The transition to a lower-carbon industrial sector is not only about replacing one fuel with another. A large share of industrial energy use is heat: raising the temperature of a process, maintaining it, recovering heat that would otherwise be wasted, and providing cooling when needed. Managing that heat efficiently is therefore an important part of industrial decarbonisation.
GeoS-TECHIS, an EU-funded Horizon Europe project, is looking at industrial heat as an interconnected system: how it is produced, moved, stored and used. The project focuses on industrial processes requiring heat below 200 °C and cooling above 0 °C, where fossil fuels still play a significant role.
The GeoS-TECHIS approach brings together medium-temperature geothermal resources, high-temperature heat pumping, heat-driven cooling and thermal energy storage. Thermal storage is particularly important because energy supply and industrial demand do not always occur at the same time. Being able to store heat and use it when it is needed can help make better use of available geothermal energy.
But an effective storage system depends on more than the storage unit itself. The fluid carrying heat through the system also matters.
The fluid behind the heat
Heat transfer fluids play a crucial role in thermal energy storage. Their properties influence how effectively heat can be transferred into and out of storage, how much energy is required to circulate the fluid, and how reliably the system can operate over time.
Within GeoS-TECHIS, LEITAT Technological Center leads Work Package 3 and is developing an advanced heat transfer nanofluid designed to improve thermal performance within the storage system.
The research includes formulation and laboratory characterisation, looking at properties such as thermal behaviour, stability and compatibility with materials that could be used within the system. The nanofluid has been formulated and characterised, and work is continuing to integrate its properties into the thermal storage model.
Environmental considerations are also being incorporated into the development process. LEITAT is assessing aspects such as biodegradability and aquatic ecotoxicity under defined laboratory conditions, while compatibility testing is helping researchers understand how the fluid interacts with materials used in the system.
This allows technical and environmental considerations to inform the development process together rather than treating environmental performance as something to be considered only after the technology has been developed.
Looking beyond technical performance
A fluid can perform well in the laboratory while being part of a wider system with environmental impacts arising elsewhere, for example from infrastructure, resource consumption or the electricity required to meet industrial thermal demand.
This is where Life Cycle Assessment, or LCA, becomes important.
LCA provides a structured way of examining where environmental impacts may arise across a technology or system. Within GeoS-TECHIS, LEITAT WP6 leadership is using this approach to assess the wider environmental performance of the solutions being developed and to identify areas where impacts may be most significant.
Early assessment work has highlighted infrastructure, resource inputs and electricity consumption associated with industrial thermal demand as areas that deserve particular attention as the technology and system design continue to develop.
Importantly, the assessment looks beyond carbon emissions alone. The research team is applying 16 environmental impact indicators including carbon footprint, resource use, water consumption, acidification, and ecotoxicity (among others) to evaluate the system across its full lifecycle.
This broader perspective matters because reducing greenhouse gas emissions in one part of a system should not unintentionally create significant impacts elsewhere. Identifying these environmental hotspots during development gives researchers an opportunity to understand potential trade-offs and consider where improvements could have the greatest effect.
Adding the societal perspective
Engineering responsibility also extends beyond environmental performance.
Alongside the environmental assessment, GeoS-TECHIS is developing a social life cycle assessment to consider potential societal impacts. Data collection is underway, while project partners are also engaging stakeholders and the public on geothermal energy and its potential industrial applications.
This is particularly relevant for geothermal technologies. Heat beneath the ground is a valuable energy resource, but deploying geothermal solutions also involves industries, communities, regulators and other stakeholders. Understanding their perspectives is therefore an important part of developing solutions that can ultimately move beyond research and into practical use.
This holistic approach relies on close consortium collaboration. While LEITAT advances the nanofluid formulation and leads integrated environmental and societal assessments, researchers at the University of Ljubljana lead the physical engineering of the thermal energy storage system itself.
Bringing these areas together allows storage design, fluid performance and wider environmental and societal considerations to develop alongside one another.
Engineering responsibility from the start
The next stage of the work will increasingly connect these different elements. The properties of the heat transfer fluid will be represented within the thermal storage model, while environmental and societal assessments will continue to evolve as more project data become available.
Ultimately, engineering responsibility in GeoS-TECHIS means looking beyond whether an individual technology works. It means understanding how components perform together, what resources they require, where environmental impacts may arise and how future solutions could affect the industries and communities that use them.
By bringing heat-transfer research and life cycle thinking together during development, GeoS-TECHIS is working towards geothermal heating, cooling and storage solutions that are technically effective while taking their wider environmental and societal impacts into account.
Find out more
Explore how GeoS-TECHIS is supporting the development of industrial geothermal solutions across Europe. Visit the GeoS-TECHIS website for project updates, blogs and publicly available resources.
GeoS-TECHIS has received funding from the European Union’s Horizon Europe research and innovation programme under Grant Agreement No. 101172928. Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union or CINEA. Neither the European Union nor the granting authority can be held responsible for them.
Let’s shape a sustainable tomorrow!
The GeoS-TECHIS Team
