Romania’s power price curve provides a clear warning against valuing generation or supply contracts against a single daily reference price. The country is increasingly experiencing extreme intraday price movements, with abundant solar generation pushing prices towards zero during midday before a sharp evening recovery.
OPCOM prices fell below €20/MWh before noon, reached zero across multiple fifteen-minute intervals and remained close to zero for several hours. After 17:00, prices began rising rapidly, exceeding €150/MWh during the evening and reaching €310/MWh shortly before 21:00.
Romania can therefore face renewable oversupply and power adequacy challenges on the same delivery day. The country has rapidly expanded solar capacity through both utility-scale projects and a growing prosumer fleet. However, this generation is highly concentrated in daylight hours and has limited flexibility to respond to market conditions.
At the same time, one of Cernavodă’s two 680 MW nuclear reactors is unavailable, while the remaining unit continues to face cooling-water risks. Hydropower output has also been weakened by record-low Danube flows and poor reservoir conditions. As solar generation declines in the evening, Romania may therefore need to rely on gas, coal, imports, storage or demand-side flexibility to cover the resulting shortfall.
Domestic demand was recently expected to reach around 7,300 MW, compared with available internal generation of approximately 4,000–4,300 MW during the tightest periods. While this does not represent a permanent hourly deficit, it illustrates how quickly Romania’s market can shift from zero prices to €300/MWh within a single day.
The situation creates an unusually clear opportunity for battery energy storage. A two-hour battery charging during the zero-price period and discharging around the evening peak could theoretically capture a spread approaching €300/MWh. Actual revenues would be lower after accounting for round-trip efficiency losses, degradation, grid charges, imbalance exposure and market-access costs, but the underlying arbitrage opportunity remains significant.
However, such spreads are unlikely to remain unchanged as Romania adds more storage capacity. Authorities are preparing commercial approvals for 324 MW of new capacity, including 176 MW of storage and 148 MW of photovoltaic and wind projects. A further 990 MW is reportedly moving through documentation and validation.
In the near term, additional storage will provide much-needed flexibility to the Romanian power system. Over the longer term, however, batteries will increasingly compete for the same low-price charging periods and evening discharge opportunities. Projects relying exclusively on day-ahead arbitrage may therefore face revenue compression, making balancing services, ancillary markets and congestion-related revenues increasingly important for long-term investment returns.
