Biogas technology is considered the most efficient way to harvest energy from the sun that is stored in plants (in the form of cellulose, starch and sugars) as potential energy. Kiwifruit are regarded as a good feedstock for biogas production as they are high in sugar and are readily digestible.
A 2009 feasibility study, conducted by Bioform Ltd on behalf of ZESPRI, sought to investigate the lowering of non-renewable energy inputs within the ZESPRI value chain by using distributed biogas plants to recover the energy and nutrients from waste kiwifruit.
The study made comparisons between three different locations and configurations of biogas plants, with both greenhouse gas and cost benefit implications analysed.
Recovering up to 100 percent of the nutrients in the form of liquid fertiliser, this process reduces the orchard carbon footprint and the financial costs of imported fertilisers.
Two examples of the many opportunities to integrate biogas technology into the ZESPRI value chain, include:
- Replacing diesel and petrol with compressed natural gas for use in tractors, trucks, company and community vehicles, substituting fossil fuel consumption;
- Mixed kiwifruit / energy cropping;
- Kiwifruit biogas orchard - a biogas digester on a large orchard utilising reject kiwifruit only as a feedstack with no energy cropping; and
- Biogas packhouse - a packhouse located adjacent to a number of orchards for bio-fertiliser distribution.
According to Loren Poole of Bioform Ltd "there is considerable potential for use of biogas technology by ZESPRI to significantly reduce the carbon footprint of the industry."
Who is Bioform?
A company that specialises in kiwifruit orchard development and management as well as mechanical engineering consultancy in the fields of biogas technology, vehicle design and development.