Greece’s PV fleet keeps power system running during heatwave

Greece's Independent Power Transmission Operator (IPTO) says that the country hit a record this week, with afternoon electricity demand reaching 10,345 MW – the highest point this year.

Renewable energy, including large hydro plants, covered about half of this demand, at 5,015 MW. Specifically, solar contributed 3,485 MW of capacity, according to IPTO. The remaining capacity was sourced from power flowing through interconnectors from neighboring countries, as well as from Greece's fossil gas and lignite power plants.

The Greek power system faces a persistent challenge due to successive heatwaves and wildfires since the beginning of July. Despite this, IPTO stated that it responded to the challenge with absolute success, ensuring continuous operation of the system.

Traditionally, summer afternoons posed the hardest times for safeguarding the electricity system from blackouts in Greece. However, bulk solar installations have reversed the problem.

The Greek Ministry for the Environment and Energy has encouraged electricity consumers to primarily use grid electricity between 2 p.m. and 6 p.m. when solar power injection into the network is abundant. The ministry also advised Greeks to avoid energy-intensive activities like washing during the night, when solar parks do not generate power.

Although Greece set a demand record of 10,345 MW at 3 p.m. on Tuesday of this week, nighttime demand remained high at 9,388 MW at 8 p.m. and 9,144 MW at 9 p.m. During heatwaves, wind power output tends to be low, resulting in fossil fuel plants dominating the electricity mix.

In 2022, approximately half of Greece's electricity was generated from clean power plants, and the government aims to increase the penetration of green energy in the power mix. The recent heatwave experience highlighted the urgent need for energy storage.

Currently, the tendering of 1 GW of standalone, in-front-of-the-grid batteries is ongoing, with incentives for small residential storage units and licensed, co-located renewable power and storage plants that enjoy priority grid connection. Without significant energy storage capacity, Greece will be unable to phase out its dirty lignite fleet while continuing to rely on gas.

Interconnections play a crucial role in managing the heatwave challenge. IPTO attributed its successful operation during this period to the completion of two new interconnection lines: the Megalopolis-Patras-Acheloos line within Greece and a 400 kV electrical interconnection between Greece and Bulgaria, in addition to an existing line to Bulgaria installed years ago.

IPTO also emphasized two other factors contributing to its successful operation: regular checks on critical equipment to address any technical issues that may arise and the “trial operation of two new thermal units.” However, it remains unclear whether and how Greece can phase out its thermal units.