Researcher’s night 2019 in Athens

HYBUILD project was presented during the NTUA (National Technical University of Athens) participation in the annually organized pan-European science and research fair “Researchers’ Night 2019”.

During this evening, several scientific research projects were presented to the wider public. The event was attended by members of the academic community from all over the world, while also including school visits.

NTUA booth at the Athens Researcher Night 2019

The event was advertised in the media, attracting a large number of citizens, mainly families with young children, eager to become familiar with the latest achievements in European technology and research.

Learn more about the event at

HYBUILD at the European Researchers’ Night 2019

European Researchers’ Night 2019

European Researchers’ Nights are public events dedicated to bringing researchers closer to the public. They showcase the diversity of research and highlight the impact of research on our daily lives. The aim is also to motivate young people to embark on research careers. The events promote how researchers contribute to our society by displaying their work in an interactive and engaging forum.

Once again this year, HYBUILD was present at the 2019 Researchers’ Night at the University of Lleida which welcomed more than 400 visitors.

A roll-up describing the HYBUILD project was placed at the Europe’s Corner of the event dedicated to the EU projects in which UDL is involved.

European corner at UDL Researcher Night 2019

Participants had the opportunity to get in touch with European research and know more about the new technologies and the current challenges that the actual research is dealing with in different areas. HYBUILD approach to tackle these challenges was explained to those participants who showed interest on the topic.  

Luisa F. Cabeza & Gabriel Zsembinszki at UDL Researcher’s night 2019

Further info at (Spanish) :

HYBUILD at Innovative City in Nice

Regis Decorme from R2M Solution attended and disseminated HYBUILD at Innovative City 2019 | Innovation for Better life and Smart Business | in Nice, France, 15 October 2019.

This new edition of Innovative City had a specific track focused on Smart Grids, which highlighted local demonstration projects such as FLEXGRID, as well as other local initiatives being led by the Smart Grids cluster of the French Riviera Chamber of Commerce.

HYBUILD energy storage solutions can play a significant role in terms of flexibility for the next-generation energy networks.

Read further about Innovative City at

Integration of a compact two fluid PCM heat exchanger into the hot superheated section of an air source heat pump cycle for optimized DHW generation

A new HYBUILD conference paper was presented at the 25th IIR International Congress of Refrigeration, Montreal, Canada, August 24−30, 2019.

This contribution presents a concept for the direct integration of a refrigerant/water Heat Exchanger (HEX) with a Phase Change Material (PCM) in the hot superheated section of an R32 – air source compression Heat Pump (HP) cycle, for optimized Domestic Hot Water (DHW) generation in multi- family houses. The concept takes advantage of the PCMs high thermal storage capacity integrated into a high performance compact enhanced plate-and-fin aluminium HEX. On the refrigerant side, it works as a de-superheater for DHW generation during heating and cooling operation whereas the process water is connected to decentralized DHW storages located in single apartments of a low energy building. We present results from simulations at a system level for typical operating conditions and corresponding seasonal and annual performances. Compared to conventional systems, the results indicate savings up to 11% of electric energy over the year for DHW generation in average climate.

Read the full paper on the Scientific publications page.

Copyright © IIF/IIR. This paper is published with the authorization of the International Institute of Refrigeration (IIR):

Phenomenological modelling of phase transitions with hysteresis in solid/liquid PCM

A new HYBUILD paper has been released in the Journal of Building Performance Simulation.

Technical-grade and mixed solid/liquid phase change materials (PCM) typically melt and solidify over a temperature range, sometimes exhibiting thermal hysteresis. Three phenomenological phase transition models are presented which are directly parametrized using data from complete melting and solidification experiments. They predict hysteresis phenomena and are used to calculate effective PCM properties. Two models have already been implemented in commercial building simulation and/or multiphysics software, but not the third novel model. Applications are presented for two commercial PCM: a paraffin, and a salt water mixture with additives. Numerical implementation aspects are discussed, and significant differences in the predicted absorbed and released heat are highlighted when simulating consecutive incomplete phase transitions. The models are linked with energy balance equations to predict recorded PCM temper- atures of a thermal energy storage. The cross-validation with data from 26 partial load conditions clearly indicate a superior predictive performance of the novel hysteresis model.

Link to the full paper

FRESNEX collectors installed at the HYBUILD Spanish demo site

At the HYBUILD Spanish demo site located in Almatret, solar collectors provided by FRESNEX have just been successfully installed. Local stakeholders, in particular from the town of Almatret and from University of Lleida, have been trained on the overall system functioning and on its control / tracking system.

Fresnex solar collectors in Almatret, HYBUILD Spanish demo site 

Fresnex solar collectors in Almatret, HYBUILD Spanish demo site

During the upcoming months, this system will be incrementally integrated with the other technological components, to form the overall HYBUILD hybrid storage solution.

Further information about Almatret & the Almia initiative : 

Introducing HYBUILD’s heat exchanger manufacturer: AKG group

HYBUILD is a group of 21 partners from 9 countries. Every month, a new HYBUILD partner is introduced in our Blog section. Today: AKG – the cooling experts, manufacturer of the heat exchangers for the project.

AKG in a nutshell

The AKG group of companies – A strong global group of companies

As a leading supplier of customer-oriented solutions, AKG has acquired an internationally acclaimed reputation for producing reliable, high-quality radiators and heat exchangers.

The AKG Verwaltungsgesellschaft (holding company) in Hofgeismar, Germany directs the operation of the AKG Group, whose 2,800 employees produce over 2.5 million heat exchangers in various designs each year. To achieve this, 12 business units in Germany, France, Latvia, Turkey, India, USA, Brazil and China as well as 10 oversea sales companies are in operation twenty-four hours per day.

AKG develops and manufactures high-performance heat exchangers and complete cooling modules for application in construction equipment, compressed air equipment, industrial coolers, agricultural and forestry equipment, railroad vehicles, aviation, household appliances and special applications.

For 100 years AKG Heat-Exchangers are standing for innovative solutions as well as highest engineering and manufacturing competence.

AKG’s role in HYBUILD

AKG builds the aluminium heat exchangers for the HYBUILD-project.

AKG offers a wide range of heat exchanger designs, which includes brazed bar-plate coolers, stacked-shell coolers as well as various types of tube-and-fin heat exchangers.

For compressed air application AKG is not only providing the coolers for oil or compressed air but also evaporators for refrigeration dryers. For one customer AKG already manufactures evaporators with integrated thermal storage (PCM) to improve the performance of the refrigeration system. The similar design principle is used to store thermal energy for the hot and cold storage for the HYBUILD-project. Integrating the PCM directly in the heat exchangers allows a compact and fast reacting storage solution.

Beyond customized solutions for various industries AKG also manufactures special heat exchangers for research institutes to help promote new technologies.

Following are photos of some of the special heat exchangers that AKG has manufactured for use in the HYBUILD-project.

Picture of a lab-scale RPW-HEX (Refrigerant-PCM-Water-Heat Exchanger)

Picture of a full-scale RPW-HEX for installation in one of the demo-sites

Picture of a heat exchanger to act as adsorber after zeolite treatment

Get in touch: key staff from AKG involved HYBUILD

Dr. Katerina Hatesuer is project manager in the Research and Development department of the AKG group. She obtained her Bc. degree in mechanical engineering at the Czech Technical University in Prague (CZ) and her M.Sc. and later the Dr.-Ing. degree at the University in Kassel (D) first in engineering of Regenerative Energy and Energy efficiency (M.Sc.) and followed in Thermal Energy Management (Dr.). She has been joining AKG since August 2018 and is responsible for the thermal dimensioning of the heat exchangers.

Birgo Nitsch is project manager in the Research and Development department of the AKG group. He obtained diploma in Mechanical Engineering at the Technical University of Dresden. Since 1999 he has been working for AKG in the development of heat exchangers, with a focus on brazed and bonded heat exchangers for various applications (e.g. fuel cells, tumble dryers, heat pumps). He is also responsible for prototype building and the vacuum brazing shop.

Dr. Andreas Strehlow is director of Research and Development of the AKG group. He obtained a degree in chemical engineering and specialized in fluid dynamics at the Technical University of Dortmund. He works in the development of heat exchangers since 1994, where the focus was on large regenerative heat exchangers for power stations. He joined AKG in 2003 and is responsible for developing, building and testing of high performance heat exchangers for the AKG group.

HYBUILD at the 5th International Seminar on ORC Power Systems

HYBUILD was exhibited at the 5th International Seminar on
ORC Power Systems.

The event was organised by the Knowledge Center on Organic Rankine Cycle technology – KCORC in cooperation with the National Technical University of Athens (NTUA).

The conference was focused on promoting the development of science and technology in power and propulsion applications based on thermodynamic cycles employing organic compound as working fluids.

Interest in these technologies is growing because ORC systems can be used for the conversion of renewable energy sources such as solar radiation, geothermal reservoirs, biomass fuel and waste heat from various processes and engines.

Learn more at the conference website.

Phase change material selection for two innovative compact energy storage systems in residential buildings

New conference paper released by University of Lleida at XI Congreso Nacional y II Internacional de Ingeniería Termodinámica

Within the framework of HYBUILD, an EU Horizon 2020-funded project, two innovative compact hybrid electrical/thermal storage systems for stand-alone and district connected residential buildings will be developed and tested in three demos located in Spain, France, and Cyprus. One of the innovative systems is aimed to be placed in buildings located in Mediterranean climate regions, where cooling loads are dominant, while the other system is intended for Continental climate regions, where the heating demand is dominant. Each system will include, among others components such as a sorption storage system and domestic hot water tanks, a latent thermal energy storage (LTES) system that will be connected to a heat pump through an innovative heat exchanger made of aluminium and filled with phase change material (PCM). In both cases, the heat pump works with electricity provided by a photovoltaic system that is, at the same time, connected to an electrical storage battery. The aim of using the LTES system is to enhance the use of solar energy, which will be translated into a reduction of the building energy consumption and related costs. This study focuses on the selection of the most suitable PCM to be used in each system. On the one hand, the LTES system of the Mediterranean system will be used to store cold to reduce the cooling demand. Taking into account that, according to the design parameters, the heat pump will require a refrigerant evaporation temperature around 2 oC, and the building cooling system will require water supply in the range from 7 oC to 12 oC, the PCM melting temperature range should be within 0 oC and 7 oC. On the other hand, the LTES system of the Continental system will be used to store heat to reduce the domestic hot water (DHW) demand. The LTES will be located at the compressor outlet and will be charged by the hot refrigerant that exits the compressor at temperatures as high as 120 oC. During the discharge process, the heat stored in the LTES will be supplied to the DHW at a temperature in the range between 50 oC to 55 oC. As a consequence, the range for the PCM melting temperature investigated in this case should be between 62 oC and 68 oC. Besides the melting temperature, other selection criteria considered include the PCM melting enthalpy and melting range, maximum allowed working temperature, density, thermal conductivity, availability, cost, and compatibility with aluminium. To decide the ideal PCM candidate for each system, a decision matrix was defined and used, by applying a weighted score to the selection criteria items according to their importance. The preliminary results indicate that for the Mediterranean system the best candidate is the commercial savE OM3 PCM, while for the Continental system, another commercial product PureTemp 63 is the most adequate option.

Read the full paper

Introducing FOSS | the Research Centre for Sustainable Energy of the University of Cyprus

HYBUILD is a group of 21 partners from 9 countries. Every month, a new HYBUILD partner is introduced in our Blog section. This month, the Research Centre for Sustainable Energy of the University of Cyprus.

The Research Centre for Sustainable Energy (FOSS) was created in order to play a key role in research and technological development activities in the field of sustainable energy within Cyprus and at international level with the aim of contributing to the achievement of the relevant energy and environment objectives set out by Europe. In particular, the FOSS strives to become a centre of excellence in energy that will act as a structure where world-standard R&D work can be performed, in terms of measurable scientific value (including training) and/or technological innovation. In FOSS significant research expertise from the University of Cyprus as well as from industry has been assembled that spans a wide range of fields: Electrical, Mechanical, Civil, Environmental, Chemical engineering, ICT, Physics, Chemistry, Economics, Finance, as well as Architecture. The FOSS team aims, with the development of the necessary synergies, to create the impetus for the advancement of the field of energy. Members of the Centre represent Cyprus in European Energy Committees such as the Energy Committee for the Horizon 2020, the SET Plan, the European Technology and Innovation Platform SNET and PV and the European Standards Committees on PV. Currently FOSS is a full member of DERlab, EUREC and EERA JP for SG. The researchers involved in the working team have extensive experience in grant proposal applications and have acquired funding for a range of research topics through the EU, the National Research Funding Agency in Cyprus as well as industry.

FOSS is heavily involved in all spheres of sustainable energy spreading from sources of energy, smoothly merging RES in the integrated solutions of the grid, development of enabling technologies such as storage and ICT that will facilitate the seamless merging of sustainable technologies in the energy system of tomorrow, the complete transformation of energy use by the effective introduction of sustainable alternatives in meeting the needs for mobility, heating and cooling and exploring ways of achieving even higher levels of efficiency in all areas of the economy.


In the framework of the HYBUILD project, FOSS Research Centre for Sustainable Energy, is responsible for system analysis and design, particularly for the Cyprus demo site, simulation activities and system integration. In addition, FOSS helps on the coordination of the Cyprus demo site activities in collaboration with the Municipality of Aglantzia and other partners. Furthermore, as a university institution, participates in the dissemination of the project and its results in international scientific journals and conferences.

HYBUILD Cyprus demo site (1/2)

HYBUILD Cyprus demo site (2/2)

Get in touch !

FOSS staff involved in HYBUILD are George E Georghiou, Venizelos Efthymiou, Aimilios Michael, Chryso Heracleous, Chrysanthos Charalambous.

George E Georghiou. Dr George E. Georghiou is the Director of FOSS Research Centre for Sustainable Energy and the leader of PV Technology, Department of Electrical and Computer Engineering, University of Cyprus. Prior to this, he was a University Lecturer and the undergraduate course leader in Electrical Engineering at the University of Southampton, and a Research Advisor for the Electricity Utilization, University of Cambridge. Having graduated from the University of Cambridge with a BA, MEng, MA (1996) all with distinction and a PhD (1999), Dr Georghiou continued his work at the University of Cambridge in the capacity of a Research Fellow (1999-2002). Dr Georghiou is currently a member of the Cyprus Energy Policy Council, the CENELEC and IEC committees on PV and is acting as an expert evaluator and reviewer for Horizon 2020 energy proposals as well as being a member of CIGRE and the European Solar Energy Industrial Initiative. He also represents Cyprus on the SET plan steering committee, the European Mirror Group on Photovoltaics and sits on the board of the Cyprus Energy Agency. Dr Georghiou has published over 300 papers in international journals and conference proceedings and his team has obtained research funding in excess of 10 million Euros from bodies such as the European Union, Industry (such as Honeywell, Q Cells, Tel-Solar, TSMC etc), Royal Society, Cambridge-MIT Institute, University of Cambridge, Research Promotion Foundation, Electricity Authority of Cyprus, Cyprus Energy Regulatory Authority etc. Amongst his scholarly achievements, are five outstanding paper awards for the most significant technical scientific contributions and an innovation prize.

Venizelos Efthymiou. Dr Venizelos Efthymiou from Cyprus is a holder of the UMIST university degrees: BSc in Electrical Engineering and Electronics, Master of Science (MSc) in Power Systems and Doctor of Philosophy (PhD). He worked for the Electricity Authority of Cyprus from March 1979 up to November 2013 and he left the Company from the post of Executive Manager Networks and from the post of Manager of the Distribution System Operator of Cyprus. He is a member of the Steering Committee of the European Technology and Innovation Platform of SNET, a member of the Steering Committee of PV Technology and Innovation Platform, a member of the DSO Committee of EURELECTRIC, chairman of the Research Centre FOSS of the University of Cyprus and chairman of CIGRE Cyprus.

Aimilios Michael. Architect Engineer Dipl.Arch.Eng., M.Sc., Ph.D., is an Assistant Professor in the Department of Architecture at the University of Cyprus, Director of Energy & Environmental Design of Buildings Research Laboratory (E&EDB) and member steering committee of the Inter-departmental Master Programme, Energy Technology and Sustainable Design of the Faculty of Engineering of the University of Cyprus. Aimilios Michael currently holds the position of Vice-President of the Council for Planning Derogation Applications, Ministerial Council Appointment. He is also member of the Board Council of the Scientific Technical Chamber of Cyprus, CSTC. Aimilios holds a PhD in Environmental Design and Energy in Architecture from the Department of Architectural Technology, School of Architecture, National Technical University of Athens, NTUA. During his studies, he was awarded numerous academic performance distinctions, including the Academic Excellence NTUA Award 2004, NTUA Silver Medal 2004 (1st rank), Best Design Diploma Thesis NTUA Award 2004 and Nomination for Best Doctoral Dissertation Award NTUA 2011. His research activities take on an interdisciplinary perspective and they focus on the areas of Energy and Environmental Design of Buildings and Advanced Architectural Technology. He participated as principal investigator and/or project coordinator in several funded research programmes. His architectural work -placing emphasis on energy and environmental architecture- has won awards (16) in architectural European and international competitions, including 1st prizes (2), and was presented in several architectural exhibitions in Cyprus and abroad. His research work has been published in books, refereed journals and conference proceedings.

Chryso Heracleous. Chryso Heracleous is a research fellow, seasonal lecturer and PhD candidate in the Department of Architecture of the University of Cyprus. She holds a bachelor’s degree in Architecture Engineering from the Technical School of the University of Patras, a Master’s in Environmental Design from the University of Bath (UK), and she is Certified Passivhaus Designer from the Passivhaus Institut, Germany. Her research interest focuses on the fields of Architectural Building Technology, Environmental Design and Energy Performance of Buildings with main purpose energy saving and improvement of human comfort, health and productivity. Since 2013, she participated as researcher in several research programmes funded by the European Commission, Directorate General for Research & Innovation, Research Promotion Foundation IPE-RPF and published her scientific work in some international conferences and scientific journals.

Chrysanthos Charalambous. Chrysanthos Charalambous was born in Cyprus on July 11, 1989. He received the bachelor’s degree and the MSc degree in Electrical and Computer Engineering from the Democritus University of Thrace, Xanthi, Greece, in 2014 and 2016, respectively. Now he is student of PhD in Electrical Engineering at University of Cyprus since January 2018, and special scientist at FOSS Research Center for Sustainable Energy. His research interests include power systems, renewable energy, smart grids, DC and hybrid DC-AC power systems, and distributed energy resources. Since 2017, he participated as a researcher in several research programmes funded by the European Commission, and Research Promotion Foundation IPE-RPF. In addition he has successfully attended the KNX course for smart home and building automation solutions.