School of Mechanical Engineering

National Technical University of Athens

Associate Professor

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

Tel.  (+30) 210 772-2810. 
Fax  (+30) 210 772-3663. 
email: This email address is being protected from spambots. You need JavaScript enabled to view it. 
Personal Homepage:


  •   Diploma in Mechanical Engineering, National Technical University of Athens, Greece, 2001. 
  •   Ph.D., Lehrstuhl für Energiesysteme, Technische Universiät München, Germany, 2005.

Professional Experience

  •   Research Assistant Lehrstuhl Thermische Kraftanlagen/ Lehrstuhl Energiesysteme Technische Universiät München, 2001-2005. 
  •   Alstom Power, Engineer - Researcher at the combustion department, Circulating Fluidized Bed Design 2005-2006. 
  •   External Research Assistant, Laboratory of Steam Boilers and Thermal Plants, NTUA, Greece 2006-2010. 
  •   External Assistant, National Energy Strategy Chamber, Greece 2007-2008.
  •   Assistant Professor, NTUA, Greece 17.01.2011.
  •   Associate Professor, NTUA, Greece 30.06.2015.

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.


  •   3 years fellow of the State Scholarships Foundation during his studies. 
  •   Award of distinction in Mathematics for the academic years 1997-98. 
  •   Award of the Greek Chamber of Engineers for outstanding performance in his studies during the years 1999-2000. 
  •   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 2001. 
  •   Scholarship of the Alexander Onassis Foundation for PhD studies in a foreign country (Technische Universitat Mόnchen) in the topic of energy production from biomass. 
  •   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. 
  •   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. 

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
Alternate member of the Research Committee of NTUA.
Member of the Inter-departmental Committee of the Postgraduate Programme: Energy Generation and Management.
Academic Responsible of the school of Mechanical Engineering for ERASMUS+.
Alternate member of the school of Mechanical Engineering at the Laboratory committee of NTUA.
Alternate member of the school of Mechanical Engineering at the Energy committee of NTUA.

Teaches at NTUA
Undergraduate: Thermal Energy Conversion in Power Plants I, Thermal Energy Conversion in Power Plants II, Pollution Abatement Technology at Thermal Plants, Environment and Development (Interdepartmental course).
Postgraduate: Thermal Power Plants for Electricity Generation ΙΙ, Co-generation, Fuels and combustion, Pollution Abatement Technology, Thermal Machines, Postgraduate Programme: Energy Generation and Management.