Despite the increase in electricity generation from Renewable Energy Sources (RES), Greece consistently remains among the most expensive countries in Europe in the day-ahead electricity market (DAM). According to a new analysis by The Green Tank, which also compares Greece with Portugal, the main reasons are the country’s growing dependence on fossil gas and the lack of energy storage infrastructure.
Greece’s wholesale electricity market is steadily among the most expensive in Europe, a fact that directly affects the retail prices paid by consumers. Although this issue is critical both for budgets and the competitiveness of the Greek economy, public debate often takes place without sufficient evidence.
The new Green Tank analysis, titled “What is causing high electricity prices?”, draws on real-time data collected daily by the European Network of Transmission System Operators for Electricity (ENTSO-E), and highlights the main factors influencing prices in the wholesale electricity market. Greece’s case is compared with Portugal—a country with similar characteristics but consistently lower prices in the Day Ahead Market (DAM).
Key findings of the analysis:
- In both countries, fossil gas shows the strongest positive correlation with prices—meaning it is linked to higher price levels. By contrast, RES—and pumped hydro storage in Portugal—show the strongest negative correlations, meaning they are associated with lower DAM prices.
- The gap between Greece’s average minimum price (12:00–13:00) and average maximum price (20:00–21:00) over the course of a day, widened from €128/MWh in 2024 to €143.4/MWh in 2025.
- This widening “spread” is partly due to a modest 5% increase in cheap RES generation during the first 10 months of 2025, and partly to a much larger increase in expensive fossil gas (+12.6%), which also fueled electricity exports.
Greece compared to Portugal:
- Has a more expensive and more volatile DAM. Since April 2022, Greece has been on average 36% more expensive than Portugal in the day-ahead market, with price fluctuations roughly twice as high.
- Uses more fossil gas. Over the past two years, Portugal has kept its average monthly gas share consistently below 25%—and on average 14%—while Greece remains above 32%, averaging 43.9%.
- Has less storage. Portugal has recently made major investments in pumped hydro storage, increasing its storage capacity to 3.71 GW, whereas Greece remains stagnant at a capacity nearly five times lower (0.7 GW). These facilities allow Portugal to store surplus cheap RES energy at midday and release it in the evening, reducing the need for expensive gas-fired generation.
“It is essential to reassess today’s energy choices, which deepen the power sector’s dependence on fossil gas, weakening the positive impact that renewables have on prices. The combination of RES and storage can—and must—become the key driver of a substantial and long-term reduction in electricity prices to the benefit of society and the economy,” said Nikos Mantzaris, policy analyst at The Green Tank.
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