Energy and economic evaluation of a poplar plantation for woodchips production in Italy

Abstract

In Europe, farmers prefer the very Short Rotation Coppice (vSRC) cultivation model, with a very high plant density (5500–14,000 p ha−1) and a harvesting cycle of 1–4 years; while in Italy, recently, the farmers prefer the Short Rotation Coppice (SRC) method, with a high plant density (1000–2000 p ha−1) and a harvesting cycle of 5–7 years. This is because the most recent poplar hybrids have enhanced productivity and improved the biomass quality (calorific value), as a result of a better wood/bark ratio.In order to evaluate, from the energy and economic point of view, a poplar SRC, in the river Po Valley, an ad hoc study was made and a specific model was developed.On the basis of this cultivation technique, an energy and economic evaluation of a poplar SRC in Northern Italy was realised. In detail, were considered data of poplar growth, in a plantation for the production of 6 year whips, in Western Po Valley, considering a SRC duration of 6 years and a biomass (15 Mg ha−1 dry matter – D.M. per year) harvest at the end of cycle (6 years). In this computing system it was pointed out that the SRC is very interesting from an energy point of view, since the output/input ratio results to be higher than 18. The same is not true for the poplar SRC from an economic point of view. In order to obtain economic SRC sustainability, the biomass price should be at least 115 € Mg−1 D.M. A large biomass diffusion will be possible only with an increase of the biomass market value, or with economic sustain for its production.