The European Union Agency for the Cooperation of Energy Regulators (ACER) has urged Greece to investigate whether electricity producers intentionally withheld generation capacity during the summer of 2024 to influence market prices. The agency also called for greater data transparency to improve monitoring and prevent potential market abuse.
According to ACER’s analysis, generation behavior played a decisive role in shaping electricity prices on the Greek day-ahead market between mid-June and mid-September 2024, when high demand and supply shortages led to sharp price increases. The report found that producers’ bidding patterns shifted during these tight market conditions, intensifying price spikes.
Examining data from the Hellenic Energy Exchange, ACER reconstructed supply and demand curves for 93 high-price hours—those exceeding 100 €/MWh. Among them, 17 hours were classified as “pressured,” reaching 500 €/MWh, and two hours as “critical,” with prices peaking at 900 €/MWh. The highest price, 942 €/MWh, occurred on 4 September 2024 at 8:00 PM.
ACER estimated that an additional 650 MWh of available generation during that period could have lowered the clearing price by roughly 630 €/MWh. In other scenarios, price reductions of 420 €/MWh under tight conditions and 100 €/MWh in normal circumstances were modeled.
The regulator concluded that under limited capacity or constrained cross-border flows, market prices become highly sensitive to generation levels, creating opportunities for market power manipulation. ACER emphasized that enhanced oversight and transparency are essential to preserve competition and market stability in Greece’s electricity sector.
