Greece is preparing to restart geothermal energy investments across seven regions following the completion of a Strategic Environmental Impact Assessment (SEA), a key step that could reshape the country’s renewable energy landscape.

The initiative, led by the Ministry of Environment and Energy, aims to unlock a sector that has remained largely underdeveloped despite significant underground potential. A previous tender launched in 2023 was suspended due to limited investor interest, driven by high costs, regulatory complexity, grid connection challenges, and perceived investment risk.

A new competitive process is now expected toward the end of 2026, pending improvements in investment conditions and access to the electricity network.

A roadmap for geothermal development

The newly completed assessment outlines the framework for future geothermal exploration and development. It is designed to guide upcoming tenders for exploration and exploitation rights, while reducing uncertainty that has so far discouraged investment.

Officials describe the plan as a “roadmap” for identifying and managing geothermal resources, balancing energy potential with environmental and socioeconomic considerations.

Seven regions with energy potential

The focus is placed on seven geographically diverse areas identified through geological and technical data as having promising geothermal potential. These include parts of northern and eastern Greece as well as several islands and coastal zones.

The regions under consideration are the Strymon Basin (central and southern sections), Akropotamos in Kavala, the western Nestos Delta basin, the Evros Delta, the Spercheios basin, the island of Samothraki, and southern Chios.

Three development scenarios

The study evaluates three possible development paths.

The first, a “no action” scenario, is effectively dismissed as it would leave domestic geothermal resources unused, limiting energy diversification and maintaining reliance on conventional energy sources.

A partial development scenario is considered more realistic but insufficient, as it would not generate a strong investment base or significant long-term benefits.

The preferred option is full-scale development across all seven regions. This approach is presented as the most comprehensive, enabling systematic resource exploration and stable energy production.

Unlike wind or solar energy, geothermal power can provide continuous electricity generation, making it suitable as a stable base source for the energy system.

Regional geothermal profiles

Each of the seven areas presents distinct geological characteristics and energy potential.

In the Strymon Basin, existing geothermal fields show temperatures reaching up to 75°C, with deeper systems expected to yield higher values.

In Kavala’s Akropotamos area, temperatures of up to 90°C have been recorded, with estimates suggesting even higher temperatures at greater depths.

The Nestos Delta basin also shows strong potential, with recorded temperatures up to 78°C and deeper reserves potentially exceeding 100°C.

In the Evros Delta region, geothermal fields such as Aristi indicate temperatures close to 100°C, while deeper systems could reach up to 150°C. Similar estimates apply to nearby thermal areas.

Samothraki presents a smaller but active hydrothermal system, while southern Chios shows promising shallow geothermal readings of up to 83°C, with deeper potential significantly higher.

The Spercheios basin, which includes well-known thermal sites such as Thermopylae and Kamena Vourla, is considered one of the most developed geothermal areas, with temperatures above 80°C already recorded in coastal zones.

Investment outlook

Despite past delays, the renewed framework signals a shift toward structured geothermal development in Greece. If implemented, the plan could open new opportunities for renewable energy production, reduce dependence on imports, and strengthen the country’s long-term energy security.

The success of the initiative, however, will depend on whether upcoming policy changes are able to address longstanding barriers to investment and ensure reliable access to infrastructure.