As the EU Carbon Border Adjustment Mechanism changes how carbon costs are priced at the border, traders across Southeast Europe are increasingly treating electricity routing as a compliance problem rather than only a market-efficiency exercise. Evidence from the first quarter of 2026 points to a measurable break with earlier corridor patterns that relied on the Western Balkans as a transit bridge between EU systems. The shift is not confined to schedules or price spreads; it is showing up in how physical flows and commercial expectations diverge across interconnectors.
CBAM compliance risk hits transit-based trading
For years, the Western Balkans operated as a critical transit zone within the broader Southeast European grid, linking EU systems through multi-leg arbitrage strategies. Trading routes such as Hungary–Serbia–Bulgaria and Croatia–Serbia–Romania were central to how market participants optimized flows across price differentials. Under CBAM pressure, uncertainty over how electricity transiting through non-EU countries should be treated has reduced the attractiveness of these corridors for intra-EU trade.
In Q1 2026, commercially scheduled cross-border exchanges between the Western Balkans and the EU fell by about 25% compared with the same period in 2025. The decline was asymmetric: EU imports into the Western Balkans dropped by 40.7%, while flows in the opposite direction weakened more moderately. The result was a change in net trade position, with the Western Balkans moving from net importer to net exporter by approximately 1.35 TWh, driven primarily by collapsing imports rather than a surge in exports.
New “carbon-efficient” routing emerges
With transit-based strategies becoming harder to justify under regulatory ambiguity, electricity is increasingly rerouted through alternatives that remain within EU jurisdiction or involve low-emission supply. This is translating into a new geography of power flows where carbon exposure can outweigh traditional considerations such as shortest paths or purely economic dispatch. The practical effect is that interconnector value is starting to reflect regulatory risk and carbon costs more directly than capacity constraints alone.
One of the clearest beneficiaries of this reconfiguration is Albania, whose hydro-dominated generation mix is associated with a default emission factor effectively equal to zero in the CBAM context described by industry analysis. In Q1 2026, Albania increased scheduled exports across borders, including flows to Greece, Kosovo, and Montenegro. Net redistribution amounted to roughly 1.2 TWh versus the same quarter of 2025.
Hydro surplus flows via Greece into EU markets
The Albanian surplus did not stay local; it moved through Greece and onward into EU markets including Bulgaria and Italy. Greece emerged as an intermediary as hydro generation rose substantially, with flows from Albania to Greece increasing markedly before electricity moved northward and westward into the broader EU system. This south-to-north corridor—anchored by low-carbon generation—has gained prominence as an alternative to traditional transit routes associated with coal-heavy systems.
At the same time, intra-regional trading within the Western Balkans intensified as EU-facing exchanges became more constrained. Markets turned inward, increasing trade among themselves as surplus generation—particularly hydro—found outlets closer to home. While this can support liquidity and price discovery inside WB6 markets, it does not fully replace access to higher-priced EU demand.
Interconnector performance shows compliance-driven rerouting
The corridor shift is also visible in specific interconnector outcomes, illustrating how CBAM-related cost pressures can override market spreads. The Montenegro–Italy submarine cable provides a notable example: despite offering a direct link between a lower-priced WB6 market and a higher-priced EU market, utilization declined in Q1 2026. Scheduled flows from Montenegro to Italy fell by more than 2,100 MWh per day, while physical flows decreased by approximately 1,400 MWh per day.
Crucially, this happened even as the price spread between the two markets widened significantly, pointing to CBAM costs as an effective removal of the economic advantage of exporting along that corridor. More broadly, interconnector relevance appears increasingly tied to whether they connect low-carbon systems to EU demand rather than whether they simply capture price differentials.
Commercial schedules diverge from physical reality
The reconfiguration introduces operational complexity because commercial intent does not always match physical flow behavior in interconnected grids. Traders adjust schedules to minimize CBAM exposure, but electricity continues to move according to grid physics and network characteristics. As a result, increased scheduled exports along certain corridors may not be reflected proportionally in physical flows along those same routes.
An example cited in Q1 2026 data is that increased commercial exports from Albania to Greece were not fully mirrored by physical flows along that route; electricity continued moving through Montenegro and Bosnia and Herzegovina toward EU markets. This mismatch can create inefficiencies for transmission system operators, raising risks linked to congestion patterns, loop flows, and operational instability.
Implications for industry investment and trade compliance
For infrastructure planning, changing routing patterns raise questions about assumptions embedded in projects designed around stable arbitrage flows. Interconnectors that previously promised strong congestion revenues may face reduced utilization if traders continue prioritizing carbon exposure minimization over traditional corridor economics. Conversely, opportunities may emerge where new or existing pathways better align low-carbon supply with EU demand under CBAM-related constraints.
For importers and exporters operating under CBAM-linked compliance logic alongside EU ETS-aligned carbon pricing frameworks under the European Green Deal direction of travel, these developments underline how regulatory treatment can influence where value chains source electricity—not only what they buy or sell. While this reporting period reflects early observed shifts rather than a definitive end-state of implementation effects, it shows how quickly trade behavior can respond when transit risk becomes part of compliance decision-making.
Analytical synthesis: carbon exposure becomes a routing variable
Taken together, the Q1 2026 figures show a consistent pattern: reduced EU-to-Western Balkans imports alongside a move toward net export status for WB6 driven by import collapse; increased reliance on low-carbon supply sources such as hydro-dominant Albania; and corridor-level outcomes where interconnector utilization declines even when price spreads widen. The resulting system is one where carbon exposure considerations increasingly shape both commercial scheduling and physical network management challenges for operators.
Looking ahead, any restoration of Western Balkans corridor attractiveness would depend on clearer treatment of transit flows under CBAM conditions and adjustments that reduce emission-factor disparities between systems. Additional alignment could also come from developing carbon pricing mechanisms within the Western Balkans to reduce asymmetry between EU and non-EU markets—factors that would directly affect how importers assess compliance risk when selecting routes for electricity procurement.