Biomass residues for energy production and habitat preservation. Case study in a montado area in Southwestern Europe

Abstract

The use of forest and agricultural residues for energy production presents multiple benefits, but the link between bioenergy and the environment is complex and not all of the energetic options have the same impacts. This work evaluates the net positive effect of valorizing residual biomass in the context of a rural area of Portugal, Estremoz. It focuses on the combined assessment of biomass availability, techno-economic feasibility and environmental aspects of utilizing forest and agricultural residues to produce bioheat. At first, the energy potential of the residual biomass available in the municipality is evaluated using a geographical information system database. The assessment with RETScreen of the techno-economic feasibility of replacing electricity by biomass for heating local public schools follows. The results show that around 27 314 t of residues, corresponding to about 267 680 GJ, are produced each year in Estremoz, more than half in montado areas. The use of this biomass for the replacement of the existing electric heating systems of nine local schools by biomass-based ones offers good project profitability. As far as the environment is concerned, the energetic valorization of the residual biomass in Estremoz has multiple benefits. It contributes to climate change mitigation by saving greenhouse gas emissions and promoting the preservation of the traditional extensive uses of the ecosystems. Moreover, a correct vegetation management decreases the fire risk, potentiates the increase in biodiversity, offers better conditions for native species and allows to maintain the ecosystems.