Geological formations for hydrogen and CO2 storage discovered in Greece

Photo: Six possible CCS areas in Greece

Greek scientists have identified natural "reservoirs" for hydrogen storage in Corfu, Kefalonia and Aitoloakarnania, as well as other geological cavities throughout Greece, where quantities of carbon dioxide or even natural gas can be stored.

The important findings can serve as infrastructure for the path towards "net zero" by 2050 that the EU has outlined for the complete decarbonization of the European economy, a plan that has accelerated the promotion of new technologies, such as hydrogen production, but also carbon capture and storage .

The new challenges

At the same time, they could fill the lack of suitable places to store natural gas, a need that arose during the two-year energy crisis and efforts to wean itself off Russian gas.

These new challenges are addressed by the study of a large team of experts from the Hellenic Geological and Mining Research Authority (EGMR), the Departments of Geology of the National and Kapodistrian University of Athens and the University of Patras, as well as the National Center for Research and Technological Development (CERTH).

Regarding hydrogen, the storage capacity in salt "caves" (salt basins) on the islands of Corfu and Kefalonia was determined to be around 53,200 MWh (megawatt hours). These quantities are sufficient to cover the electricity needs of 6,770 households in the Ionian Islands.

Salt cavities

Also, saline cavities that could function as hydrogen storage facilities were identified in the Tryfos and Achyra areas in Central Aitoloakarnania, which can potentially accommodate 26,600 MWh.

According to the scientists who participated in the research work (Apostolos Arvanitis, Petros Koutsovitis, Nikolaos Koukouzas, Pavlos Tyrologos, Dimitris Karapanos, Christos Karkalis and Panagiotis Pomonis), hydrogen can be stored in porous reservoir rocks, such as depleted natural gas or oil deposits, as well as in salt "cavitations".

However, for Greece, these salt formations, as stated in "Vima" by the Director of Research at CERTH, Dr. Nikolaos Koukouzas, "are considered the most suitable for hydrogen storage because they allow higher injection and pumping rates compared to other storage methods, thus offering high efficiency in providing energy to the grid."

Natural gas storage

The study also identified suitable sites for natural gas storage.

Of the 22 candidate sites examined in various areas of Northern and Central Greece and the Aegean islands, those of the Mesohelleniki Avlaka (an area that occupies part of Northwestern Greece), the Western Basin of Thessaloniki and Voutsaras, Ioannina, emerged as suitable, presenting the best performance with the highest thermal power values ​​reaching up to 4,175 MJ (Megajoules).

Also, geological sites, such as aquifers, in four other areas, such as Sapes, Serres, Komotini (Agioi Theodoroi) and Lake Mitrikou, meet the conditions for storing natural gas.

The estimates show that these sites could cover the heating energy needs of the Region of Eastern Macedonia and Thrace. Three abandoned mines in Attica (Mandra and Chaidari) and Evia (Aliveri) were also examined. The results showed that they present lower average total thermal energy values.

In addition to geological aquifers, suitable underground geological spaces for gas and/or hydrogen storage were identified in Epanomi, Kavala and Heraklion, Crete.

CO2 storage

Regarding carbon dioxide (CO2) storage – in addition to the large investment being made by EnEarth (of the Energean group) in the depleted Prinos deposits , which are the only ones in Greece that have been identified as suitable and among the few sites that have been studied in the Mediterranean – researchers have indications of the suitability of three other areas.

In particular, studies of rocks, such as sandstones from the wider Grevena-Kastoria area (Mesohelleniki Avlaka) and basalts from Volos, have shown that geological formations could serve as potential CO2 storage sites in these two areas. Saline aquifers in the Western Basin of Thessaloniki have also been identified as suitable.

Printed edition Economic Courier (OT) – Sunday's Vima - in.gr