Temperatures are set to “hit red” through the weekend, with many regions in Greece expected to reach or exceed 44°C. The first major heatwave of the summer brings surging energy consumption and puts the state mechanism on high alert.

Initial estimates predict demand will reach 10,500–10,600 MW during midday hours in the coming days, and around 9,400 MW in the evenings—when solar production drops to zero and air conditioner use peaks. These levels are similar or slightly lower than last year. The peak days are expected to be Thursday and Friday, when nighttime demand will be met by conventional units (natural gas, lignite), wind power (depending on wind conditions), and electricity imports.

Wholesale price jumps 26% tomorrow

The steady rise in demand is pushing wholesale electricity prices higher. Starting tomorrow, prices are expected to increase by 26%, reaching €140.25/MWh, with the daily peak price projected to exceed €327/MWh.

One encouraging factor is the addition of two new natural gas power units to the grid this year: the Metlen unit in Viotia and the GEK TERNA–Motor Oil unit in Komotini. These two plants contribute over 1.6 GW of net available capacity, offering a valuable buffer during peak demand periods. Natural gas remains the backbone of power production, expected to cover 42% of tomorrow’s daily energy mix. Renewables (RES) exceed 32%, while imports are also high at 11.84%.

Hydroelectric reserves near historic lows

The sharp rise in temperature also shifts attention to hydroelectric reserves, traditionally a safeguard during peak demand. This year, however, the picture is concerning: reservoir levels have fallen below 2,000 GWh, currently at 1,920–1,930 GWh—the lowest in the past 20 years. Over the last two years, more than 800 GWh have been lost, including a 300 GWh drop since last year, leaving hydropower contributing just ±5% to the daily energy mix.

This energy pressure is not unique to Greece. Across Southeastern Europe, prolonged drought has caused water levels to plummet. In Hungary, the Danube’s water level in mid-July is already at levels usually seen in late August. Similar conditions prevail in Bulgaria, Romania, and the Western Balkans, creating a broader regional energy instability.

Fragile balance, focus on consumption

For now, the system is holding steady, but the prolonged heatwave, combined with potential equipment failures or emergency demands from countries like Ukraine, increases the risk of disruption.

As early as last Sunday, the issue was the focus of an emergency meeting at the Ministry of Environment and Energy, chaired by Minister Stavros Papastavrou, with participation from IPTO (ADMIE), DEDDIE (HEDNO), and the Regulatory Authority for Energy (RAE). The aim was to assess the system’s readiness to handle possible failures or malfunctions caused by high thermal loads.

Initial reports presented at the meeting indicated adequate capacity, both in available power generation and technical staff ready to respond where needed. However, market sources emphasize that this does not allow for complacency, as the duration and intensity of the heatwave may push the system’s resilience to the limit.