converge with Central European behaviour except during extreme shocks.
This scenario enables SEE to become a strategic provider of flexible renewable power to the continent. Greece becomes Europe’s Mediterranean solar engine. Romania becomes a major wind player. Bulgaria becomes the stabiliser between south and north. Serbia transitions from volatility amplifier to regional coordinator. Hungary becomes a balanced solar-exporting node. Montenegro becomes the balancing corridor for Italy. Croatia supports Adriatic flows and seasonal hydro regulation.
The region moves from a reactive balancing culture to a proactive, market-driven flexibility system. Investors regain confidence. EU integration accelerates. SEE becomes not the edge of Europe’s energy transition but one of its core pillars.
Which scenario is most likely?
As of early signals in 2025, the region is positioned somewhere between Scenario 1 and Scenario 2. Renewable growth is accelerating faster than system reinforcement. Interconnections remain partially upgraded. Flexibility remains insufficient. Balancing markets remain fragmented. Price-cannibalisation and curtailment increase. Spreads observed on electricity.trade still show the characteristic “SEE pattern”: narrow alignment during calm hours, wide divergence under stress.
Scenario 3 requires political courage.
But it is the only future in which SEE becomes economically resilient rather than structurally volatile.
What will define SEE’s path between 2026 and 2030?
Three forces:
- the speed of interconnection reinforcement
- the scale of flexibility deployment
- the depth of regional balancing integration
If interconnections expand but flexibility stagnates, SEE lands in Scenario 2.
If neither improves, SEE drifts toward Scenario 1.
If both accelerate, SEE transforms into Scenario 3 — a stabilised, export-capable, renewable-dominant energy region.
Between now and 2030, the region must choose whether volatility becomes a permanent condition or a transitional phase.
The tools exist. The resources exist. The markets exist.
What remains uncertain is whether SEE will build the invisible infrastructure required to turn renewable abundance into economic stability.
If it does, electricity.trade charts of the late 2020s will show a region finally converging with Europe.
If it does not, those same charts will continue to reveal a market where abundance produces volatility rather than value.
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