Hybrid Thermal and Mechanical Storage Systems

Detailed overview of innovation with sample startups and prominent university research


What it is

Hybrid thermal and mechanical storage systems combine different energy storage technologies, such as thermal energy storage (TES) and mechanical energy storage (MES), to create systems with improved performance characteristics and greater flexibility. This approach leverages the strengths of each technology to address the diverse needs of energy storage applications.

Impact on climate action

Hybrid Thermal and Mechanical Storage Systems in Thermal & Mechanical Storage optimize renewable energy integration by offering versatile storage solutions. By combining thermal and mechanical storage, these innovations enhance grid stability, enable load shifting, and reduce reliance on fossil fuels, accelerating the transition to a low-carbon energy system and mitigating climate change.

Underlying
Technology

  • Thermal Energy Storage (TES): TES technologies store thermal energy in various forms, such as sensible heat, latent heat, or thermochemical energy. Examples include water tanks, ice storage systems, phase change materials (PCMs), and thermochemical materials.
  • Mechanical Energy Storage (MES): MES technologies store energy in the form of kinetic energy or potential energy. Examples include flywheels, compressed air energy storage (CAES), and pumped hydro storage.
  • Hybrid System Design: Hybrid systems combine TES and MES technologies in various configurations to achieve specific performance goals. This can involve using TES to store heat generated by a mechanical system, or using MES to provide power for a heat pump that charges a TES system.
  • Control Systems: Advanced control systems manage the operation of the hybrid system, optimizing energy flows between different components and ensuring efficient energy storage and retrieval.

TRL : 5-7

Prominent Innovation themes

  • Hybrid TES-CAES Systems: These systems combine compressed air energy storage with thermal energy storage, using the heat generated during air compression to improve the efficiency of the system.
  • Hybrid TES-Flywheel Systems: These systems combine flywheels with thermal energy storage, using the flywheel to provide power for a heat pump that charges a TES system.
  • Hybrid TES-Pumped Hydro Storage: This approach combines pumped hydro storage with TES to improve the efficiency and flexibility of the system.
  • AI-Powered Hybrid System Optimization: AI and machine learning algorithms can be used to optimize the operation of hybrid systems, predicting energy demand and supply, and managing energy flows between different components.

Other Innovation Subthemes

  • District Heating and Cooling Applications
  • Advanced Control Algorithms
  • Long-Duration Energy Storage Solutions
  • Smart Grid Integration
  • Waste Heat Recovery Systems
  • Closed-Loop Thermodynamic Cycles
  • Grid-Scale Energy Storage
  • Thermal Energy Conversion Efficiency
  • Hybrid System Flexibility
  • Energy Demand Prediction
  • Heat Pump Integration
  • Energy Storage Optimization
  • Hybrid System Scalability
  • Industrial Process Heat Applications
  • Round-Trip Efficiency Improvement
  • Thermal and Mechanical Energy Synergy

Sample Global Startups and Companies

  1. Malta Inc.:
    • Technology Enhancement: Malta Inc. focuses on developing innovative grid-scale energy storage solutions based on a combination of thermal and mechanical energy storage technologies. Their system utilizes reversible heat pumps and heat exchangers to convert electricity into thermal energy, which is stored in molten salt or other phase-change materials. The stored thermal energy can then be converted back into electricity using a steam turbine or other thermal generators when needed.
    • Uniqueness of the Startup: Malta Inc. stands out for its hybrid approach to energy storage, which combines the benefits of thermal and mechanical storage technologies. By leveraging both heat-based and kinetic energy storage principles, their system offers high energy density, rapid response times, and long-duration storage capabilities, making it suitable for balancing renewable energy sources and enhancing grid stability.
    • End-User Segments Addressing: Malta Inc. serves utilities, independent power producers (IPPs), and renewable energy developers seeking cost-effective and scalable energy storage solutions. Their hybrid thermal and mechanical storage systems are deployed in utility-scale solar and wind farms, microgrids, and grid ancillary service markets, supporting the integration of renewable energy and grid reliability.
  2. Echogen Power Systems:
    • Technology Enhancement: Echogen Power Systems specializes in advanced thermal energy storage and power generation solutions. Their hybrid systems integrate thermal storage technologies such as molten salt or phase-change materials with advanced heat engines or turbines. This allows for efficient and flexible energy storage and dispatch, enabling grid operators to balance supply and demand while reducing reliance on fossil fuels.
    • Uniqueness of the Startup: Echogen Power Systems stands out for its expertise in high-temperature thermal energy storage and its focus on hybridizing thermal storage with innovative power generation technologies. Their systems offer high efficiency, scalability, and modularity, making them suitable for a wide range of applications, including renewable energy integration, industrial process heat, and waste heat recovery.
    • End-User Segments Addressing: Echogen Power Systems serves utility companies, industrial facilities, and renewable energy developers seeking reliable and cost-effective energy storage solutions. Their hybrid thermal and mechanical storage systems are deployed in diverse settings, including concentrated solar power plants, cogeneration facilities, and energy-intensive industries, providing on-demand power and thermal energy.
  3. Energy Dome:
    • Technology Enhancement: Energy Dome specializes in modular and scalable energy storage solutions based on a combination of thermal and mechanical storage technologies. Their system employs a dome-shaped structure to store both thermal and kinetic energy, utilizing phase-change materials and flywheels for energy storage and conversion. This allows for rapid charging and discharging cycles, as well as high energy density and reliability.
    • Uniqueness of the Startup: Energy Dome stands out for its innovative approach to hybrid energy storage using a dome-shaped architecture. Their system offers advantages in terms of scalability, modularity, and cost-effectiveness compared to traditional storage technologies. By integrating thermal and mechanical storage principles, Energy Dome provides a versatile and adaptable solution for grid-scale energy storage applications.
    • End-User Segments Addressing: Energy Dome serves utility companies, microgrid operators, and renewable energy developers seeking flexible and resilient energy storage solutions. Their hybrid thermal and mechanical storage systems are deployed in various settings, including remote communities, industrial parks, and renewable energy projects, supporting grid stability and renewable energy integration.

Sample Research At Top-Tier Universities

  1. Massachusetts Institute of Technology (MIT):
    • Research Focus: MIT is at the forefront of research on Hybrid Thermal and Mechanical Storage Systems, focusing on integrating thermal and mechanical energy storage technologies to improve overall system efficiency, flexibility, and reliability.
    • Uniqueness: Their research involves the development of innovative hybrid storage architectures that combine thermal storage mediums, such as phase change materials or molten salts, with mechanical storage systems, such as compressed air or flywheel energy storage. These hybrid systems aim to leverage the complementary advantages of both storage technologies to optimize energy conversion and storage in various applications.
    • End-use Applications: The outcomes of their work have applications in renewable energy integration, grid stabilization, and industrial process heating and cooling. By developing hybrid thermal and mechanical storage solutions, MIT’s research contributes to enhancing energy resilience, reducing greenhouse gas emissions, and promoting the widespread adoption of renewable energy technologies.
  2. National Renewable Energy Laboratory (NREL):
    • Research Focus: NREL conducts cutting-edge research on Hybrid Thermal and Mechanical Storage Systems, leveraging its expertise in renewable energy technologies, grid integration, and energy storage to develop advanced hybrid storage solutions for a wide range of applications.
    • Uniqueness: Their research encompasses the characterization, modeling, and optimization of hybrid storage systems, considering factors such as cost, performance, and scalability. They also evaluate the techno-economic feasibility and environmental impact of hybrid storage technologies under different operating conditions and market scenarios.
    • End-use Applications: The outcomes of their work find applications in utility-scale renewable energy projects, microgrid systems, and off-grid electrification initiatives. By advancing hybrid thermal and mechanical storage technologies, NREL’s research supports the transition to a more resilient, sustainable, and decentralized energy infrastructure.
  3. Technical University of Munich (TUM):
    • Research Focus: TUM is engaged in innovative research on Hybrid Thermal and Mechanical Storage Systems, leveraging its interdisciplinary research capabilities in engineering, materials science, and renewable energy to develop novel storage concepts and system architectures.
    • Uniqueness: Their research involves the design, optimization, and testing of hybrid storage prototypes using state-of-the-art simulation tools and experimental facilities. They explore innovative heat transfer fluids, thermal energy conversion devices, and mechanical storage components to enhance system efficiency, durability, and performance.
    • End-use Applications: The outcomes of their work have applications in district heating and cooling systems, industrial process optimization, and solar power plants. By developing hybrid thermal and mechanical storage solutions, TUM’s research contributes to energy efficiency improvements, cost reductions, and carbon footprint reductions in various sectors.

commercial_img Commercial Implementation

Hybrid thermal and mechanical storage systems are still in the early stages of commercial deployment, with a limited number of pilot projects and demonstration plants in operation. However, the technology is gaining increasing interest as a potential solution for long-duration energy storage and grid-scale applications.