What are the applications of thermal energy storage?

Thermal energy storage (TES) systems are versatile technologies designed to store heat or cold for later use, playing a pivotal role in enhancing energy efficiency and stability across diverse sectors. These systems are crucial for managing energy supply and demand, integrating renewable energy sources, and optimizing industrial processes.

Key Applications of Thermal Energy Storage

Thermal energy storage finds a wide array of applications, particularly in large-scale scenarios where managing energy flow efficiently is critical. According to Advances in thermal energy storage: Fundamentals and applications, "Large-scale applications such as power plants, geothermal energy units, nuclear plants, smart textiles, buildings, the food industry, and solar energy capture and storage are ideal candidates for TES systems."

Let's explore these and other significant applications in detail:

1. Energy Production and Management

TES systems are integral to improving the efficiency and flexibility of energy generation facilities, allowing for better management of fluctuating energy demands.

• Power Plants (Conventional & Nuclear):
  • Peak Shaving: TES helps conventional power plants store excess heat generated during off-peak hours and release it during peak demand, reducing the need to fire up inefficient peaker plants.
  • Load Following: It allows plants to operate at more consistent, optimal levels by decoupling heat generation from electricity generation, improving overall efficiency and reducing wear and tear.
  • Waste Heat Recovery: Capturing and storing waste heat from industrial processes or power generation significantly enhances energy recovery.
• Geothermal Energy Units:
  • Consistent Output: Geothermal plants can use TES to store excess heat when demand is low, ensuring a more consistent and dispatchable power output even if the geothermal resource flow varies slightly.

2. Renewable Energy Integration

TES is fundamental to overcoming the intermittent nature of many renewable energy sources, ensuring a stable and reliable power supply.

• Solar Energy Capture and Storage:
  • Concentrated Solar Power (CSP): TES is essential for CSP plants, storing solar heat in molten salts or other media to generate electricity even after sunset or during cloudy periods, making solar power dispatchable.
  • Solar Water Heating: Stores solar-heated water for domestic or commercial use, reducing reliance on conventional heating.
• Wind Energy:
  • While not directly storing wind, TES can store excess electricity generated by wind farms as heat (e.g., in electric boilers or resistance heaters) for later use, preventing curtailment and improving grid stability.

3. Built Environment

Buildings, both commercial and residential, leverage TES for efficient heating, cooling, and domestic hot water supply.

• Heating and Cooling:
  • Thermal Comfort: Storing chilled water or ice at night (when electricity is cheaper) to cool buildings during the day, or storing heat for space heating, significantly reduces energy costs and peak electricity demand.
  • District Heating/Cooling: Centralized TES systems can serve multiple buildings, enhancing efficiency and reducing the carbon footprint of urban areas.
• Domestic Hot Water: Residential TES units store hot water, often heated by solar thermal collectors or off-peak electricity, providing a continuous supply.

4. Industrial Processes

Industries utilize TES to optimize various processes, improve energy efficiency, and reduce operational costs.

• Food Industry:
  • Refrigeration: Storing "coolness" (e.g., ice) for refrigeration in warehouses or during transportation.
  • Process Heating/Cooling: Utilizing stored heat for sterilization, pasteurization, drying, or cooling processes, leading to more stable operating temperatures and reduced energy consumption.
• Other Industries: Applications in pulp and paper, chemical, and metal industries for heat recovery, process optimization, and reducing energy intensive operations during peak hours.

5. Advanced and Niche Applications

TES technology is also paving the way for innovative applications that enhance personal comfort and specialized needs.

• Smart Textiles:
  • Personal Thermal Management: Integrating phase change materials (PCMs) into fabrics can absorb or release heat to maintain comfortable body temperatures for the wearer, ideal for sportswear, medical textiles, or protective gear.

Summary of Applications

The following table summarizes the key applications of thermal energy storage:

Thermal energy storage systems are vital for transitioning to a more sustainable and resilient energy future by providing flexibility, efficiency, and reliability across a broad spectrum of applications.