Transgaz sells more gas than it buys for balancing, ACER says

Romania’s gas transmission system operator continued to sell more gas than it bought for system balancing in the 2024–2025 gas year, although the difference between the two types of intervention narrowed compared with the previous year. The finding appears in the report published on October 23, 2026, by ACER, the European Union Agency for the Cooperation of Energy Regulators, which recommends examining the mechanisms in which this pattern persists.

In brief

In Romania, sales remained predominant in the volumes traded by the operator to balance the network in 2024–2025, but to a lesser extent than in the previous year. The indicator does not measure the country’s exports.

In the European zones with comparable data, the share of days with operator interventions fell, on average, from 36% to 32%. The volumes of these interventions decreased from 0.44% to 0.32% of the gas transported.

Suppliers and traders must correct their own differences between the gas injected and the gas withdrawn. The operator’s intervention supplements this mechanism when necessary for the network to function.

Predominant sales alone do not prove a deficiency. ACER recommends checking access to information, trading possibilities, and incentives to avoid imbalances.

Balancing costs and revenues are settled with network users through a neutrality mechanism. The report does not establish any change to tariffs or bills in Romania.

Balancing takes place when the quantities of gas injected into a network do not match those withdrawn. Commercial responsibility lies primarily with suppliers, traders, and other network users, who can adjust their positions by buying or selling gas. The transmission system operator also intervenes to keep the system within the limits required for operation. In Romania, this role falls to Transgaz.

Therefore, the predominance of sales described by ACER concerns only the gas traded by the operator in these interventions. It does not show whether Romania is a net exporter or whether national production exceeds consumption. In the previous gas year, 2023–2024, more than 80% of the volumes in the Romanian operator’s balancing operations came from sales, according to ACER’s 2025 report. The new edition confirms the trend, but describes it as less pronounced.

The data concern the period October 1, 2024–September 30, 2025. The report published now therefore assesses a completed gas year, not current operations in the autumn of 2026. ACER used data provided by the European Network of Transmission System Operators, ENTSOG, supplemented and validated together with national regulatory authorities.

At European level, the share of days on which operators intervened for balancing fell, on average, from 36% in 2023–2024 to 32% in 2024–2025, in the zones for which comparable series are available. In the same group of zones, the volumes bought and sold for these actions fell from 0.44% to 0.32% of the physical market volume. These figures do not cover all European zones, as comparable data for the entire period are missing for some of them.

However, the decline in interventions does not translate into an equally significant reduction in users’ imbalances. Overall, these decreased only moderately, and the trend was not uniform across zones. ACER warns that an operator that intervenes little does not automatically indicate an efficient market, since balance may also depend on the system’s physical resources, not only on participants’ transactions.

To compare the direction of interventions, the agency considers zones relatively balanced when purchases account for between 40% and 60% of the total volumes of the operator’s actions. Romania remains in the category where sales predominate. The strongest sales-oriented patterns are found in Bulgaria and Lithuania, where purchases accounted for only 3% and 11% of volumes, respectively.

The direction can change substantially from one year to the next. In Italy, the share of purchases fell from 90% to 48%, reaching the range considered balanced. At the Greece–Bulgaria interconnector, purchases accounted for 93%, but the operator intervened on only 11 days. Such a low number of interventions limits conclusions about persistent behavior.

For Romania, the relevant question is whether participants have the information, access to flexible gas, and trading opportunities needed to correct their positions before Transgaz intervenes. ACER recommends conducting a deeper analysis when purchases or sales strongly and repeatedly predominate. The indicator alone does not establish the cause and does not constitute a finding that the operator breached the rules.

Market size also affects comparisons. The physical volume used by ACER includes both gas delivered to domestic consumers and gas crossing the network toward other systems. Following the cessation of Russian gas transit through Ukraine in January 2025, supply shifted more toward the center and east from western and northern Europe, along longer routes. The replenishment of storage facilities also supported transport, so physical flows recovered faster than consumption. A smaller share of balancing in these flows must also be viewed in this context.

The cost of the mechanism is distinct from the frequency of interventions. European rules provide that the operator must neither gain nor lose from balancing activity. Revenues and costs are settled with network users through the neutrality mechanism, under the conditions approved by the regulatory authority. The regulation allows the exclusion of costs that it considers to have been incurred inefficiently.

A surplus in the neutrality account should be returned or credited to users, while a deficit entails costs to be recovered. This is not, however, a calculation of household bills. ACER also points out that some costs borne by participants, for example those generated by constraints on physical flows, may remain outside this account. Conclusions about the efficiency of a regime therefore require more than reading a single balance.

The agency recommends that national authorities periodically assess commercial incentives, the quality of information, and balancing costs. If the rules are revised, consultation with participants and regional cooperation can help identify better solutions. For Romania, the report provides a reason for this assessment, without ordering a tariff change and without quantifying an effect on consumers’ bills.

https://2eu.brussels/ro/news/operatorii-europeni-intervin-mai-rar-pentru-echilibrarea-gazelor-dar-romania-mentine-o-piata-orientata-spre-vanzari