Value chain analyses of whole crop harvesting to maximise co-generation.

WHOLE CROP harvesting to maximise co-generation requires a substantial change to the sugar value chain and substantial investment. Thus, careful analyses are required. Cogeneration of electricity can be maximised by harvesting the whole crop, i.e. using the additional fibre in tops and trash to fuel cogeneration. However, whole crop harvesting will have impacts on the whole value chain which will be very difficult to predict a priori. We worked with stakeholders in two mill regions to assess, through novel supply chain modelling techniques, the viability of options for co-generation maximisation within locally defined constraints relating to preferences for using existing or installing new power generation capacity. The modelling used agent-based approaches to facilitate integration of existing single-sector models into a whole of value chain framework model. Income from electricity and Renewable Energy Certificates sales was weighed against not only the costs of constructing (for some scenarios) and operating the co-generation facility, but also the costs associated with loss of trash from the field, harvesting the whole crop and transporting it to the mill, separation of trash from cane, and the impact of increased extraneous matter on sugar milling. In general, predictions of the impact of losing trash from the farming system were greater than anticipated, while the impacts in the harvesting and transport sectors were less than expected because of increased efficiency that might be achieved in these sectors. The analysis provided a more complete understanding of the possible impacts of whole crop harvesting than previously available, or than would be obtained using more traditional assessments. The analysis also provided other benefits, such as defining the value of trash and tops and possible improvements in harvesting and transport logistics, which are being used to improve the sugar value chain in the case study regions.