Romania's Day-Ahead Market (PZU): How OPCOM Sets the Price of Electricity

PZU (Piața pentru Ziua Următoare), Romania’s day-ahead market, is the daily auction run by OPCOM in which generators, suppliers, traders and large consumers buy and sell electricity for every 15-minute interval of the following day. The resulting price is the benchmark for the price of power in the Romanian energy market: PPAs and Contract for Difference payments are built on it, and with a lag it feeds into retail tariffs. In September 2026 a megawatt-hour averaged EUR 176.14 on PZU, against EUR 95.55/MWh in April.

What PZU is and what OPCOM does

OPCOM defines the day-ahead market as a component of the wholesale electricity market in which firm trades are concluded for delivery on the next day. Participation is voluntary, but every participant must either hold balancing responsibility itself or have transferred it to another balance responsible party. OPCOM is the counterparty to every trade.

OPCOM, the Romanian electricity and natural gas market operator, was set up in August 2000 as a subsidiary of Transelectrica, which held 97.84% of its share capital at the end of 2025; the remaining 2.16% belongs to the state through the General Secretariat of the Government. Besides PZU, it runs the intraday market and the bilateral contract platforms, is the designated market operator for European market coupling and, since 2024, the counterparty for Contracts for Difference. About 40 TWh was contracted for delivery in 2025 on its electricity markets.

At the end of 2025, PZU had 235 registered participants, 203 of them active during the year, and traded 15,692 GWh in 2025. In the first nine months of 2026, monthly PZU volumes were equivalent to between 26.71% (June) and 33.30% (May) of forecast net consumption.

How the PZU auction works: timetable and 15-minute products

PZU is a closed auction held every calendar day. The trading system opens at 06:00 CET, available cross-border capacity is published at 10:30 and the order book for the next delivery day closes at 12:00 CET. Trade confirmations are published at 13:05, after which OPCOM sends the physical notifications to Transelectrica, the transmission system operator. The full timetable and participation rules are on OPCOM’s day-ahead market page.

Since 30 September 2025 (the first trading day, for delivery on 1 October), PZU has run on a 15-minute market time unit, together with the rest of European day-ahead coupling, so each delivery day now has 96 prices rather than 24. Participants can still bid in 15, 30 or 60-minute intervals and use block orders, linked across several consecutive intervals, which are accepted or rejected on the basis of the prices across all the intervals they cover. Bids are submitted in lei, while the coupling algorithm works in EUR/MWh at the National Bank of Romania rate for the trading day, which is why OPCOM’s reports carry prices in both currencies.

How the PZU price is set: marginal pricing

Sell orders are aggregated into a supply curve and buy orders into a demand curve. The market clearing price is the point where the two curves cross, within the limits of available interconnection capacity. Every trade in the Romanian bidding zone for that interval settles at this single price: a generator that offered cheaply receives the same price as the last, most expensive accepted offer.

The price is therefore set by the last unit needed to meet demand. When consumption is covered by sources with low variable costs, the price falls; when gas-fired plants or imports are needed, it rises to their cost. That is why hydro and nuclear availability, gas prices and midday solar output explain most of the price movements in Romania.

Price limits are harmonised across Europe, and the floor was lowered from EUR -500 to EUR -600/MWh from the 28 May 2026 trading session, after very low prices in several countries triggered the adjustment on 25 and 30 April.

Coupling with neighbouring markets (SDAC)

From 19 November 2014 to 16 June 2021, PZU was coupled with the Czech, Slovak and Hungarian markets. On 17 June 2021 it joined Single Day-Ahead Coupling (SDAC), the Bulgarian border followed on 27 October 2021, and since 8 June 2022 capacity on the borders of the Core region has been calculated on a flow basis. The common algorithm, Euphemia, sets prices in all coupled zones simultaneously while respecting network limits; the NEMO Committee describes how SDAC works.

If the interconnector between two zones is not congested, their prices are equal; once capacity runs out, the price in the importing zone stays higher than or equal to the price in the exporting zone. For investors, export limits matter directly: on a sunny midday with saturated interconnectors, surplus solar stays in the Romanian system and depresses the local price, a theme we examined in our analysis of imports and export capacity.

After PZU: the intraday market and balancing

On the intraday market, also run by OPCOM, continuous trading is possible until one hour before delivery, in 15 and 60-minute products. Each trade is concluded at the price of the existing order, so a single interval can have several prices. The intraday market has been coupled with Europe’s Single Intraday Coupling (SIDC) since 19 November 2019, and since 13 June 2024 it has also held three intraday auctions for each delivery day: at 15:00 and 22:00 CET on the previous day and at 10:00 CET on the delivery day. Romania’s borders were included in these auctions on 18 March 2025. The intraday market remains far smaller than PZU: in September 2026 it was equivalent to 3.69% of forecast net consumption.

Remaining deviations between what each participant notified and what it actually produced or consumed are settled on the balancing market, run by Transelectrica. The cost of imbalances falls on the balance responsible party, so participants close their positions as precisely as they can on PZU and intraday. For a battery, balancing and ancillary services are revenue streams separate from the spread between midday and evening prices.

Romanian electricity prices on PZU in 2026: the price per MWh

According to OPCOM’s monthly reports, the average price started 2026 at EUR 150.51/MWh in January, fell to EUR 95.55/MWh in April and rose to EUR 176.14/MWh in September, the highest monthly level of the year. The arithmetic average for 2025 was EUR 108.16/MWh, and September 2025 averaged EUR 97.05/MWh.

Month (2026)	Average (EUR/MWh)	Average (RON/MWh)	Peak, hours 9-20 (RON/MWh)	Off-peak (RON/MWh)
January	150.51	766.48	899.33	633.64
February	99.75	508.18	529.25	487.11
March	105.15	535.81	436.98	635.00
April	95.55	486.89	327.73	646.06
May	109.56	571.64	364.38	778.90
June	122.99	644.67	466.13	823.21
July	120.14	629.25	445.90	812.59
August	151.16	793.55	635.18	951.92
September	176.14	926.70	748.84	1,104.55

Source: OPCOM monthly market reports; arithmetic averages of the market clearing price. Peak covers hourly intervals 9-20 and off-peak intervals 1-8 and 21-24, as defined by OPCOM.

From March to September 2026, power in peak hours was cheaper than off-peak power in every month; in April, peak cost roughly half as much as off-peak. The main explanation is solar: with more than 7 GW installed, 3.9 GW of it on prosumer rooftops, midday is no longer the most expensive part of the day. In winter the relationship reverses.

The summer added a system-specific driver: nuclear output at Cernavodă was interrupted for more than a month while the Danube fell to its lowest level since 1996, squeezing hydro output and cooling water at the same time (see our analysis of Danube water levels and power hedging). Prices kept rising into October: in the week of 12 to 18 October 2026, OPCOM’s ROPEX_DAM_Base index stood at RON 1,283.95/MWh. The figures for the latest full month are in OPCOM’s September 2026 report, and the contract context is on our PPAs and electricity prices page.

Negative prices on PZU: when and why they occur

A negative price means that, in a given interval, the buyer is paid to take the power; legally, OPCOM treats such a trade as a service provided by the party receiving the energy, not as a sale of goods. It happens when supply, mostly solar, exceeds domestic demand and export capacity and some generators prefer to pay rather than cut output, for instance because shutting down and restarting a plant would cost more.

According to OPCOM’s weekly reports, in 23 of the 42 weeks reported up to 18 October 2026 at least one 15-minute interval cleared below zero. The first such week was 23 February to 1 March and the last 21 to 27 September, and the lowest price was RON -508.02/MWh, in the week of 20 to 26 April. At the other extreme, the highest 15-minute price of 2026 was RON 5,321/MWh, in the week of 29 June to 5 July. For storage, what matters is the spread between midday and evening, not the daily average (see our piece on negative power prices and BESS).

PZU and the electricity bill

The PZU price is not the price on a bill. A household bill adds transmission and distribution tariffs, system services, the cogeneration contribution, green certificates, excise duty and VAT to the energy component. Household electricity prices were capped until June 2025; since then, the price in the supply contract applies.

Nor do suppliers buy all their power on PZU; they contract a large share in advance. In September 2026, contracts traded on OPCOM’s PCCB-LE-flex platform for delivery in that month carried a weighted average price of EUR 114.07/MWh, while PZU averaged EUR 176.14/MWh. That is why a day-ahead price rise reaches bills gradually and only in part, and so does a fall. Industrial buyers can combine forward contracts and PPAs, options we compared in our article on a three-year power buying strategy.

PZU, PPAs and CfDs: the benchmark for investment

A PPA fixes the price for an agreed volume and profile, and its value to both sides depends on what the same energy would have earned on PZU in the same 15-minute intervals. That is why negotiations have shifted from annual volume to hourly profile, especially for buyers who must prove hourly supply for CBAM reporting (see our analysis of corporate PPAs and hourly matching).

Romania’s Contracts for Difference are tied directly to PZU. Under the framework contract published by OPCOM as CfD counterparty, the monthly reference price is the average PZU price in each settlement interval, weighted by the output of all CfD plants using the same technology, and is approved by decision of ANRE (Romanian Energy Regulatory Authority). The generator receives the difference between the strike price and the reference price on its own metered output sold on an organised market, and pays the difference back when the reference price exceeds the strike price. Two details matter: in intervals with a negative PZU price the difference payment is zero and those intervals are excluded from the reference price, and a plant that earns less in the market than its technology average is not compensated for the gap. The consolidated contract after Government Decision 1013/2025 is published by OPCOM. Round-two strike prices (an average of EUR 40.46/MWh for solar and EUR 73.8/MWh for wind, for 15 years) remain the reference for what new-build renewable power costs in Romania.

What PZU means for solar, wind and storage investors

For solar, the 2026 data show that the market average is not the price a plant earns. A solar plant sells precisely in the hours that, from March to September, were the cheapest, and in negative intervals its market revenue becomes a cost. Models should be built on 15-minute profiles rather than monthly averages, and co-located storage or a PPA that pays for profile changes both revenue and financing terms (see our Romania solar market page).

Wind produces more at night, in the evening and in winter, so its profile overlaps better with the expensive intervals of 2026. Its CfD strike prices, well above those for solar, reflect higher turbine, logistics and grid costs.

For storage, PZU and the intraday market offer the spread between midday and evening, and balancing and ancillary services add to revenue. Romania had 1,130 MWh of operational battery storage (599 MW) in April 2026, and the EUR 150 million Modernisation Fund call for standalone batteries is open until 30 October 2026 (see our energy storage page). As storage and interconnection are added, part of the spread will compress, so sizing and trading strategy matter as much as equipment.

Momentum Energy’s view

For us, PZU is the main benchmark for judging the value of a project. The 2026 data point in one direction: midday hours have become cheaper, evenings and cold months have stayed expensive, and the spread between them is now central to any business plan for solar, wind or storage.

We therefore recommend assessing new projects on 15-minute profiles, with scenarios for negative intervals and imbalance costs, and designing them from the start with storage or a contract that pays for profile. As an EPC contractor holding ANRE certifications for design, execution and testing, and with our energy trading activity in preparation, we help investors connect technical design to market reality through our services.

Sources and references

Organisations and documents cited in this article.

1. OPCOM: Piața pentru Ziua Următoare (descriere și program de tranzacționare)
2. OPCOM: Regulamentul PZU (Ordinul ANRE 82/2014, actualizat prin Ordinul 213/2020)
3. OPCOM: Raportul administratorilor pentru anul 2025
4. OPCOM: comunicat de presă, 21 august 2026 (OPEM și date despre OPCOM)
5. OPCOM: Raport de piață lunar, ianuarie 2026
6. OPCOM: Raport de piață lunar, februarie 2026
7. OPCOM: Raport de piață lunar, martie 2026
8. OPCOM: Raport de piață lunar, aprilie 2026
9. OPCOM: Raport de piață lunar, mai 2026
10. OPCOM: Raport de piață lunar, iunie 2026
11. OPCOM: Raport de piață lunar, iulie 2026
12. OPCOM: Raport de piață lunar, august 2026
13. OPCOM: Raport de piață lunar, septembrie 2026
14. OPCOM: Raport săptămânal, 23.02.2026-01.03.2026
15. OPCOM: Raport săptămânal, 20.04.2026-26.04.2026
16. OPCOM: Raport săptămânal, 29.06.2026-05.07.2026
17. OPCOM: Raport săptămânal, 21.09.2026-27.09.2026
18. OPCOM: Raport săptămânal, 12.10.2026-18.10.2026
19. NEMO Committee: Single Day-Ahead Coupling (SDAC)
20. SDAC Communication Note, 7 May 2026: Harmonised Minimum Clearing Price to Be Set to -600 EUR/MWh
21. SIDC: comunicat privind lansarea celui de-al doilea val, 28 noiembrie 2019 (OPCOM)
22. OPCOM: Contract CfD, formă consolidată după HG 1013/2025
23. IEA: Electricity and natural gas price cap and compensation scheme (extensions of OUG 27/2022)
24. Europa Liberă: Explainer, Tu știi ce conține factura ta la energie? (5 octombrie 2022)
25. ANRE (Romanian Energy Regulatory Authority)
26. Transelectrica (transmission system operator)
27. OPCOM (Romanian power exchange)
28. EU Modernisation Fund (European Commission, Climate Action)
29. National Bank of Romania (BNR)