Science Centres: Energy

New Zealand’s bioenergy research

Wood pellets made from sawdust or shavings can be used for domestic heating or by larger energy consumers, such as hospitals, schools, and hotels. (Photo: Scion)

Overview by John Gifford, GM Sustainable Consumer Products, Scion

Bioenergy is the energy derived from the conversion of plant material (woody material, grasses, crops, oils, algae, solid wastes, and effluents) to provide heat, power, or liquid fuels.

Bioenergy currently provides about 5% of New Zealand’s total primary energy supply, primarily from burning wood processing residues or lignin liquors from part of the kraft pulping process used in the manufacture of paper. Research into the use and potential of bioenergy has been undertaken at Scion (previously Forest Research) in collaboration with other research organisations, including CRL Energy and Massey University.

This research has focused primarily on:

• the description of biomass resources
• evaluation of conversion systems (with an emphasis on heat and power)
• identification of the social and environmental benefits of bioenergy
• options to upgrade biomass fuels so they can be used for a broader range of markets and applications (e.g., wood pellet fuels)
• modelling of energy demand and optimisation of system performance to provide energy cost-competitively
• participation in IEA Bioenergy, an international research collaboration of 23 OECD countries focused on reducing barriers and improving the deployment of bioenergy

This research has markedly improved New Zealand’s understanding of the potential role of bioenergy and reduced the costs of providing energy in some situations, particularly industrial and domestic heating.

The main outcomes of this research to date include:

• databases on fuel quality of various biomass resources, including moisture content, particle size, ash content, chemical composition, and ash‑forming properties – information required when considering use of these fuels for generating heat
• understanding of the mineral formation processes during combustion identification of the social and environmental benefits of bioenergy again required when considering the use of biofuel
• quantification of New Zealand’s woody biomass resources (about 4–6 million tonnes per year) and infrastructure requirements to support these
• development of fuel management systems to reduce the cost of forest-derived residues from around $4/GJ to approximately $2/GJ
• promotion of the wood pellet industry through detailed resource assessment and evaluation of the potential demand for wood pellets
• development of a Bioenergy Knowledge Centre in collaboration with the Energy Efficiency and Conservation Authority and the Forest Industry Development Agenda