COFIRING VERSUS BIOMASS-ONLY POWER PLANTS: GHG EMISSIONS SAVINGS COMPARISON BETWEEN COAL AND FOREST RESIDUES UTILIZATION BY MEANS OF LCA METHODOLOGY

ABSTRACT: Electricity generation has to take into account new parameters that have been acquiring an increasing importance due to the current environmental and economic situation. In order to meet environmental commitments and reach renewable energy targets, different alternatives can be implemented. One way of producing nearly CO2 free electricity is by means of using biomass as a combustible because this fuel is normally evaluated as CO2 neutral. Forest residues share in the energy market increase would even more interesting than other biofuels contribution increase, especially in Mediterranean areas, since this action, besides helping green electricity production, would contribute to decrease fire risks. Forest residues electricity conversion in Southern areas is under it was expected due to low yields, scattered enough productive forest areas, important slopes, difficult accesses, etc. For forest residues electricity generation purposes two different alternatives could be set up: biomass-only fired power plants or co-firing. One important aspect that has to be analyzed is which of both options the most interesting alternative is when greenhouse (GHG) emissions are considered. The best alternative could achieve more grants or premiums which could boost forest residues. In order to quantify the magnitude of the GHG emissions decrease offered by each system a Life Cycle Assessment (LCA) methodology has been performed including all the processes involved in each alternative in a cradle-to-grave manner