Traders book 46% of Greek gas corridor

In July capacity auctions, traders booked around 46% of available export capacity at Sidirokastro, the main Greece-Bulgaria gas border crossing, with some reservations stretching to 2040/41 (Serbia Energy, News247). That is real money committed to the Vertical Gas Corridor, a chain of pipelines designed to move LNG from Greek import terminals northward through the Balkans into Central Europe. The route has produced its first genuine commercial signal. Whether the economics hold across every border is another question.

Every border is a toll booth

The corridor is not one pipeline. LNG tankers dock at Revithoussa, near Athens, or at Alexandroupolis in northern Greece. The liquid is reheated into gas and enters the Greek grid. It crosses into Bulgaria through two border points, then continues through Romanian pipelines, partly reversing infrastructure that once carried Russian gas southward, toward Hungary, Slovakia, Moldova and Ukraine (Powergame, DW România).

Europe's gas grid does not work like a motorway. At every national border, a trader must book entry and exit capacity, pay the local transmission tariff, and meet balancing rules (the daily obligation to match gas put into the system with gas taken out). The corridor functions only when capacity is booked simultaneously across every leg. Miss one border and the route breaks.

Tariff cuts made the July bookings possible. After reductions on the Romanian section, the cost of moving gas from Greece to Ukraine fell from €9.39 per megawatt-hour to roughly €5.85 (Euro2day). That brought the price low enough for traders to commit.

Greek terminals are filling up

In the first half of 2026, Revithoussa processed 18.61 TWh of gas, while Alexandroupolis handled 3.46 TWh, more than triple its volume from a year earlier (Iefimerida). At the latest Alexandroupolis capacity auction, all offered capacity sold out, with buyers paying above the reserve price because access was limited (BankingNews).

Greece gains transit fees, terminal revenue and leverage in regional supply talks. Bulgaria gains a route that sidesteps its troubled fixed-fee contract with Turkey's Botaş for LNG access, where critics argued only 10–20% of contracted capacity was actually used (Fakti).

The competition the corridor has to beat

Romania is the corridor's pivot and its potential rival. It carries transit gas today, but its Neptun Deep Black Sea field, with estimated resources of around 100 billion cubic metres, could start production around 2027 (HotNews). If Romanian domestic gas reaches Central European markets at scale, buyers may not need LNG routed through Greece.

Russian gas has not disappeared either. According to ACER (the EU's energy regulators' agency), it still accounted for about 12% of EU consumption in January–May 2026, with pipeline imports up 7% and LNG imports up 11% year-on-year (InvestEnergy). For countries like Slovakia, where energy-intensive industry depends on affordable gas, the question is whether Greek-routed LNG can compete with remaining Russian-linked contracts on price (Energie-portal).

The wider supply picture adds pressure. The EU needs LNG imports roughly 13% above 2025 levels to refill storage to 90% before winter (Euronews). Moldova's state energy company Energocom has already reserved capacity at the Romania-Moldova border, a sign the route is commercially live for at least one small buyer (Moldova1).

The July bookings prove traders will pay to use this route when the price is right. The corridor cuts single-supplier risk for a region that felt Russia's leverage directly. But no public record yet shows simultaneously booked capacity across every border from Greece to final destinations. The weakest link in the chain still decides whether the gas arrives.