Extremadura has taken another step in its commitment to energy storage with a cross-border project that proposes reusing old grain silos as thermal batteriesThe idea is to take advantage of these disused infrastructures to store surplus renewable electricity in the form of heat, which would otherwise go to waste.
The initiative, named THESILOIt will be developed in the EUROACE cooperation region, which includes Extremadura along with the Alentejo and Central Portugal, and is conceived as a testing ground to demonstrate that the conversion of these silos can serve both to improve energy management and to revitalize the rural environment.
A cross-border project to give new life to silos
The THESILO project aims rehabilitate disused grain silos and transform them into thermal storage systems capable of accumulating renewable energy in the form of heat. This will be achieved using sustainable and recycled materials, ensuring the model meets European environmental requirements and reduces the overall carbon footprint of the system.
The performance is integrated into the Interreg VI-A Spain-Portugal Cooperation Program (POCTEP) 2021-2027, one of the European Union's main instruments for financing joint projects between border regions. In this case, the scope of work focuses on the EUROACE territory, where around 1.050 out-of-use grain silos which could become a distributed storage network.
With a total budget of 1.514.396 EurosTHESILO aims to become a benchmark for thermal energy storage solutions linked to renewables on a regional scale. The project seeks to demonstrate that these old agricultural infrastructures can be converted into strategic energy assets, with applications in nearby productive sectors, such as the agri-food industry.
The regional administration emphasizes that this type of initiative fits with the European roadmap for ecological transition, which calls not only for more renewable energy, but also new ways of storing and managing production when generation exceeds instantaneous demand.
The Iberian Centre for Research in Energy Storage at the forefront
The project coordination is the responsibility of Iberian Centre for Research in Energy Storage (CIIAE), an entity based in Extremadura specializing in energy storage technologies. From this center, both the technical design of the solutions and the collaboration between the various Spanish and Portuguese partners will be piloted.
Along with the CIIAE, the following participate: Extremadura Energy Agency (AGENEX), the Alentejo Energy Agency (AreanaTejo), the Polytechnic of Portalegre, the Institute of Construction, Energy, Environment and Sustainability (ITECONS) and the Adai entity, in addition to several centers integrated into the Extremadura System of Science, Technology and Innovation (SECTI), among which is INTROMAC, specializing in ornamental rocks and building materials.
This collaborative network strengthens the scientific and technological aspects of the project, combining the expertise of research centers, public administrations, and entities dedicated to energy management. According to the Regional Government of Extremadura, it involves strengthen cross-border cooperation in the area of ​​innovation and increasing the capacity to attract competitive European funds.
The Secretary General of Science, Technology and Innovation, Javier de Francisco MorcilloExtremadura has established itself as one of the most active regions in securing EU funding for R&D projects with Portugal. Data from the CDTI (Center for the Development of Industrial Technology) indicates that, between 2021 and 2025, the region has obtained more than double the resources from Horizon Europe than in the entire period from 2014 to 2020.
The regional administration interprets these figures as a sign that the strategy of forging scientific alliances on both sides of the border is bearing fruit and that projects like THESILO are proving successful. They reinforce that dynamic of stable cooperation between research groups and public entities.
Torremocha, laboratory for the first thermal battery in a silo
The first practical step of the project will take place in the municipality of Cáceres. Torremochawhere the local silo will become an experimental pilot site. The official presentation took place at the town's House of Culture, in an event where the Regional Government detailed the main lines of work and the approximate timelines for launching the trial.
In this silo, the following will be checked: actual efficiency of thermal storage systems designed within the framework of THESILO. The objective is to monitor how the chosen materials behave, their heat storage capacity, the degree of energy losses, and the system's response to different loading and unloading patterns.
The Torremocha experience will serve as a demonstrator to assess the potential replication of the solution in other municipalities in the region and throughout the EUROACE area. If the results are satisfactory, the idea is to direct the technology towards its use in agri-food industries and local small businesses that can benefit from a more efficient and stable thermal supply.
The project has the support of the Torremocha City Council, headed by the mayor. Isabel Faustina PalominoThe collaboration of the council is considered key to facilitating the adaptation of the municipal silo and communication with the local population. The regional government has expressly thanked the council for its involvement in a program that, in addition to its technological component, aims to have a direct impact on the municipality.
The institutions involved maintain that this type of pilot program allows for first-hand detection technical, administrative and social barriers that can arise when it comes to converting existing infrastructures, from urban planning procedures to issues of industrial safety or citizen acceptance.
Work phases: from silo selection to regulatory analysis
THESILO has been structured in several stages to systematically address all aspects involved in transforming a grain silo into a thermal battery. The first phase involves the selection and structural evaluation of silosanalyzing their condition, capacity and construction conditions to determine which ones are suitable for conversion.
Once the candidates have been identified, the adaptation of the structures will begin, including reinforcing any parts that require it and incorporating the necessary connections to the electrical grid and the renewable energy generation systems that will power the thermal battery. The integration of the measurement and control equipment will also be considered at this stage.
In parallel, a work block will be developed focusing on the research and optimization of materials for heat storage. The goal is to find combinations that offer high thermal capacity, long-term stability, low cost, and good compatibility with the interior of silos, prioritizing the use of recycled or locally sourced materials whenever possible.
Based on that, the project partners will design and integrate Power-to-Heat (P2H) conversion systemsThat is, technologies capable of transforming surplus electricity from renewable sources into storable thermal energy. Different configurations will be studied to maximize overall efficiency and adapt them to different silo sizes and consumption needs.
Following the installation of the equipment and the start-up of the pilot project, a phase of validation and monitoringThis study will gather data on the system's actual performance. This information will then be used to prepare a regulatory, environmental, and techno-economic analysis that will assess the feasibility of extending the model to other parts of the region and, potentially, to other areas of Spain and Europe.
Rural impact, employment and knowledge transfer
Beyond the purely technological aspect, THESILO is conceived as a tool for revitalize rural communities who have seen many of their silos abandoned with the transformation of the agricultural sector. Reusing these infrastructures for energy storage opens the door to new uses that can generate economic activity and employment opportunities.
The Regional Government of Extremadura links the project with the Business Growthespecially in sectors such as agri-food and Automation in agriculturewhich could benefit from a cheaper and more stable heat supply, for example, for drying, pasteurization, or climate control processes in facilities. Potential synergies with small industries, cooperatives, and municipal services are also highlighted.
From a scientific perspective, the initiative aligns with the European requirement that research results translate into a knowledge transfer with rapid socio-economic impactThe idea is that what is learned in the laboratory will be applied to real-world projects on the ground, and from there, solutions can be scaled up to other territories with similar characteristics.
The exchange between research groups in Extremadura and Portugal is considered a central element of the project. This interaction allows for the sharing of methodologies, data, and experiences, enriching both regions and facilitating the development of new joint proposals in the field of energy and climate.
The regional administration insists that cross-border cooperation not only helps to attract more European funds, but also consolidates a stable network of centers and work teams that can react quickly to new calls and technological challenges related to the energy transition.
Overall, THESILO is presented as a pilot project that combines the reuse of agricultural infrastructure, innovation in thermal storage, and Spanish-Portuguese collaboration, with the aim of transforming old silos into allies for the integration of renewables, boosting local business, and strengthening the role of Extremadura and EUROACE as a laboratory for sustainable energy solutions.
