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• Biomass production potential of mallee (2-6t/ field ha) is very low when compared with sugar
(80-150t/ha). This has an impact on vehicle utilisation and efficiencies.
• Sugarcane has to be harvested at optimum age and quality whereas the value of mallee product
does not change significantly. Mallee thus has less risk attached to harvest date.
• Traditional mallee field layouts comprise long alley lengths result in varying haul distance to the
loading pad which complicates infield haulage.
Harvesting, transport and storage systems
• High average sugarcane harvester throughputs of 100 to 150 tonne/hr are generally achievable,
versus 20-40 tonne/hr for the current prototype mallee harvester and an objective of 60-80
tonne/hr for subsequent prototypes.
• Sugarcane harvester field efficiencies (time spent harvesting as a fraction of the total harvest
time) are typically 30% to 50%. Efficiencies for mallee are anticipated to be much higher, 70-
80%, due to long belt lengths and low harvesting speeds reducing the number of times the
harvester needs to turn per hour.
• Sugar cane harvesting operations will typically deliver 50 to 60 tonne/hr (harvester pour rate by
field efficiency), versus 20 to 40tonne/hr for mallee. Low delivery rates result in higher costs of
harvesting given the general relativity in anticipated cost of equipment required in the harvesting
operation.
• Mallee biomass infield transport is also expected to be greater than for sugar cane due to the
larger paddocks and more dispersed resource.
• While bulk density data is limited, initial studies and experience in the WA wood chip industry
suggest that it is possible to achieve legal axle loads when utilising relatively standard transport
equipment. Thus, bulk density should not be of great concern to the mallee industry, with some
limitations.
• Mallee biomass is generally more difficult to move, tip and transport than clean sugarcane billets
based on its varied leaf, stick and chip in delivered material. This makes it desirable to minimise
the degree of transloading of the product during its progress from the harvester to the point of
initial processing.
• Separation on the harvester of leaf and chip will result in product losses in field. This is impacted
by the product required to be delivered to the processor which will depend on whether there is a
market for all products, especially the leaf.
• Greater reliability of biomass supply results in lower balancing storage. In the sugar industry
there are multiple suppliers and, generally, storage in rail bins, which helps balance supply. For
the mallee industry, stockpiles at the processing plant will be important. Processors operate 20 to
24 hours per day, seven days per week and 300 to 365 days per year. Harvest activities occur
during daylight hours and breaks for servicing are required. Initially, with a single harvester and
limited number of transport units, reliability will be low, adding to the requirement of stockpiles.
Storage life of material in stockpiles will be important
• Given long road transport distances likely and low value of delivered mallee biomass, savings
through full utilisation, maximum payload and quick turn-around time will be a pre-requisite, as
is found in sugar industry road transport systems.
Industry and Business Structures
• It will be difficult to get integration along a fragmented mallee supply chain unless key
participants (eg the processor or a transport contractor) see the supply chain as core business. The
sugar industry supply chain developed around regulation and rules to manage risk and industry
participants. Recent deregulation of sugar supply contracts has been based on an existing viable
business structure. The distributed ownership of the sugar supply chain has resulted in inherent
inefficiencies at the ownership interfaces.
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