This report assesses how production and emission volumes, energy and CO2 efficiency and competitiveness of companies in the Energy Intensive Industries have evolved prior and during the European Union Emissions Trading System (EU ETS). Furthermore the report assesses how the EU ETS and other policy instruments may have influenced investment and operational choices at the company level. In doing so, this work combines detailed analysis and comparison of available data with comprehensive interviews of industry executives. Building on the experience gathered to date, the project then explored what is needed to unlock the mitigation potentials identified in the low-carbon roadmaps for the sector – with respect to potential reforms of the EU ETS as much as with respect to complementary policy instruments.