Traders Take Greek Gas Route

Traders booked around 46% of the available export capacity at Sidirokastro, the main gas crossing between Greece and Bulgaria, in July's capacity auctions. Some of those bookings run as far as 2040/41 (Serbia Energy, News247). For once, the Vertical Gas Corridor has more than political speeches behind it. Traders are putting money on a route meant to move LNG from Greek terminals up through the Balkans and into Central Europe. Whether that route makes commercial sense at every border is still the test.

Every border is a toll booth

The corridor is not a single pipe. LNG tankers arrive at Revithoussa, near Athens, or at Alexandroupolis in northern Greece. The liquid gas is turned back into gas and fed into the Greek network. From there it crosses into Bulgaria through two border points, moves through Romanian pipelines, and partly reverses infrastructure that used to carry Russian gas southwards, towards Hungary, Slovakia, Moldova and Ukraine (Powergame, DW România).

Europe's gas grid does not work like a free-flowing motorway. At each national border, a trader must reserve entry and exit capacity, pay the transmission tariff, and comply with balancing rules, meaning the daily duty to match the gas put into the system with the gas taken out. The corridor only works if capacity is booked across all the necessary links at the same time. One missing border booking can break the whole route.

The July bookings happened because tariffs fell. After cuts on the Romanian section, the cost of moving gas from Greece to Ukraine dropped from €9.39 per megawatt-hour to roughly €5.85 (Euro2day). That was the price signal traders needed.

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 three times its volume a year earlier (Iefimerida). At the latest Alexandroupolis capacity auction, all capacity on offer was sold, with buyers paying above the reserve price because access was limited (BankingNews).

Greece gets transit fees, terminal revenue and more weight in regional supply negotiations. Bulgaria gets a route that bypasses its problematic fixed-fee contract with Turkey's Botaş for LNG access, where critics said only 10–20% of the contracted capacity was actually being used (Fakti).

For Malta, the logic is familiar even if the geography is not. Small energy systems live with the cost of limited routes and limited bargaining power. A new supply corridor is never just infrastructure; it changes who has options, who pays for access, and who is left exposed when prices move.

The competition the corridor has to beat

Romania is the corridor's hinge, but also its possible competitor. It carries transit gas today. 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 have less need for LNG routed through Greece.

Russian gas has not gone away. According to ACER, the EU agency for energy regulators, it still made up about 12% of EU consumption in January-May 2026. Pipeline imports were up 7% and LNG imports up 11% year-on-year (InvestEnergy). For countries such as Slovakia, where energy-intensive industry depends on affordable gas, the question is whether Greek-routed LNG can beat the remaining Russian-linked contracts on price (Energie-portal).

The wider supply picture is tightening. 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, showing that the route is commercially live for at least one small buyer (Moldova1).

The July bookings show traders will pay for this corridor when the tariff structure works. The route reduces single-supplier risk for a region that has felt Russian leverage directly. But there is still no public record showing capacity booked simultaneously across every border from Greece to the final destinations. As with any corridor, the weakest link still decides whether the gas actually arrives.