Discover the three types of thermal energy storage systems

The different types of thermal energy storage systems have a crucial role to play in the current context. 

As the energy transition towards sustainable, renewable energy sources takes place, operators and engineers are facing the uncertainty of several renewable energy sources which, by nature, are intermittent. Such is the well-known case of both solar and wind energy sources, among others.

There are several technologies facilitating the incorporation of these sources. This includes the increasingly demanded industrial heat pumps, which are able to efficiently enhance low-grade heat to substantial heat. 

On the other hand, the three main types of thermal energy storage systems are also playing a key role in the efficient use of renewable energy sources. Let’s see how.

What are thermal storage systems

Thermal storage systems (also known as TES, for thermal energy storage) include all technologies that allow the capture and storage of thermal energy for later use. 

The three types of thermal energy storage systems  allow excess heat (or cooling) produced during periods of low demand to be stored for later use during periods of high demand. As such, during peak demand periods which could find a system struggling to meet the instantaneous demand, thermal storage systems can provide an additional source. This load shifting helps balance the supply and demand of heating and cooling, ensuring continuous supply.

Another key use of TES systems is their capacity to enable the integration of intermittent renewable energy sources by storing excess energy for use when renewable generation is not available.

Today, the importance of these systems is playing a crucial role in balancing energy supply and demand and optimizing energy utilization. In fact, TES technologies have been facilitating the implementation of the multiple uses of thermal energy.

As such, thermal storage systems offer several advantages in terms of improved energy efficiency and the ability to integrate with renewable energy sources.

The types of thermal energy storage systems

Sensible Heat Storage

Sensible heat storage systems are able to store thermal energy by changing the temperature of a storage medium, through the use of materials such as water, rocks, or ceramics, among others. In these systems, temperatures and energy remain proportional, so that the more energy is put in a material, the higher its temperature.

Sensible heat TES storage is often found in systems such as hot water storage tanks, concrete thermal mass systems, and molten salts. Its 

Latent Heat Storage

Latent heat TES systems are able to store thermal energy by exploiting the heat that is absorbed or released during a phase change of a material (that is, during the transition from gas to liquid or from liquid to a solid). 

In order to generate latent heat storage, phase change materials (PCMs) are commonly used. These materials are able to absorb or release large amounts of heat during the phase transition (e.g., solid to liquid or liquid to gas), enabling efficient energy storage and release. Some common PCM materials include paraffin wax, salt hydrates and certain organic compounds.

Some common applications of latent heat storage include ice storage systems, where water freezes during periods of low energy demand and melts to release cooling during peak demand periods.

Typically, energy stored in latent heat transitions is higher than that of sensible heat systems. For instance, in the case of water, melting it can provide approximately 80 times more energy than rising its temperature from 1 to 2 degrees.

Thermochemical Storage

Thermochemical storage systems store thermal energy by employing reversible chemical reactions that involve heat absorption or release. 

This involves the use of materials that can undergo a chemical reaction to store energy and then release it when the reaction is reversed. Some common thermochemical materials include metal hydrides, metal oxides, and certain salts. 

In other words, thermochemical systems are able to store heat through reversible chemical reactions, upon the combination or separation of two substances that make heat be absorbed or released.

Among the three types of thermal energy storage systems, thermochemical storage has the potential to store and release large amounts of energy, making it suitable for high-temperature applications. In fact, they present a superior energy density and an absence of energy leakage.

Apart from these benefits regarding high energy density, thermochemical storage also presents long-term storage capability, and the ability to release heat at a constant temperature.

These properties make this model suitable for applications where high-temperature heat storage is required, and where the stored energy needs to be readily released for specific purposes. 

All in all, TES systems are at the forefront of innovation in energy and heating engineering, providing state-of-the-art solutions for more efficient systems.

Such is the case of ARANER’s Thermal Storage Tanks. These accumulators are able to store available thermal energy to be used in a later stage when consumption is required or when energy generation is cheaper. 

Through the use of a TES tank, it’s possible to reduce the operational cost of projects as well as the required capacity of Cooling and Heating plants, increasing the efficiency and reducing the capital cost.

The implementation process for a successful thermal storage system  must involve an adequate design process that takes each project’s needs into account. This is where our expertise at ARANER comes in.

Through our TES solutions, we strive to help operators and designers make the most of the uses of thermal energy.

The Farah Hospital, located in Amman, represents a key example of our commitment for innovation and efficiency in thermal energy. One of the largest and most prestigious hospitals in the Middle East, their planned expansion involved a quest for modern, efficient and sustainable structures to thermal energy. In fact, the project set out to qualify for a LEED Certification for Green Building. 

At a time when the standard solution typically involved the installation of diesel boilers and electrical chillers, at ARANER we went a step further. 

The installation of a  a 1,280 TR· h Thermal Energy Storage Tank (coupled with 3,300 kW highly-efficient industrial Heat Pumps) allowed the project to achieve maximum efficiencies and sustainability.

Likewise, we were also in charge of ensuring the world-famous Qatar Football stadium had their own efficiency goals met. At ARANER, we installed a  naturally-stratified 30,000 TR·h TES tank able to meet peak load demands, accommodate small load variations and act as a backup for chillers.

Want to learn more about the three types of thermal energy storage systems and how to determine which model is adequate for your project? Get in touch with us and speak with our team about your needs and how we can help you achieve your goals.