This thesis investigates relationships between the European Union Emission Trading Scheme (EU ETS) and energy markets. A special focus is given to fuel switching, the main shortterm abatement measure within the EU ETS. This consists in substituting Combined Cycle Gas Turbines (CCGTs) for hard-coal plants in off-peak power generation. Thereby coal plants run for shorter periods, which allows power producers to reduce their CO2 emissions. In Chapter 1, we outline different approaches explaining relationships between carbon and energy markets. We also review the literature relating to these issues. Next, we further describe the fuel switching process and, in particular, we analyze the influence of energy and environmental efficiency of thermal power plants (coal and gas) on fuel switching. In Chapter 2, we provide a theoretical analysis that shows how differences in the efficiency of CCGTs can rule interactions between gas and carbon prices. The main result shows that the allowance price becomes more sensitive to the gas price when the level of CO2 emissions increases. In Chapter 3, we examine interactions between carbon, coal, gas and electricity prices in an empirical study. Among the main results, we find that there is a significant link between carbon and gas prices in the long-run equilibrium.In Chapter 4, we analyze the cross-market price discovery process between gas and CO2 markets. We identified in previous chapters that there is a robust significant link between gas and CO2 markets. They are linked commodities, and their prices are affected by the same information. In an empirical analysis, we find that the carbon market is the leader in cross-market price discovery process.
