SUBSURFACE ENERGY STORAGE: OPPORTUNITIES AND CHALLENGES FOR GEOLOGICAL STORAGE OF CO2 AND HYDROGEN

Ochuele Dominic Agida 1, Moses Adondua Abah1, Micheal Oladosu Abimbola1, Umunna Christopher Chukwuebuka2.

1.Geology Department, Federal University of Technology, Owerri, Imo State, Nigeria, 2. Research Hub Nexus Institute, Nigeria.

Corresponding Author: Geology Department, Federal University of Technology, Owerri, Imo State, Nigeria, Email: m.abah@fuwukari.edu.ng.

Citation: Ochuele Dominic Agida et, al. (2026). Subsurface Energy Storage: Opportunities and Challenges for Geological Storage of CO2 and Hydrogen. Eco Science Journal.2026 3 (12).

Copyrights © 2026, Ochuele Dominic Agida, Moses Adondua Abah, Micheal Oladosu Abimbola, Umunna Christopher Chukwuebuka. This article is licensed under the Creative Common Attribution-NonCommercial-4.0-international-License-(CCBY-NC).

ABSTRACT: The transition to low-carbon energy systems requires scalable technologies capable of reducing greenhouse gas emissions while enhancing energy security. Subsurface energy storage has emerged as a strategic solution, with geological carbon dioxide (CO₂) storage supporting carbon capture and storage (CCS) initiatives and underground hydrogen storage enabling large-scale, long-duration energy storage for renewable energy integration. This review examines the opportunities and challenges associated with the geological storage of CO₂ and hydrogen, emphasizing the geological, technical, environmental, and regulatory factors that govern storage performance and long-term security. The suitability of major storage formations, including deep saline aquifers, depleted oil and gas reservoirs, and salt caverns, is discussed in relation to reservoir characteristics, containment mechanisms, and operational requirements. The review further evaluates the contribution of subsurface storage to climate change mitigation, decarbonization of hard-to-abate sectors, and stabilization of future hydrogen-based energy systems. Key challenges, including leakage risks, geomechanical instability, geochemical and microbial interactions, uncertainty in reservoir characterization, monitoring requirements, and regulatory constraints, are critically assessed. Recent advances in reservoir modeling, real-time monitoring technologies, and integrated risk assessment are highlighted as important enablers for improving storage reliability and public confidence. The review also identifies emerging opportunities for integrating CO₂ sequestration and underground hydrogen storage within shared geological infrastructure to enhance resource utilization and accelerate the energy transition. Finally, priority research directions are outlined to address remaining scientific and engineering uncertainties. By providing a concise synthesis of current knowledge and future perspectives, this review offers a comprehensive resource for researchers, industry practitioners, and policymakers working to advance secure and sustainable subsurface energy storage as a cornerstone of global decarbonization strategies.

Keywords: Subsurface energy storage, Carbon dioxide, Hydrogen, Carbon capture and storage (CCS), Energy transition, Reservoir integrity.