Researches of the "Modelling of energy and environmental impact" group are intended to provide scientific support for development decisions in Slovenia, in particular also for 1) energy strategy with considerations of liberalised energy markets and of the commitments accepted in the Kyoto protocol, 2) development programme in Slovenia for qualified production of electricity (i.e. production from renewable energy sources and by combined heat and power production, CHP), 3) optimisation of CHP production under conditions of a liberalised electricity market, 4) estimating development paths of economic sectors, their environmental significance and consequences for the energy sector and for emissions into the atmosphere (particularly of the greenhouse gases). During the execution of the programme methodological research has been completed and a model of the environmental impact through emission of greenhouse gases for the energy sector and other relevant sectors (agriculture, traffic, forestry, waste management, industry, services and households) was rounded up. In applied researches, projections of energy use, according to selected energy policies, have been developed for the National energy programme decisions and for the Operational programme for reduction of GHG emissions. On the basis of these researches cited policy documents have been prepared in 2003 in the responsible ministry. An applied study is under development (nearing completion) for comparison of measures for the reduction of GHG emissions, to be used for further decisions and activities in the energy sector and for mitigation of their environmental impacts. Similar modelling and planning approaches have been also applied for development of programmes for promotion of energy efficiency and increased use of renewable energy sources; as well as for cogeneration in industry and for municipal development programmes. Within a Leonardo da Vinci international project, different study models were elaborated and a textbook on Environmental Chemistry was issued.