COST EFFICIENT DESIGN OF STORAGE PILES FOR WOOD CHIPS FROM SHORT ROTATION COPPICE

High dry matter losses during storage of wood chips from short rotation coppice (SRC) as well as cost-efficient storage technologies are still matters of much concern. On the basis of poplar harvested at different plantations several long term storage test have been realized in the years 2012 to 2013. Commonly, temperatures in storage piles increase in the first months to more than 50 degrees C due to microbiological and chemical processes. The temperature increase accelerates natural drying but at the same time it is connected to high dry matter respectively energy losses of up to 25 %. Storage losses are influenced by chip size, water content, storage size and design including aeration and covering. Three different storage designs have been investigated for two chips sizes in detail: uncovered piles (100 m(3)), fleece covered piles (100 and 500 m(3)) and silage-film covered piles (100 m(3)). The development of moisture contents, temperatures, moulds, gas concentrations and dry matter losses during storage have been analyzed to identify the best solutions for practice scale storage of wood chips.