On the edge of an energy razor: Heatwave up to 44°C tests the power grid

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