Cross-border electricity trading in Southeast Europe declined sharply in the week to September 13, limiting the region’s ability to balance supply and demand between national markets and contributing to higher wholesale prices in most countries.
Aggregate net electricity flows fell 23.2% week on week to 0.94 TWh, down from 1.22 TWh in the previous period. The decline came alongside a 7% reduction in wind and solar generation and lower thermal output in Greece, Serbia, Croatia and Türkiye.
Romania recorded the largest reduction in net imports, which fell by almost 50% to 74.54 GWh. The decline was supported by an almost 80% increase in wind generation and a 10.6% rise in thermal output, reducing the country’s reliance on electricity from neighbouring markets.
Hungary reduced its net imports by 12.5%, while Croatia recorded a 9.7% decline. Lower import volumes, however, did not translate into weaker wholesale prices. Croatia’s weekly average price increased 8.5% to €176.34/MWh, while Hungary’s rose 4.6% to €177.31/MWh as both markets became more reliant on domestic generation during periods of weaker renewable availability.
Bulgaria moved against the regional trend, with net exports increasing 38% to 274.67 GWh. Higher thermal generation, combined with a modest increase in variable renewable output, enabled the country to supply neighbouring markets despite a significant decline in hydropower generation.
Greece also increased its net export position, with exports rising from 79.2 GWh to 91.93 GWh. The increase was driven primarily by a 7.5% decline in domestic electricity demand, which reduced the amount of generation required to meet consumption within the country.
Serbia recorded a marginal increase in exports as higher hydropower generation and weaker domestic consumption offset lower thermal output. Despite this, the Serbian wholesale electricity price increased 11.1%, marking the strongest weekly price increase among the monitored Southeast European markets.
The decline in cross-border trading highlights the growing importance of regional interconnectors linking the Western Balkans with Greece, Bulgaria, Romania, Hungary and Croatia. When renewable generation declines across several markets at the same time, available transmission capacity becomes an increasingly important component of the regional supply balance.
Reduced cross-border flows can therefore leave individual markets more exposed to domestic generation costs and contribute to wider price differences between neighbouring countries, particularly when renewable output is volatile and conventional generation remains constrained.
Elevated by Virtu.Energy
