He was born on the 8th of June 1965 in Zabrze, Upper Silesia. After graduation from high school (Śląskie Techniczne Zakłady Naukowe), and passing entry examinations to foreign studies of Warsaw University of Technology, he was a visiting student of the then Ministry of Science and Higher Education of uniform MA studies of Department of Vehicle Engineering of former University of Transport and Communication (Hochschule für Verkehrswesen "F. List" Dresden) in Dresden in 1985 – 1990. In 1986 – 1990 he was a supporting assistant at the Department of Vehicle Air-conditioning and Technical Thermodynamics and under the supervision of Prof Alfred Henatsch he executed research projects within technical thermodynamics, cooling and innovative methods of vehicle air-conditioning.
After graduation from MA studies he started working in the Department of Thermal Engineering of the then University of Technology in Szczecin. Soon he came back to Dresden and in 1990 – 1996, as a visiting doctoral student of then Ministry of Education and German Academic Exchange Service (DAAD - Deutscher Akademischer Austauschdienst) and he defended his doctoral thesis “An Assessment of Air Cooler Powered with Excess Fumes from A Compression-ignition Engine” (“Ein Beitrag zur Bewertung einer abgasangetriebenen Kaltluft-Kältemaschine”) in 1996 at the Department of Mechanics of the University of Technology in Dresden.
In June 2003 he defended at the same University his postdoctoral thesis “A Complete Energy and Ecology Assessment of Energy Technologies with Application of Critical Value of the Process” („Modell einer ganzheitlichen, energie- und umwelttechnischen Bewertung von Energietechnologien unter Verwendung des Begriffs des kritischen Prozesswertes”).
After his come back to Poland he continued his career in the Department of Thermal Engineering of the Szczecin University of Technology, and under supervision of Prof Władysław Nowak and Prof Roman Sobański, and in cooperation with Prof Achim Dittmann, Prof Jarosław Mikielewicz and Prof Joachim Zschernig, he executed many research projects, mainly in terms of technical thermodynamics and evaluation of energetic and environmental capacity of energy technologies. Since 2009 he has been a Head of the Department of Vehicle Operation and the Head of the Section of Energy and Environment Management at the Faculty of Mechanical Engineering and Mechatronics of The West Pomeranian University of Technology in Szczecin.
In 2017 he was awarded the academic degree of professor of technical sciences.
He is an author and contributor of over 130 science publications (mainly in German and English) and his scientific and application interests are connected with energy management; environment management (including carbon management), analysis of lifecycle of energy technologies, theories and operation of combustion engines and problems of sustainable development in the area of energy technologies and mains of transport.
In 2003 – 2006 Prof J. Eliasz was a manager of the research project KBN no. 4T10B 006 25
“The Complete Energy and Ecology Comparative Analysis of Power Station and Wind Energy Station” as well as a coordinator and main executer of the following international projects:
He is a member of the Section of Thermodynamics of the Committee of Thermodynamics and Combustion of the Polish Academy of Sciences (PAN), Polish Scientific Society of Combustion Engines, Section of Energy and Environmental Engineering of The Association of German Engineers (Verein Deutscher Ingenieure), Polish Geothermal Society, and Polish Society of Economic, Legal, and Court Translators.
He is also a lead auditor in terms of Quality Management Systems (since 1998), Environmental Management Systems (since 2004) and Energy Management Systems (since 2011) of the German Certification Institute TÜV SÜD Management Service GmbH in Munich.