Deriving efficient policy portfolios promoting sustainable energy systems—Case studies applying Invert simulation tool

Within recent years, energy policies have imposed a number of targets at European and national level for rational use of energy (RUE), renewable energy sources (RES) and related CO2 reductions. As a result, a wide variety of policy instruments is currently implemented and hence the question arises: how can these instruments be designed in a way to reach the maximum policy target with the minimum public money spent?The objective of this paper is to derive a methodology for obtaining efficient policy portfolios promoting sustainable energy systems depending on the policy target and show corresponding results from case studies in Austria, Germany and Poland.The investigations were carried out by application of Invert simulation tool, a computer model developed for simulating the impacts of various promotion schemes for renewable and efficient energy systems. With this tool, the CO2 reductions and related public expenses have been calculated for various policy mixes.In the building-related energy sector, it turned out that in all investigated regions support schemes for supply side measures are the most cost-efficient instruments. However, their potential is restricted and for achieving higher levels of CO2 reduction, promotion of demand side measures is indispensable.The paper shows that for a comprehensive comparison of policy portfolios, there are always two dimensions to be considered: efficiency and effectiveness. The more effective, i.e. the higher the implementation rate of a scheme, the more essential becomes the efficiency criteria.