The objective of this project was to provide IPTS with a powerful and transparent model system that accommodates rigorous and comprehensive quantitative assessment of the economic impacts induced by energy, technology and climate policies. The project has built on the existing large-scale, multi-sector, multi-region computable general equilibrium (CGE) model GEM-E3-World that has been successfully used for environmental and energy policy analysis at the EU and world level. GEM-E3-World was adapted to meet the IPTS needed with respect to the comprehensive analysis of climate and energy policy issues paying particular attention to flexible problem-driven spatial, sectoral and temporal resolution. The model system was set up to allow for a flexible dis-aggregation of sectors and regions (including groups of EU candidate countries) as well as the choice of mid-/long-term model horizons.