In a global context where the reduction of greenhouse gas emissions and the efficient use of energy resources are a priority, thermal energy storage and conversion emerges as a crucial technology as well as its subsequent conversion.

Focusing on the storage part, we find different technologies grouped within this field that involve the capture of heat or cold for later use. This can be achieved through different methods, such as sensible heat storage, latent heat storage and thermochemical storage.

Each of these methods has its own advantages and specific applications. For example, sensible heat storage relies on the ability of certain materials to store heat when heated, while latent heat storage takes advantage of phase changes in materials (such as melting and solidification) to store and release large amounts of energy. Thermochemical storage, on the other hand, uses reversible chemical reactions to store and release energy.

As far as thermal energy conversion is concerned, we are talking about a post-storage phase that consists of transforming the stored thermal energy into other useful forms of energy, such as electricity or mechanical work. This process is essential to harness the stored energy effectively, allowing its use in different applications, from electricity generation to the heating and cooling of buildings.

Increasing interest from the market and the industry

Due to its features and potential, the thermal storage market and its conversion is increasingly experiencing significant interest, driven by the aforementioned growing need for sustainable and efficient solutions for energy management. Especially considering the various industries that can benefit from the opportunities offered by this sector.

On the one hand, we find the industrial sector. Activities such as the steel, chemical and food industries require large amounts of heat to carry out their production processes. Thermal energy storage and conversion can help these industries to manage their heat needs more efficiently, reducing energy costs and carbon emissions.

Similarly, we find the energy sector. Concentrated solar power (CSP) plants and other renewable energy facilities are adopting thermal storage technologies to improve the reliability and stability of power generation. By storing excess energy generated during periods of high production, these plants can provide a steady supply of electricity even when renewable energy production is low.

On the other hand, and taking into account the desired efficiency targets, the construction industry is another area of activity in which thermal storage has an important role to play. Indeed, some of these technologies are already being used in buildings for efficient heating and cooling. New innovations such as phase change materials (PCMs), which can store and release heat, improving the energy efficiency of buildings and reducing heating and cooling costs, are already in the pipeline.

Finally, and as we have already mentioned in other blog posts, thermal storage and management is also key in future mobility models, contributing to improving energy efficiency and reducing emissions. One example is battery thermal management systems (BTMs), which are crucial for keeping electric vehicle (EV) batteries within an optimal temperature range.

Different areas of research and opportunity

In order to ensure that the field of thermal storage and conversion meets its expectations, research and development activities around these technologies focus on several key areas to maximize their potential.

Firstly, one of the main areas of current focus in the industry is the study of materials and processes for applications in thermochemical energy storage and fuel production, with a particular emphasis on green hydrogen (another major industry of the green future). The objective of this area of activity is to develop materials capable of storing and releasing energy efficiently through chemical reactions in the solid state.

On the other hand, another major area of study and development in this field is research into disruptive concepts and materials based on first- and second-order phase transitions. These materials, which change phase at certain temperatures, are highly efficient for thermal energy storage. They can be used in a wide range of applications, including heating and cooling systems, as well as in the management of thermal energy in industrial processes.

In recent years, research on physicochemical interactions at solid-liquid interfaces and the development of porous materials has also gained prominence. This is considered a very attractive field since porous materials can significantly improve the efficiency of energy storage systems by increasing the heat transfer and the interaction surface. This is why such research is essential for thermo-mechanical energy harvesting applications.

Another critical area is the development of new materials and catalytic systems for thermal energy storage, waste valorization, and sustainable fuel generation and storage. Research in ionic liquids and other advanced materials seeks to improve the efficiency of energy storage and conversion processes. Ionic liquids, due to their unique properties, offer great potential for thermal and catalytic storage applications.

Finally, and beyond research, the development of system-level applications for new thermal energy storage materials is fundamental to bring these technologies to market. At this point, work is underway to develop engineering and prototyping of integrated systems to provide practical and scalable solutions for industry. This includes the creation of thermal storage systems for residential, commercial and industrial applications, optimizing these systems to maximize their efficiency and performance.

These research and development activities (in which CIC energiGUNE is working prominently) are driving the possibilities offered by thermal storage and its conversion, contributing to a more sustainable and efficient energy industry. Advances in these areas are not only expected to improve energy efficiency and supply stability, but also to support the transition to a cleaner and more secure energy future, thus achieving the future and sustainable goals set for the coming years.