Wood biomass is one of the main sources of biofuel for bioenergy production worldwide. Generally, the exclusive use of comminuted biomass in automated boilers is preferred because these woodchips consist of homogeneous particles with a specified size. Wood biomass is harvested mainly in autumn and winter, whereas the demand for biomass-fired power stations is continuous throughout the year. Nevertheless, large amounts of woodchips are also produced in the spring and summer from residual materials obtained from the utilisation of conventional poplar plantations. This study focused on uncovered small and medium woodchip piles. In particular, the influence of form, density, and the size of piles on the biofuel quality during woodchip storage was analysed. The woodchip moisture contents and dry matter losses were considered when evaluating the storage dynamics. The results suggest that a storage system can be selected to service only the needs of thermal stations because any difference between the form (trapezoidal and cone), volume (35 and 70 m(3)), and density of the piles was observed on woodchip quality analysis. In fact, a mean moisture content of 18% and average dry matter losses of 10% were recorded at the end of storage period for all treatments. Notably, the climate conditions and storage periods affected the results of this experiment. (C) 2016 Elsevier Ltd. All rights reserved.