Research performed by the "Modelling of energy and environmental impact" group is a contribution to international science as a case study of the process of industrial and energy transition in Slovenia. A study of the energy intensity in the Slovenian industry was published. Researchers participate in several international networks for exchange of knowledge and research results: OPET (European network for promotion of energy efficient technologies), ENER (network for energy-economics research), Reform Group (informal multi-project group of researchers in the area of energy systems and policy, annual meetings) and in European targeted programmes SALE and ALTENER. A basic modelling tool (MESAP-Planet) is based on a programming system developed by University of Stuttgart. Realisation of the energy-environmental model REES for Slovenia is a successful realisation of an internationally recognised model, with original additional modules. Within the BIOMASS (BIOspheric Modelling and ASSessment) programme, dozes for radioactivity inflow into the biosphere according to different scenarios were calculated.