1987, May 25-29, Rome, Italy: 4th International Symposium on 2nd Law Analysis of Thermal Systems:
Organizing Committee: R. Melli, E. Sciubba
Executive Committee: R.A. Gaggioli, M.J. Moran, E.Sciubba

1989, June 5-8, Beijing, China: Thermodynamic Analysis and Improvement of Energy Systems (TAIES ´89), International Symposium. 
Organizing Committee: C.H. Wu, R.A. Gaggioli
Executive Committee: Ruixian Cai, M.J. Moran


1990, May 28 – June 1, Florence, Italy: Florence World Energy Research Symposium (FLOWERS ´90).
S.S. Stecco, M.J. Moran.


1991, June 3-6, Athens, Greece: Analysis of Thermal and Energy Systems (ATHENS ´91), International Conference. 
Executive Committee: D.A. Kouremenos, R.A. Gaggioli, M.J. Moran
Organizing Committee: G. Tsatsaronis, C.D. Rakopoulos


1992, June 15-18, Zaragoza, Spain: International Symposium on Efficiency, Costs, Optimization and Simulation of Energy Systems (ECOS ´92)
A. Valero, G. Tsatsaronis.


1993, July 5-9, Cracow, Poland: Energy Systems and Ecology (ENSEC ´93), International Conference.
J. Szargut, G. Tsatsaronis, Z. Kolenda, A. Ziebik.


1994, July 6-8 Florence, Italy: Florence World Energy Research Symposium (FLOWERS ´94)
E. Carnevale, G. Manfrida, F. Martelli.


1995, July 11-14, Istanbul, Turkey: International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS ´95)
Y.A. Gögüs, A. Öztürk, G. Tsatsaronis


1996, June 25-27, Stockholm, Sweden: International Symposium on Efficiency, Costs, Optimization, Simulation and Environmental Aspects of Energy Systems (ECOS ´96)
G. Svedberg, G. Manfrida, M.J.Moran, G. Tsatsaronis


1997, June 10-13, Beijing, China: Thermodynamic Analysis and Improvement of Energy Systems (TAIES ´97), International Conference.
Scientific Committee: Ruixian Cai, M.J.Moran, G. Tsatsaronis
Organizing Committee: Jingyi Chen, E. Sciubba


1998, July 8-10, Nancy, France: Efficiency, Costs, Optimization, Simulation and Environmental Aspects of Energy Systems and Processes (ECOS ´98)
Honorary Chairmen: E.P. Gyftopoulos, P. Le Goff
M. Feidt, A. Bejan, M.J. Moran, G. Tsatsaronis


1999, June 8-10, Tokyo, Japan: Efficiency, Costs, Optimization, Simulation and Environmental Aspects of Energy Systems (ECOS ´99)
M. Ishida, G. Tsatsaronis, M.J. Moran, H. Kataoka


2000, July 5-7, Enschede, The Netherlands: International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Aspects of Energy and Process Systems (ECOS 2000)
Honorary Chairman: J. Szargut
G.G. Hirs, G. Tsatsaronis, M.J. Moran


2001, July 4-6, Istanbul, Turkey: Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS ´01)
Honorary Chairman: E.P. Gyftopoulos
A. Öztürk, A. Bejan, M. Feidt, Y.A. Gögüş


2002, July 3-5, Berlin, Germany: 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2002)
Honorary Chairman: K.F. Knoche
G. Tsatsaronis, M.J. Moran


2003, June 30 – July 2, Copenhagen, Denmark: The 16th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2003)
Organizing Committee: B. Qvale (Chairman)
Scientific Committee: N. Houbak, M.J. Moran


2004, July 7-9, Guanajuato, Mexico: 17th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy and Process Systems (ECOS 2004)
Organizing Committee: R. Rivero (Chairman)
G. Tsatsaronis, M.J. Moran


2005, June 20-22, Trondheim, Norway: The 18th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2005)
Organizing Committee: S. Kjelstrup (Chairman)
Scientific Council: J.E. Hustad (Chairman)


2006, July 12-14, Aghia Pelagia, Crete, Greece:The 19th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2006)
Honorary Chairmen: E.P. Gyftopoulos, G. Hatsopoulos
C.A. Frangopoulos, C. Rakopoulos, G. Tsatsaronis


2007, June 25-28, Padova, Italy: The 20th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2007)
A. Mirandola, Ö. Arnas

2008, June 24-27, Kraków, Poland: The 21st International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2008)
Zygmunt Kolenda, Andrzej Ziębik

2009, August 31 - 3 September, Foz do Iguaçu - Paraná, Brasil : The 22th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2009)
Silvia Azucena Nebra, Silvio de Oliveira Júnior, Edson Bazzo, Arnaldo da Silva Walter


2010, June 14-17, Lausanne (EPFL), Switzerland: The 23th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2010)
Daniel Favrat, François Maréchal

History