Advances in Geothermal and Subsurface Energy Storage Systems

Dear Colleagues,

The global transition toward a low-carbon and sustainable energy future requires innovative solutions for reliable, efficient and long-term energy supply and storage. Among the most promising approaches, geothermal energy and subsurface energy storage systems are gaining renewed attention as key enablers of the clean energy transition. These systems can provide baseload renewable heat and power, facilitate seasonal thermal energy storage and support the decarbonization of heating, cooling and electricity sectors.

Recent advances in geoscience, reservoir engineering, drilling technologies and monitoring methods have expanded the potential of geothermal and subsurface energy applications—from conventional hydrothermal resources to enhanced geothermal systems (EGS), underground thermal energy storage (UTES) and integrated energy networks. At the same time, growing concerns about sustainability, social acceptance and environmental impact are guiding research toward safer, more efficient and publicly accepted designs.

This Special Issue aims to present and disseminate the latest research and technological developments in geothermal energy and subsurface energy storage, with a focus on sustainable design, system optimization and societal integration. We invite contributions that explore both fundamental scientific advances and applied innovations enabling resilient, carbon-neutral energy systems.

Topics of interest for publication include, but are not limited to:

• Advances in geothermal resource exploration, characterization and modeling
• Enhanced geothermal systems (EGS) and deep geothermal technologies
• Underground thermal energy storage (ATES, BTES, CTES) and hybrid systems
• Coupled modeling of heat, fluid flow and geo-mechanical processes
• Materials and engineering challenges for high-temperature and high-pressure environments
• Integration of geothermal and subsurface storage into district heating and cooling networks
• Subsurface energy systems for net-zero buildings and urban sustainability
• Environmental impact assessment and sustainability metrics
• Social acceptance, policy and governance of geothermal and subsurface energy projects
• Digitalization, data analytics and monitoring technologies for system optimization
• Techno-economic and life-cycle assessment of geothermal and storage systems
• Role of geothermal energy in renewable energy integration and carbon neutrality

We warmly invite original research papers, reviews and case studies that address these challenges and opportunities, helping to advance our collective understanding of how geothermal and subsurface energy systems can contribute to a sustainable, reliable and equitable energy future.

Dr. Mukhtar A. Kassem
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.