SAC hails bales as possible way to store willow
By Andy Collings
CHIPPING willow coppice material is not necessarily the best way of storing the material before it is used in energy producing systems, says the SAC.
The college points out that chips stored for any length of time can heat up, ferment and loose valuable energy content.
An alternative storage system is now being evaluated and calls for the cut willow to be baled – a system which would enable the cut coppice to breath and maintain its condition.
Various types of baler have been tried – including big round and square machines. The round baler requires the coppice to be cut to a set length and fed into the chamber in an ordered manner while the square baler, with its powerful plunger appears to be happy being presented with material in most formats – providing it isnt over-sized.
The SAC suggests coppices may have to be cut at two-year intervals rather than three, to ensure material is not too large.
Clearly, there is still more work to be performed, but the SAC is keen to seek alternative storage and transport systems for coppiced material. *