Biomass harvesting from buffer strips in Italy: three options compared

There is an urgent need for new, mechanized systems that may restitute some profitability to buffer strip harvesting and motivate regular maintenance. An opportunity for innovation is offered by the growing success of chip-fed boilers, since the production of chips is simpler than that of logs and has a higher potential for cost reduction. Within this context, a study was conducted in Italy with the goals of: (a) designing three alternative chip harvesting methods for buffer strips, (b) field-testing the performance of each alternative, and (c) developing a model for estimating the cost of these methods under varying operational and economic conditions. The three harvesting methods reflected different mechanization levels, with escalating investment requirements. Overall, the study demonstrated that frequent maintenance of young, single row buffer strips generates profits only when thoroughly mechanized. Using a dedicated feller-buncher, a front-end loader for extraction and an industrial truck-mounted chipper brought the delivered cost below the 14 EURO/m(3) supercript stop loose chips (approximately 4 EURO/GJ) presently paid by the district heating stations. However, the intermediate- mechanization system showed the highest potential for improvements. The study generated a spreadsheet-based model for predicting the effects of varying work conditions and cost hypotheses.