Energy evaluation of forest residues originated from shrub species in Galicia

In this study we present an alternative for the management of the excess of shrub species that nowadays take up around 800 000 ha in Galicia (NW Spain). This alternative is based on the exploitation of the energetic resources contained in the excess of shrubs by their combustion in specially designed plants for production of electric energy. The different species were sorted into three groups: Ulex europaeus L. (furze), Sarothamnus scoparius (L.) Link (broom) and Erica sp. (heaths). Their LHV were calculated through measurements of the corresponding HHV and resulted 7600, 7300 and 7200 kJ kg−1 respectively. Biomass productions (T ha−1) were also calculated resulting 20 T ha−1 (furze), 30 T ha−1 (broom), and 15 T ha−1 (heaths). Analyses of all these values make these species very valuable for their energy exploitation. Samples were collected over one year in different zones to study the effect of the environmental conditions on the calorific values.