School of Mechanical Engineering

National Technical University of Athens


Address: National Technical University of Athens,
Heroon Polytechniou 9, 15780 Zografou, Athens, Greece,
School of Mechanical Engineering, Section of Thermal

Tel.  (+30) 210 772-3683, (+30) 210 772-2810.
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2005 Ph.D., Lehrstuhl für Energiesysteme, Technische Universiät München, Germany
2001 Diploma in Mechanical Engineering, National Technical University of Athens, Greece

Professional Experience

2019 - today Professor, NTUA, Greece
2015 - 2019 Associate Professor, NTUA, Greece
2015 - today Visiting Professor Universität Bayreuth, Germany
2013 - today Visiting Professor TU München, Germany
2011 - 2015 Assistant Professor, NTUA, Greece
2007 - 2008 External Assistant, National Energy Strategy Chamber, Greece
2006 - 2010 External Research Assistant, Laboratory of Steam Boilers and Thermal Plants, NTUA, Greece
2005 - 2006 Alstom Power, Engineer - Researcher at the combustion department, Circulating Fluidized Bed Design
2001 - 2005 Research Assistant Lehrstuhl Thermische Kraftanlagen/ Lehrstuhl Energiesysteme Technische Universiät München

Thermal Plants, steam generators, optimization of energy systems, Cost of electricity production, Thermodynamic analysis and applications of the Organic Rankine Cycle, thermodynamic cycles, waste heat utilization from industrial processes, co- (poly-) generation, decentralized energy production, biomass and waste gasification and combustion, SNG production, Carbon Capture and Storage technologies, Energy Storage, Hydrogen technologies.


2021 "Prof. Gianfranco Angelino" award for the best poster at the ORC 2021 - 6th International Seminar on ORC Power Systems (11-13 October 2021). Poster title: Economic model predictive control on a waste heat recovery micro ORC. Authors: E. Varvagiannis , I. Kalogeropoulos, T. C. Roumpedakis, P. Pallis, S. Karellas, H. Sarimveis
2006 Award S.A. Routsis for the best scientific work from young scientist at the conference ECOS 2006, 19th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems. Paper Title: An innovative biomass gasification process and its coupling with microturbines and fuel cell systems, Authors: S. Karellas, J. Karl, E. Kakaras
2006 Award for the Best Poster Presentation in the Eighth Grove Fuel Cell Symposium, Elsevier, Poster title: Integration of SOFC fuel cells systems in CHP-Systems with indirect gasification, Authors: J. Karl, S. Karellas, D. Hein
2005 Scholarship of the Alexander Onassis Foundation for PhD studies in a foreign country (Technische Universitat München) in the topic of energy production from biomass
2001 Diploma and medal of honour from the National Technical University of Athens, Award "X. Hrysovergi" and Award "Stylianis Samara and Anastasia Synouri" for the best graduated mechanical engineer of the year
1999 - 2000 Award of the Greek Chamber of Engineers for outstanding performance in his studies during the years
1999, 2000, 2001 3 years fellow of the State Scholarships Foundation during his studies
1997 - 1998 Award of distinction in Mathematics for the academic years

Member of:
Member of the Technical Chamber of Greece.
Member of the Verein Deutscher Ingenieure (VDI).
Member of the Hellenic Association for the Cogeneration of Heat and Power (HACHP).
Member of the Innovation Committee of the School of Mechanical Engineering.

Current Duties
Director of the Laboratory of Thermal Processes.
Scientific Responsible and Chair of Research of EULiST.
Representative of NTUA at the General Assembly of the Hellenic Foundation for Research & Innovation.
Member of the Scientific Committee of NTUA.
Member of the Inter-departmental Committee of the Postgraduate Programme: Energy Generation and Management.
Member of the Inter-departmental Committee of the Postgraduate Programme: Environment and Development.
Coordinator of the Publicity and Communication Committee of the School of Mechanical Engineering.

Teaches at NTUA
Heat transfer, Thermal Energy Conversion in Power Plants, Energy Management, Decentralised Thermal Energy Systems, Pollution Abatement Technology at Thermal Plants, Energy Storage Systems, Environment and Development (Interdepartmental course, Coordinator).
Thermal Power Plants and Co-generation, Environmental Technology and Management, Postgraduate Programme: Energy Generation and Management,
Clean Technologies, Energy and Environment, Postgraduate Programme: Environment and Development.