De los consumos finales de energía a los requerimientos de energía primaria y las emisiones de CO2. Aproximación a partir de los balances de energía. Aplicación a Cataluña, 1990-2005

This paper analyzes the evolution of the uses of primary energy and the resulting CO2 emissions in Catalonia during 1990-2005. We present a method that allows – from the energy balances – to «translate» final consumption of energy into primary energy requirements. This technique estimates the quantity of primary energy (and its composition) that pulls a given level of final energy consumption of the different sectors or activities. We compare the results for 2003-2005 with the ones for 1990-1992. The most relevant changes are the reduction in the primary energy required for obtaining a unit of electricity and the change in its average composition by primary energy sources. We decompose the changes in primary energy into three effects: the change in the level of final consumption of the different sectors (“energy final consumption”) and the changes between different types of final energies (“substitution effect”) and the changes in the needs of primary energy for obtaining final energies (“transformation effect”). Finally, the paper translates the primary energy requirements into the corresponding emissions and analyzes their evolution by means of the factoral decomposition abovementioned.