With R&D as our flag, at ENDEF we work as a world benchmark in hybrid solar technology. Orchestrated in different lines of work, our team of researchers works on the continuous improvement and adaptation of the latest technologies.

Beyond the continuous improvement of the products developed, at ENDEF we offer a wide variety of R&D services to different audiences, both public and private, depending on their needs.

For this we collaborate and work closely with universities, companies and advanced research centers, both nationally and internationally.

Work areas

Experimental testing on solar panels

In our facilities we count on several testing benches with capacity to experimentally assess the performance of photovoltaic, thermal and solar hybrid panels. These benches are fully monitored to favour the data acquisition at real time and postprocessing to evaluate both, the electrical and the thermal energy generation.

Thanks to this equipment, it is possible to obtain key technical features of solar panels, such us energy efficiencies, thermal performance parameters, stagnation temperature or other parameters of interest for the final customer.

Previous works

  • Comparison between different solar hybrid panels in a mobile bench
  • In-situ measurement of thermal and electrical power generation
  • Testing capacity of water-based and air-based collectors
  • Fixed bench for durability testing

4.0 Industry and IoT

Our team of monitoring experts allows us to update and automate the installation and commissioning of hybrid solar panels. The inclusion of sensors at strategic points in the panel allows us to obtain information about their operation in real time and in a specific application, which is used to self-regulate the installation and optimize its use.

Given the dual energy production in a hybrid panel, monitoring also allows optimizing the electricity / heat ratio given in the panel, as well as regulating the storage systems.

At EndeF we have the ability to design a customized monitoring plan based on the requirements of the facility and carry it out. We also provide storage and display of a particular server for each application, always based on free software and hardware, which allows user access from any device.

Previous works

  • Development of own software with which to regulate thermal / electrical generation.
  • Design and manufacture of hardware, generator and server maintenance.

Integration with other energy systems

The interest of hybrid solar panels lies not only in their operation alone but also in possible applications and uses of interest. For this reason, we are currently working on several projects that aim to study the operation and profitability of these systems and their integration with other energy equipment such as heat pumps, geothermal energy, absorption machines, etc.

Given our experience, EndeF is part of Task 60 – Applications of PVT systems, defined in 2018 by the International Energy Agency and which aims to study the applicability of hybrid solar panels and their integration with other energy systems.

Previous works

  • Numerical and experimental evaluation of the installation of 25 PVTs coupled with a heat pump (own installation).
  • Study of trigeneration systems with solar input for the industrial sector, solar cold systems for tertiary use.

Hybrid solar panel prototypes development

EndeF has the ability to manufacture all kinds of hybrid panels due to its experience with the field of hybrid installations and solar energy. We have a large team of engineers and well-equipped facilities located next to the offices, which allow the transmission of ideas and speeds up the start-up of prototypes.

In our factory we carry out the development of new models of hybrid panels covering all phases of the process, from design to manufacturing; by this way, the alternatives of materials, dimensions or configuration of the panel are compared with traditional designs.

Previous works

  • Integration of phase change material (PCM) within the panel. prototypes design that work with air or water.
  • Evaluation of different photovoltaic technologies with hybrid collectors.
  • Thermal transmission comparison of different heat absorbers, panel wrap design and insulation levels.
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  • RESEARCH ARTICLE: A. Coca-Ortegón, R. Simón-Allué, G. Brun, R. Villén. Operational Performance of Trigeneration PVT-Assisted Hp System. Energy & Buildings, 2023, 296, 0-16. https://doi.org/10.1016/j.enbuild.2023.113383
  • RESEARCH ARTICLE: M. Herrando, A. Coca-Ortegón, I. Guedea, N. Fueyo. Experimental validation of a solar system based on hybrid photovoltaic-thermal collectors and a reversible heat pump for the energy provision in non-residential buildings. Renewable and Sustainable Energy Reviews, 2023, 178, 0-16. https://doi.org/10.1016/j.rser.2023.113233

  • RESEARCH ARTICLE:  M. Herrando,  G. Fantoni,  A. Cubero, R. Simón-Allué, I. Guedea, N. Fueyo. Numerical analysis of the fluid flow and heat transfer of a hybrid PV-thermal collector and performance assessment. Renewable Energy 209 (2023). https://doi.org/10.1016/j.renene.2023.03.125
  • RESEARCH ARTICLE: R. Simón-Allué, R. Villén, G. Brun, Y. Lara, I. Guedea. Design, Development, and Performance Evaluation of a New Photovoltaic-Thermal (PVT) Air Collector: From Lab Testing to Field Measurements. Processes 2023, 11, 588. https://doi.org/10.3390/pr11020588
  • RESEARCH ARTICLE: V. Caballero, A. Briones, A. Coca-Ortegón, A. Pérez, B. Barrios. Analysis and simulation of an Urban-Industrial Sustainable Energy Community: A use case in San Juan de Mozarrifar using photovoltaic energy. Energy Reports, 9 (2023), 0–16. https://doi.org/10.1016/j.egyr.2022.12.059.


  • RESEARCH ARTICLE: R.Simón-Allué, I. Guedea, A. Coca-Ortegón, R. Villén, G.Brun. Performance evaluation of PVT panel with phase change material: Experimental study in lab testing and field measurement. Solar Enerrgy 241 (2022) doi.org/10.1016/j.solener.2022.05.035
  • EUROSUN 2022. R. SImón-Allué, A. Coca-Ortegón, Y. Lara, I. Guedea: Energy Performance of Four Prototypes of PVT Collectors. A Comparative Study. Kassel (Alemania). Septiembre, 2022. Presentación oral y artículo.


  • RESEARCH ARTICLE: A. Coca-Ortegón, M. Herrando, R. Simón Aullé, I. Guedea, N. Fueyo. Experimental Study of a Heating and Cooling Pilot Installation Driven by a Hybrid PV-Thermal Solar Field. Solar World Conference 2021 (SWC), 2021. doi:10.18086/swc.2021.27.01.
  • RESEARCH ARTICLE: Y. Chaibi, T. El Rhafiki, R. Simón-Allué, I. Guedea, S. Cardamas Luaces, O. Charro Gajate, T. Kousksou, Y. Zeraouli. Air-based hybrid photovoltaic/thermal systems: A review. Journal of Cleaner Production 295 (2021).doi.org/10.1016/j.jclepro.2021.12621
  • RESEARCH ARTICLE: G. Zisopulos, A. Nesiadis, K. Atsonios, N. Nikolopoulos, D.Stitou, A. Coca-Ortegón.Conceptual design and dynamic simulation of an integrated solar driven thermal system with thermochemical energy storage for heating and cooling. Journal of Energy Storage 41 (2021). doi.org/10.1016/j.est.2021.102870
  • RESEARCH ARTICLE: Y. Chaibi, T. El Rhafiki, R. Simón-Allué, I. Guedea, S. Cardamas Luaces, O. Charro Gajate, T. Kousksou, Y. Zeraouli. Air-based hybrid photovoltaic/thermal systems: A review. Journal of Cleaner Production 295 (2021) doi.org/10.1016/j.jclepro.2021.126211


  • EUROSUN 2020. R. Simón-Allué, A. Coca-Ortegón, R. Villén, I. Guedea: Performance Evaluation of a Hybrid PVT Solar Installation with Phase Change Material. Online, September, 2020. Oral presentation and article.
  • EUROSUN 2020. M. Herrando, A. Coca-Ortegón, I. Guedea, N. Fueyo: Solar Assisted Heat Pump Systems Based on Hybrid PVT Collectors for the Provision of Hot Water, Cooling and Electricity in Buildings. Online, September, 2020. Oral presentation and article.
  • S2TECH: Sustainable And Smart Technologies Virtual Fair And Congress. PhD. I. Guedea. Electricidad y calor en manos de las personas. Presentation in Energy transition Block. November 2020.


  • RESEARCH ARTICLE: R. Simón-Allué, I. Guedea, R. Villén, G. Brun. Experimental study of Phase Change Material influence on different models of Photovoltaic-Thermal collectors. Solar Energy 190 (2019) 1–9. DOI:10.1016/j.solener.2019.08.005
  • GALERÍA INNOVACIÓN GENERA: M. Cámara, C. Montañés, L. Pérez, A. Gómez, I. Guedea, R. Simón: Development of a digital tool for optimizing the production of hybrid solar panels.. Madrid, Febrero, 2019. Poster presentation.


  • CONTART 2018 (Convención de la edificación). I. Guedea, R. Simón, G. Brun.Paneles solares híbridos: electricidad y calor en un solo panel. Zaragoza, Junio, 2018. Oral presentation y article.
  • IV Congreso de Edificios Inteligentes. R. Simón, O. Puyal e I. Guedea. Smart control of your solar energy: IoT applied to hybrid solar panels. Madrid, June, 2018. Oral presentation and article.
  • GALERÍA INNOVACIÓN GENERA: Guedea, R. Simón, O. Puyal: Smart control of your solar energy: IoT applied to hybrid solar panels. Madrid, June, 2018. Poster presentation.
  • EUROSUN 2018. R. Simón-Allué, I. Guedea, R. Villén, G. Brun: Experimental Investigation of PV/T Collectors with Phase Change Material. Rapperswil (Suiza), September, 2018. Poster presentation and article.
  • IV CONGRESO EDIFICIOS ENERGÍA CASI NULA. R. Simón-Allué, R. Villén, G. Brun, I. Guedea. LOWUP PROJECT: Implementation of four technologies in a pilot plant – Detail of heat recovery kit in PV solar panels with MCF Madrid, November, 2018. Oral presentation and article.