Geothermal Heat Storage

Detailed overview of innovation with sample startups and prominent university research

What it is

Geothermal heat storage involves capturing and storing excess geothermal energy for later use. This technology addresses the temporal mismatch between geothermal energy supply and demand, ensuring a consistent and reliable source of heat or electricity even when geothermal resource availability fluctuates.

Impact on climate action

Geothermal Heat Storage under Geothermal Energy boosts climate action by optimizing renewable energy utilization. By storing excess heat from geothermal sources, this innovation ensures uninterrupted energy supply, reduces reliance on fossil fuels, and accelerates the transition to a sustainable energy system, mitigating carbon emissions and combating climate change.


  • Thermal Energy Storage (TES) Systems: TES systems store excess geothermal heat in various media, such as water, rocks, or phase change materials.
  • Aquifer Thermal Energy Storage (ATES): ATES systems store heat or cold in underground aquifers, utilizing the natural storage capacity of these geological formations.
  • Borehole Thermal Energy Storage (BTES): BTES systems store heat or cold in vertical boreholes drilled into the ground, using the surrounding rock or soil as a storage medium.
  • Pit Thermal Energy Storage (PTES): PTES systems store heat or cold in large, insulated pits filled with water or other storage materials.
  • Thermochemical Storage: This technology utilizes reversible chemical reactions to store and release heat.

TRL : 6-8 (depending on the specific storage technology)

Prominent Innovation themes

  • Advanced TES Materials: Researchers are developing new and improved TES materials with higher heat capacity, better thermal conductivity, and longer lifespans.
  • Hybrid Geothermal-Storage Systems: Combining geothermal energy with other renewable energy sources and energy storage technologies can create hybrid systems that offer increased flexibility and reliability.
  • AI-Powered Energy Management: AI and machine learning can be used to optimize the operation of geothermal heat storage systems, predicting energy demand and optimizing charging and discharging cycles.
  • Geothermal Heat Pumps with Thermal Storage: Integrating thermal storage with geothermal heat pumps can improve system efficiency and provide a more consistent and reliable heat source for buildings.

Other Innovation Subthemes

  • Advanced Thermal Energy Storage Materials
  • Hybrid Renewable Energy Systems
  • AI-Optimized Energy Storage
  • Geothermal Heat Pump Integration
  • Closed-loop Enhanced Geothermal Systems (EGS)
  • Innovative Thermal Storage Technologies
  • Next-generation Geothermal Heat Storage
  • Geothermal Heat Storage for Industrial Processes
  • Aquifer Thermal Energy Storage (ATES) Advancements
  • Nanotechnology in Thermal Energy Storage
  • Geothermal Heat Storage in Urban Environments
  • Geothermal Energy and Hydrogen Storage
  • Geothermal Heat Storage for Off-grid Applications

Sample Global Startups and Companies

  1. Eavor Technologies:
    • Technology Enhancement: Eavor Technologies is pioneering the development of closed-loop geothermal systems, known as the Eavor-Loop™, for efficient and scalable heat storage and power generation. Their innovative approach involves drilling deep wells to circulate a working fluid through a subsurface network of connected loops, capturing heat from the earth’s interior and transferring it to the surface for various applications.
    • Uniqueness of the Startup: Eavor Technologies stands out for its closed-loop geothermal system, which eliminates the need for hydraulic fracturing and mitigates environmental risks associated with traditional geothermal projects. Their solution offers a reliable and renewable source of heat and power with minimal surface footprint, making it suitable for urban areas and industrial applications.
    • End-User Segments Addressing: Eavor Technologies serves utilities, industrial facilities, and communities seeking sustainable and cost-effective heat and power solutions. Their closed-loop geothermal technology can be deployed in district heating systems, greenhouse operations, and industrial processes, providing reliable and emissions-free energy.
  2. Fervo Energy:
    • Technology Enhancement: Fervo Energy specializes in advanced geothermal development techniques, including enhanced geothermal systems (EGS) and deep direct-use (DDU) applications for geothermal heat storage. Their approach involves drilling deep wells to access hot rock formations, utilizing advanced reservoir engineering and stimulation techniques to enhance heat extraction and storage capabilities.
    • Uniqueness of the Startup: Fervo Energy stands out for its focus on unlocking the potential of deep geothermal resources for heat storage and power generation. Their innovative techniques enable the cost-effective deployment of geothermal projects in regions with limited traditional geothermal resources, expanding the reach of clean and renewable energy.
    • End-User Segments Addressing: Fervo Energy serves utilities, municipalities, and industrial clients seeking reliable and low-carbon heat and power solutions. Their advanced geothermal systems can be deployed in district heating networks, industrial processes, and power generation facilities, displacing fossil fuels and reducing greenhouse gas emissions.
  3. Storengy:
    • Technology Enhancement: Storengy, a subsidiary of ENGIE, specializes in underground natural gas storage and geothermal energy solutions. They offer expertise in geothermal heat storage and seasonal thermal energy storage (STES) systems, leveraging underground reservoirs and aquifers to store heat and cold for various applications.
    • Uniqueness of the Startup: Storengy stands out for its integrated approach to geothermal heat storage and energy management, leveraging existing infrastructure and geological formations for efficient heat storage and exchange. Their solutions enable the decarbonization of heating and cooling systems, contributing to energy transition goals and climate resilience.
    • End-User Segments Addressing: Storengy serves utilities, municipalities, and industrial customers seeking sustainable and resilient heat and cooling solutions. Their geothermal heat storage systems can be deployed in district heating networks, residential buildings, and industrial processes, providing reliable and emissions-free thermal energy.

Sample Research At Top-Tier Universities

  1. Technical University of Munich (TUM):
    • Research Focus: TUM is a prominent research institution in the field of geothermal energy, with a focus on developing innovative solutions for geothermal heat storage. Their research involves investigating advanced underground thermal energy storage (UTES) systems, including borehole thermal energy storage (BTES) and aquifer thermal energy storage (ATES), for storing excess heat from geothermal sources.
    • Uniqueness: TUM’s research emphasizes the optimization of heat transfer processes, material selection, and system design to maximize the efficiency and reliability of geothermal heat storage systems. They explore novel approaches for enhancing thermal conductivity, thermal cycling performance, and long-term stability of underground reservoirs to enable cost-effective and scalable deployment of geothermal heat storage technologies.
    • End-use Applications: The outcomes of their work have applications in district heating and cooling, industrial process heat, and renewable energy integration. By leveraging geothermal heat storage, TUM’s research contributes to reducing greenhouse gas emissions, enhancing energy security, and promoting the transition to a sustainable and low-carbon energy system.
  2. Massachusetts Institute of Technology (MIT):
    • Research Focus: MIT is at the forefront of research on Geothermal Heat Storage, focusing on developing advanced materials, modeling techniques, and monitoring technologies for optimizing the performance and reliability of geothermal reservoirs and heat exchange systems.
    • Uniqueness: Their research encompasses the development of novel heat storage materials, such as phase change materials (PCMs), thermochemical storage media, and high-temperature heat exchangers, for storing and releasing thermal energy efficiently. They also employ advanced numerical simulations, machine learning algorithms, and sensor networks to predict reservoir behavior, optimize operation strategies, and mitigate operational risks in geothermal heat storage projects.
    • End-use Applications: The outcomes of their work find applications in geothermal power generation, district heating networks, and industrial process optimization. By advancing geothermal heat storage technologies, MIT’s research enables the utilization of geothermal resources for baseload power production, grid stabilization, and thermal energy management in diverse sectors.
  3. Stanford University:
    • Research Focus: Stanford University conducts innovative research on Geothermal Heat Storage, leveraging its expertise in subsurface engineering, geophysics, and renewable energy systems to develop integrated approaches for geothermal energy utilization and storage.
    • Uniqueness: Their research involves the development of advanced geophysical imaging techniques, reservoir modeling frameworks, and optimization algorithms for characterizing subsurface properties, optimizing injection and production strategies, and assessing the feasibility of geothermal heat storage projects. They also investigate the synergies between geothermal heat storage, enhanced geothermal systems (EGS), and other renewable energy technologies to maximize overall system efficiency and economic viability.
    • End-use Applications: The outcomes of their work have applications in energy storage, grid stability, and climate mitigation. By pioneering research on geothermal heat storage, Stanford’s research contributes to expanding the role of geothermal energy in the global energy mix, diversifying renewable energy options, and facilitating the transition to a sustainable and resilient energy future.

commercial_img Commercial Implementation

Geothermal heat storage is being implemented in various applications around the world, including district heating systems, greenhouses, and industrial processes. For example, several district heating systems in Europe utilize aquifer thermal energy storage to store excess heat from geothermal sources and release it during peak demand periods.