Greece has an established upstream oil industry with numerous active onshore and offshore concessions. According to information published on the official site of HEREMA, based on preliminary estimates, Greece’s subsurface, with a focus on natural gas, could hold hydrocarbon reserves worth upwards of €250 billion. Considering the critical importance of Greece’s upstream sector, in April 2022, exploration and exploitation natural gas projects were elevated by the Greek State to projects of national importance, drastically accelerating licensing procedures in addition to timings for relevant government approvals.

As of the latest available data available on the official site of the Hellenic Hydrocarbons and Energy Resources Management Company (“HEREMA”), the active concessions are as follows:

• Prinos offshore block (Northern Greece) is in the production phase across three fields: Prinos, Prinos North, and Epsilon. While no recent production capacity data are available, as of December 2016, the Prinos reserve produced approximately 5,000 barrels per day.
• Exploration phase concessions include three offshore blocks in the Ionian Sea (Block 2, Block 10, and Ionian Block), two offshore blocks located west and southwest of Crete, and one onshore block at Ioannina.

In November 2025, ExxonMobil, Energean, and HELLENiQ ENERGY Upstream announced the execution of a farm-in agreement for ExxonMobil’s participation in the Block 2 concession. Under the agreement, ExxonMobil acquires a 60% interest, while the stake of Energean is reduced to 30% (from 75%) and the stake of HELLENiQ ENERGY to 10% (from 25%). Energean will remain the operator during the exploration phase, with ExxonMobil assuming operatorship in the development phase upon a hydrocarbon discovery. Completion of the transaction is subject to customary closing conditions and regulatory approvals. Exploratory drilling is anticipated in late 2026 or early 2027, subject to timely permitting and an extension of the exploration phase.

• Katakolo offshore block (Western Greece) is in the development phase.

It is noteworthy, however, that, as reported in January 2025, the Katakolo and Ioannina concessions are scheduled for abandonment and are in the process of being returned to the Greek State.

Following the expression of interest from international oil companies for the exploration and exploitation of hydrocarbons, HEREMA launched an international call for tenders with no. 27628/23.04.2025 for granting and using authorization for hydrocarbons exploration and exploitation within offshore Southern Peloponnese (Block Areas: “A2” and “South of Peloponnese”) and offshore Southern Crete (Block Areas: “South of Crete 1” and “South of Crete 2”), which was approved by the Ministry of Energy and Environment (YPEN) by virtue of the ministerial decision 46430/1073 (ΦΕΚ Β’ 2104/30.04.2025) (Government Gazette B΄2104/30.04.2025). Announcement of the Greek State in relation to the international call was published in the ISSUE 3335/12.6.2025 OF THE EUROPEAN JOURNAL on 12.06.2025. The template lease agreement was published on the official site of HEREMA on 16.06.2025. The Chevron (operator) and HELLENiQ ENERGY consortium was selected as preferred bidder. As reported in January 2026, the four concession agreements granting to Chevron–HELLENiQ Energy consortium the rights of exploration and exploitation over the four offshore blocks in Crete and the Peloponnese are scheduled to be ratified by the Greek Parliament toward the end of January 2026. The Greek government’s goal is the geophysical and seismic surveys to commence within 2026.

Upstream oil and gas activities in Greece are primarily governed by Law 2289/1995 (Greek Government Gazette Α’ 27/08.02.1995) (the “Hydrocarbons Law”), which transposed Directive 94/22/EC into Greek law. The Hydrocarbons Law was substantially amended by Law 4001/2011 (Greek Government Gazette Α’ 179/22.8.2011) with the aim of modernizing the hydrocarbons exploration framework and enhancing its attractiveness to prospective investors.

The right to prospect for, explore, and exploit hydrocarbons located in onshore, sub-lake, and offshore areas over which the Greek State exercises sovereignty or sovereign rights, in accordance with the United Nations Convention on the Law of the Sea, as ratified by Law 2321/1995 (Greek Government Gazette Α’ 136/23.06.1995), are vested exclusively in the Greek State and must at all times be exercised in the public interest. The management, on behalf of the State, of such rights is carried out by the state-owned HEREMA.

Exploration and exploitation rights are granted by HEREMA by means of execution of either a lease agreement or a production sharing agreement, following either a call for tender in respect of a specifically defined area and the submission of offers, or an expression of interest by a third party in respect of a specific area, or an “open door” procedure for the submission of offers for permanently available areas or areas previously under concession or abandoned by the concessionaire. Although production sharing agreements are provided for under the Hydrocarbons Law, active concessions in Greece are currently in the form of lease agreements. Once concluded, lease agreements are ratified by the Greek Parliament and published in the Greek Government Gazette, thereby acquiring the force of law and providing investors with enhanced protection against subsequent legislative changes that may affect the project.

Eligible concessionaires may be either natural persons or legal entities that are nationals of, or have their registered seat in, an EU Member State, or in third countries with which reciprocity agreements are in place. For reasons of national security, the Council of Ministers may prohibit participation in the concession process by entities substantially controlled by third countries or by nationals of third countries, as well as by joint ventures involving such entities.

Concession areas are limited to the area in which commercially viable resources are discovered and may not exceed 100 square kilometres (or, under specific conditions, 200 square kilometres).

Confiscation of exploration and exploitation rights is not permitted; however, extracted hydrocarbons that do not belong to the Greek State may be subject to confiscation.

Presidential Decree 127/1996 (Government Gazette A’ 92/1996) further specifies the terms governing the leasing of hydrocarbon exploration and exploitation rights. Under this Decree, operators are required to submit to HEREMA, on an annual basis, an operations plan and budget and, following the commencement of exploitation, a development and production plan. The Presidential Decree 127/1996 also sets out provisions concerning the payment of rent, the valuation of hydrocarbons, the procedures following the discovery of commercially viable deposits, the conditions for extending the period within which the concessionaire must fulfil its obligations, the concessionaire’s obligation to remove all installations upon expiration of the exploitation phase, and the subsequent restoration of the environment.

In the case of lease agreements, the fee payable by the investor typically consists in royalties/lease fees (although payment in kind could also be agreed) whereas the production sharing contracts provide for the allocation of part of the extracted hydrocarbons to the Greek State. In both cases, the agreements may also provide for a signing bonus payable upon execution of the lease contract or the production sharing contract, or a production bonus, or an annual surface fee payable during the exploration and exploitation phase calculated on the basis of the surface of the area used by the contractor.

In addition, under both types of agreements, the Greek State may participate directly in the project through a joint venture with the relevant concessionaire; however, this option has not been exercised in any concession agreements concluded to date.

From a structural perspective, both types of agreements provide for an exploration phase with a maximum duration of seven (7) years for onshore operations and eight (8) years for offshore operations subject to renewal for specific reasons set forth in the law. They also provide for an exploitation phase which with a maximum duration of twenty-five (25) years from the date on which concessionaire notifies he discovery of hydrocarbons in the relevant area. Upon commencement of the exploitation phase, the concession area is reduced to the area in which commercially recoverable hydrocarbon reserves have been identified.

Changes in the Concessionaire’s structure are in general permissible subject to specific terms and conditions and the prior approval of the Greek State. Restrictions, including limitations on transfer of rights and obligations to third parties, may be imposed on grounds of national or public interest. At any stage, additional terms and conditions may also be imposed on the exercise of concession rights and on the hydrocarbons produced for reasons of national security.

Finally, although commonly used in international practice, service agreements are not provided for under Greek legislation.

Unconventional hydrocarbon resources, including shale oil and gas, extra-heavy oil, natural bitumen (oil sands), or tight oil and gas, are not currently exploited within Greek territory. Shale oil and gas are expressly excluded from the scope of application of the Hydrocarbons Law.

The key regulatory authorities for the upstream oil and gas sector in Greece are the Ministry of Environment and Energy and the Hellenic Hydrocarbons and Energy Resources Management Company (“HEREMA”).

HEREMA was established pursuant to Article 145 of Law 4001/2011 and the Presidential Decree No. 14/2012 (Government Gazette Α΄ 21/13.02.2012) and has undergone significant restructuring since the summer of 2020 under Article 131 of Law 4685/2020 (Government Gazette A’ 92/07.05.2020). Among other responsibilities, HEREMA possesses specific regulatory and supervisory powers in the upstream oil and gas market. Additionally, since July 28, 2016, HEREMA has been appointed as the transitional competent authority for offshore safety in oil and gas operations in Greece under Law 4409/2016 (Government Gazette A’ 136/28.07.2016), which transposed Directive 2013/30/EC in Greek Law, and within this framework currently exercises certain regulatory functions as stipulated in Article 8 of the same law.

The Ministry of Environment and Energy also plays a key role in the upstream oil and gas sector. In particular, in addition to defining areas designated for exploration and exploitation activities, the Ministry of Environment and Energy, is also actively involved in granting concession rights and monitoring the performance of investors under the concession agreements.

The Greek State does not participate directly in the upstream oil and gas sector. While exploration activities were historically undertaken by the State, and the Hydrocarbons Law provides for the possibility of the State participating directly in concession agreements through a joint venture with the concessionaire, this option has not been exercised in any of the concession agreements concluded to date.

The main Greek players in the upstream oil market are the private companies HELLENiQ ENERGY (formerly the Hellenic Petroleum Group) and Energean. It is noteworthy, however, that 31.18% of HELLENiQ ENERGY’s shareholding is currently held by the Growth fund, which is fully owned by the Greek State.

In principle, any foreign oil and gas company may participate in the upstream sector in Greece. However, the Hydrocarbons Law provides that, upon HEREMA’s recommendation, the Council of Ministers may prohibit participation by entities substantially controlled by third countries or by nationals of third countries, as well as by joint ventures involving such entities, on grounds of national security.

Similarly, any change of control of a concessionaire during the term of a concession agreement that would result in direct or indirect control by a non-EU state or non-EU national may only occur with the prior approval of the Council of Ministers. Failure to obtain such approval will result in the revocation of the concessionaire’s rights.

In addition, foreign investments in oil and gas may be captured by Law 5202/2025 on measures implementing Regulation (EU) 2019/452 establishing a framework for the screening of foreign direct investments into the Union on grounds of security or public order (“FDI Law”), which provides that certain acquisitions or investments by non-EU investors in Greek entities may be subject to notification to, and screening by, the Interministerial Committee for the Screening of Foreign Direct Investments. The FDI Law captures several sectors of the economy, including “energy”, while according to the official guidance provided to date by the Ministry of Foreign Affairs (which is the competent supervisory authority) what fall within the scope of each sector should be interpreted broadly. The Joint Ministerial Decision regarding the FDI filing procedure was published on the Government Gazette on 11.11.2025, (Decision No. 64260, G.G. 6009/B/11.11.2025), essentially kicking off the notification process for the FDI regime in Greece.

Pursuant to Joint Ministerial Decision 107017/28.8.2006 (Government Gazette B’ 1225/5.9.2006), which transposed Directive 2001/42/EC into Greek law, as amended and currently in force, a Strategic Environmental Impact Assessment (SEIA) must be prepared and approved by the Environmental Licensing Directorate of the Ministry of Environment and Energy prior to the granting of prospection, exploration, or exploitation rights for any specific onshore or offshore blocks. The preparation and approval of the SEIA constitute a fundamental precondition for the development of upstream oil and gas activities, as such operations are legally recognized as having a significant environmental impact.

In addition, pursuant to Greek law the operations and activities related to the exploration and exploitation of oil and gas are subject to the issuance of an approval of Environmental Terms (AET) by the Environmental Licensing Directorate of the Ministry of Environment and Energy, on the basis of an Environmental Impact Assessment (EIA), which must be submitted to the Ministry together with the application for the AET. The EIA is also subject to public consultation with relevant stakeholders and administrative authorities.

Furthermore, Article 12A of Greek Law 2289/1995 provides that the prospection, exploration, and exploitation of hydrocarbons must be conducted in accordance with the European Union guidelines issued in response to the Deepwater Horizon drilling rig incident in the Gulf of Mexico, establishing a strict framework for environmental, health, and safety standards in upstream operations in Greece. Under this framework, concessionaires are required to carry out hydrocarbon activities in a proper and safe manner, in compliance with best international practices, applicable regulations, and all relevant legislation governing worker safety, hygiene, and environmental protection. Specifically, among other obligations, concessionaires must ensure that: (a) all materials, machinery, equipment, and installations used are constructed and operated in accordance with generally accepted petroleum industry standards; (b) natural resources within the licensed area are used in a sustainable manner; (c) applicable waste management and wastewater regulations are observed; and (d) damage to productive formations and adjacent hydrocarbon layers is prevented. In the event of non-compliance with the applicable environmental, health, or safety requirements, concessionaires are obliged to implement all corrective measures within a deadline determined by HEREMA.

Finally, a dedicated framework for safety in offshore hydrocarbon exploration and exploitation operations was established under Law 4409/2016. This law sets out the minimum requirements for the prevention of major accidents in offshore hydrocarbon operations, as well as measures to mitigate their potential consequences. Prospection licenses and concession agreements for offshore exploration and exploitation are granted only after HEREMA has assessed the applicant’s ability to comply with the requirements for conducting the relevant activities, particularly in accordance with the provisions of the aforementioned law.

As mentioned in our reply to question 3 above, the fee payable by the investor typically consists in royalties/lease fees (although payment in kind could also be agreed) whereas the production sharing contracts provide for the allocation of part of the extracted hydrocarbons to the Greek State. In both cases, the agreements may also provide for a signing bonus payable upon execution of the lease contract or the production sharing contract, or a production bonus, or an annual surface fee payable during the exploration and exploitation phase calculated on the basis of the surface of the area used by the contractor.

Furthermore, under Article 8 of the Hydrocarbons Law, concessionaires benefit from specific tax incentives applicable to each concession contract, including a special 20% income tax and a 5% regional tax, and are therefore exempt from any additional taxes or levies.

There are no general restrictions on the export of hydrocarbons.

The Hydrocarbons Law contains provisions designed to facilitate the import of equipment from abroad and the employment of non-EU personnel for work requiring specialized skills and expertise.

Regarding local content obligations, concessionaires are required to provide annual training to local technical and scientific personnel in accordance with specific terms and conditions established by law.

The Hydrocarbons Law establishes decommissioning obligations at the end of the exploitation phase. More specifically, the concessionaire is required to properly seal all producing wells and aquifers, remove all installations, and restore the area a sound environmental condition. Corresponding requirements are also incorporated into the concession agreements.

The concessionaire may sell any equipment or materials resulting from the dismantling of unused installations, provided that HEREMA is notified in advance of the items to be sold and their respective prices.

The construction of onshore and offshore oil and gas pipelines is subject to prior environmental licensing and the issuance of an installation and operation license by the administrative authorities. The issuance of other secondary licenses and permits (e.g. building permits) may also be required.

As regards specifically the environmental licensing, the construction and operation of onshore and offshore oil and gas pipelines is considered as an activity with significant impact on the environment and for this reason is subject to the issuance of an approval of Environmental Terms (AET) by the Environmental Licensing Directorate of the Ministry of Environment and Energy, on the basis of an Environmental Impact Assessment (EIA), which must be submitted to the Ministry together with the application for the AET. The EIA is also subject to public consultation with relevant stakeholders and administrative authorities.

Please refer to the answer to the Question 15 below for information on the regulatory regime applying to the construction and operation of the National Natural Gas System (“NNGS”).

The construction and operation of Independent Natural Gas Systems (INGS), which do not form part of the National Natural Gas System (irrespective of whether they are interconnected with it), are subject to prior licensing by RAAEY. The construction licence is granted exclusively to legal entities by decision of RAAEY, following an assessment of the criteria set out in Law 4001/2011, including, inter alia, the applicant’s financial and technical capacity and the extent to which the project enhances competition in the natural gas sector. In addition, the licence holder is required to obtain a separate operator licence for the management and operation of the INGS, which is distinct from the construction licence and is also issued by RAAEY. Where an INGS is located in more than one country, RAAEY cooperates with the competent regulatory authorities of the other countries concerned.

Oil pipelines are also subject to prior licensing in accordance with the terms and conditions set out in Law 3054/2002 (Government Gazette A’ 230/2.10.2002) on the organization of the downstream oil market.

To date, the LNG terminal on Revithoussa Island, which owned and operated by DESFA (the operator of the National Natural Gas Transmission System), and the Floating Storage and Regasification Unit (FSRU) at Alexandroupolis, which is owned and operated by GASTRADE S.A., are the LNG terminals currently in operation in Greece.

The Revithoussa terminal has a storage capacity of 225,000 m3 and a regasification capacity of 1400 m3/h and the Alexandroupolis LNG terminal, which commenced its operation in October 2024, has a storage capacity of 153,500 m3 and a regasification capacity of 944,000 Nm³/h.

The LNG terminal at Revithoussa, qyalifying as essential facility, is subject to extensive regulation. In particular, pursuant to Article 15 of EU Regulation 715/2009, the operation of the terminal is subject to third-party access rules, requiring the transmission system operator to grant access to all users on a transparent and non-discriminatory basis. The detailed terms and conditions governing third-party access to the terminal are set out in the Network Code of the National Natural Gas Transmission System. Under Articles 70A and 71 of the Network Code, any company seeking to use the Revithoussa facilities and concurrently acting as a user of the National Natural Gas Transmission System must apply to DESFA for the provision of the Basic LNG Service and subsequently enter into the standard LNG Facility Use Agreement.

Conditions ensuring compliance with EU Regulation 715/2009 also apply to the Alexandroupolis LNG terminal, to the extent that such conditions do not conflict with RAAEY Decision No. 1333/2022, which granted the Alexandroupolis LNG terminal an exemption from the application of Articles 9, 32, and 41(6), (8), and (10) of Directive 2009/73/EC. Pursuant to that decision, the applicable conditions relate, inter alia, to: (i) transparency and disclosure of information; (ii) the implementation of anti-hoarding measures; and (iii) the offering of short-term capacity products. Furthermore, the decision clarifies that neither EU nor national legislation restricts GASTRADE S.A. from offering the non-exempted portion of the terminal’s capacity under long-term contracts of any duration, provided that such capacity is offered in a transparent and non-discriminatory manner and in accordance with EU Regulation 715/2009.

Investment interest in floating LNG terminals in Greece is gaining momentum following agreements positioning the country as a gateway for U.S. LNG into Europe, bringing several major FSRU projects back into focus after a period of relative inactivity. The FSRU project “Dioriga Gas,” developed by Dioriga Gas S.A. (of Motor Oil interests) at Motor Oil’s Corinth refinery, has been granted a five-year installation licence covering both the floating storage and regasification unit and the permanent mooring port infrastructure, with commercial operations expected to commence by the end of 2026.

In addition, three other FSRU projects are progressing through their development phases: the Thrace FSRU offshore Alexandroupolis (Gastrade), the FSRU Thessaloniki (HELLENiQ ENERGY), and the FSRU ARGO (Mediterranean Gas consortium), planned at the port of Volos.

To date, there are no operating gas storage facilities in Greece.

A licence for the exploitation of an underground natural gas storage facility (UGS) in the South Kavala natural gas reservoir was granted in 2011 to Energean Oil and Gas S.A. which was subsequently extended multiple times thereafter. In 2022, the Hellenic Republic Asset Development Fund (HRADF) launched a tender for the use, development, and operation of the South Kavala UGS; however, the tender concluded in March 2023 without any awardees, reflecting limited market interest. Following the unsuccessful tender process, the Ministry of Environment and Energy (YPEN) further extended the exploitation licence through successive decisions, currently valid until 23rd November 2026.

The construction and operation of onshore hydrocarbon storage tanks require an installation and operation permit issued by the Minister of Environment and Energy, pursuant to Article 6, paragraph 1 of the Hydrocarbons Law. Offshore construction is also permitted but is subject to the prior approval of both the Minister of National Defence and the Minister of Shipping and Island Policy.

The National Natural Gas System (“NNGS”) comprises of the main gas transmission pipeline and its branches, the border metering stations at Sidirokastro and Kipi, the compression station at Nea Mesimvria, Thessaloniki, the Natural Gas Metering and Regulating Stations, the Natural gas Control and Dispatching Centers, and remote control and communication systems. Users can theoretically purchase natural gas at an entry point and sell it at an exit point. Sale at a virtual point is also allowed, hence allowing for reverse flows. The NNGS is currently interconnected with Turkey, Bulgaria and the LNG Terminal at Revythoussa and the FSRU in Alexandroupoli.

The activity of third parties is mainly focused on bringing LNG into the LNG Terminal at Revythoussa and the FSRU in Alexandroupoli purchased on the spot market. DEPA Commercial has signed long-term pipeline gas supply contracts with the Russian company Gazprom Export and the Azeri AGSC (Azerbaijan Gas Supply Company) and a long-term partnership with the Algerian company Sonatrach, from which it has been supplying quantities of LNG for 25 years.

The NNGS is currently owned and operated by DESFA S.A., where the State participates with a 34% stake.

The construction, operation and management of natural gas distribution systems is subject to the issuance of a distribution license and an operation license by RAAEY. Pursuant to the provisions of Law 4001/2011, and following a recently occurred merger, there are several natural gas distribution networks per geographical areas each operated by a separate grid operator licensed as above.

The supply to end – customers is liberalized in Greece and anyone wishing to proceed to the relevant activities may obtain a relevant supply licence. Similarly, the activities of import/export and purchase or sale of natural gas in any other way may be freely exercised (i.e. without a licence) provided that the relevant entity becomes registered as a User of the NNGS in the Users Registry held by RAAEY and enter into a Use of NNGS agreement with DESFA. There are currently more than 40 license holders in the market. Customers are free to choose their supplier.

The supply of natural gas to end customers is subject to the issuance of a natural gas supply licence. Such licences are issued, amended, and revoked by RAAEY in accordance with the terms and conditions set out in the Natural Gas Licensing Regulation (Ministerial Decision No. 178065/2018, Government Gazette B’ 3430/17.08.2018). The issuance of a supply licence is subject to specific conditions, including: (a) the origin of the applicant company, which must generally be a legal entity with its registered seat in the EU or the European Economic Area; and (b) a minimum share capital, which must be at least €600,000. Other criteria concern the applicant’s organizational and administrative structure, which must be sufficient to ensure the reliable and uninterrupted provision of services, as well as its financial standing and creditworthiness.

Natural gas supply licences are granted for a period of up to twenty (20) years and may be renewed upon written request to RAAEY at least one year prior to the licence’s expiration. Natural gas supply licences may be revoked, among other reasons, for breach of obligations provided by law or in the event of the licensee’s insolvency.

The activity of natural gas distribution is likewise subject to the licensing requirements described above and is supervised by RAAEY. Additionally, the sector is governed by a set of rules derived from both EU and domestic legislation, including the Regulation on Wholesale Energy Market Integrity and Transparency (EU Regulation 1227/2011 – REMIT) and EU Regulation 715/2009 on conditions for access to natural gas transmission networks.

Reference is also made to Laws 4425/2016 (Government Gazette Α 185/30.9.2016) and 4512/2018 (Government Gazette Α’ 5/17.01.2018), which established the new energy exchange market. In particular, the energy exchange natural gas trading platform became operational in March 2022, replacing the previous market structure of the balancing platform operated by DESFA. The platform is operated by Energy Exchange S.A. (pursuant to Article 19 of Law 4425/2016 and RAAEY Decision 60/2022) and enables anonymous trading for the short-term supply of natural gas, thereby enhancing market liquidity. It should also be noted that, under Article 10 of EU Regulation 312/2014, DESFA S.A. remains responsible for balancing the gas transmission system and participates in the domestic energy exchange market solely to cover the system’s balancing requirements.

As noted above, the most significant recent changes in government policy and regulation are: the approval of new upstream concessions in offshore Southern Peloponnese (“A2” and “South of Peloponnese”) and Southern Crete (“South of Crete 1” and “South of Crete 2”) (see Question 1), which are significant as they mark a major expansion of exploration and development activity in Greece’s hydrocarbon sector; the strengthened focus on Greek FSRU projects (see Question 13), which is important for enhancing the country’s LNG import capacity and energy security; and the introduction of the FDI Regime, whichis significant because it may directly affect foreign investment decisions and the overall attractiveness of Greece as an investment destination (see Question 9).

The oil and gas landscape in Greece has been fundamentally reshaped by the EU’s decisive move to end dependency on Russian pipeline gas and the positioning of Greece as a strategic gateway for U.S. LNG into Southeast Europe. In 2025, Greece signed a 20-year LNG supply agreement with U.S. producers, commencing in 2030, which diversifies its gas imports away from traditional pipeline sources. This landmark deal has accelerated Greece’s emergence as a regional LNG hub, leveraging existing infrastructure such as the Revithoussa terminal and the planned FSRU Alexandroupolis, while additional investments in FSRU projects are prioritized to mitigate geopolitical risks related to regional energy security and supply stability.

The National Climate Law 4936/2022 (Government Gazette Α 105/27.05.2022) establishes Greece’s framework for achieving climate neutrality, with direct implications for the oil and gas sector. Key measures include: (i) prioritizing the reduction of electricity generation from liquid fossil fuels through the interconnection of non-interconnected islands to the mainland grid, the expansion of renewable energy sources (RES), and the promotion of energy storage; and (ii) the gradual substitution of natural gas with renewable gases, such as biomethane and green hydrogen, particularly in transport and industrial applications. In terms of regulatory obligations, Article 20 of the National Climate Law required natural gas suppliers to publish a carbon footprint report by 31 October 2023, which may voluntarily include measures aimed at emissions reduction. Additionally, the Ministry of Environment and Energy retains the authority to impose binding emissions-reduction targets on natural gas suppliers starting 1 January 2025, based on sector-specific five-year carbon budgets. These provisions reflect a structured approach to integrating climate objectives into the operational and strategic planning of the oil and gas industry in Greece.

Law 5215/2025 (Government Gazette A’ 116/04.07.2025) establishes Greece’s first comprehensive regulatory framework for hydrogen, representing a major milestone in developing a competitive hydrogen economy capable of meeting industrial demand while supporting national decarbonisation and climate objectives. The Law regulates renewable and low-carbon hydrogen, distinguishing off-grid from grid-connected production units, and introduces a two-phase licensing process: a Producer Certificate (valid up to 25 years) and environmental/operational permits, including grid connection for on-grid units. Hydrogen qualifies as renewable under EU criteria or through additionality, temporal, and geographic correlation, allowing for the issuance of Guarantees of Origin. The Law also establishes Geographically Confined Hydrogen Networks (GCHNs) standalone networks serving local industrial or commercial needs—which require RAAEY-issued construction and management licences, may be subject to public tenders, and will undergo a seven-year market review. Detailed operational rules will be set out in a forthcoming GCHN Network Code. To promote early market development, the Law allows investment and operational support schemes, fostering sustainable growth across the hydrogen value chain. Although it only partially transposes Directive (EU) 2024/1788 on renewable gas, natural gas, and hydrogen markets, the legislation aligns Greece with EU hydrogen market design, supports the implementation of decarbonisation targets, and advances the goals of the National Energy and Climate Plan (ESEK).

In addition, as regards hydrogen production strategies, it is noteworthy that the Greek State has integrated hydrogen initiatives into a dedicated investment framework under Law 4864/2021 (Government GazetteΑ’ 237/02.12.2021), which establishes a regime for “strategic investments” aimed at enhancing the investment climate by streamlining and accelerating approval processes. Under this framework, green hydrogen projects may qualify for enhanced incentives if designated as “emblematic investments of exceptional importance,” including subsidies, tax exemptions, and expedited licensing procedures, thereby supporting the rapid development and commercialization of the hydrogen sector in Greece.

Law 5261/2025 (Government Gazette A’ 231/12.12.2025) establishes a comprehensive and unified legal framework for the capture, utilisation, transport and geological storage of carbon dioxide (CCS) in Greece, in accordance with Directive 2009/31/EC. CCUS activities are classified as services of general interest and are subject to prior permitting, while CO₂ transport is regulated under third-party access rules. Exploration and geological storage of CO₂ remain reserved to the Greek State and may be granted to private operators exclusively through competitive award procedures. The law also provides for insurance obligations and measures in the event of leaks or significant irregularities. Furthermore, Law 5261/2025 introduces a structured regime for access to CO₂ storage sites and capacity allocation, based on a dual model. A predefined share of storage capacity is allocated through regulated access, on an equal basis and at a reference tariff reflecting the weighted average cost of capital (WACC) and infrastructure costs, subject to minimum annual emissions-reduction contributions under the EU Emissions Trading System. Regulated access is secured through long-term contracts of at least 15 years, incorporating “store-or-pay” obligations and financial guarantees. The remaining capacity is allocated through public international tenders, under contracts of shorter duration (minimum five years), with rights and obligations being transferable. The framework also allows for additional tenders to be launched for unused or newly available capacity, including short-term arrangements of up to five years. It is noteworthy that the implementation of the CCUS regime currently largely depends on the timely adoption of a great number of delegated acts and regulatory instruments.

EnEarth (of Energean’s interest) currently owns and develops the Prinos CO₂ Storage project, the only CO₂ storage facility in Greece, designed to support local and regional decarbonisation by storing captured CO₂ from hard-to-abate sectors, including direct air capture and BECCS technologies, the shipping industry, and other industrial sources. Following the award of an exploration permit in September 2022, EnEarth submitted a CO₂ Storage License application to HEREMA on 30 June 2024. The project will be developed in phased stages to align with growing demand. The first phase will repurpose existing infrastructure to achieve an injection capacity of 1 MtCO₂/year in 2026–2027. The second phase is planned to expand capacity to approximately 2.8 MtCO₂/year of liquid CO₂ by 2029–2030 for around 20 years.