Bioenergy Opportunities from Forests in New Zealand

Abstract

An analysis on New Zealand’s bioenergy resources found that plantation forest derived and other wood residues are the largest bioenergy resource now and into the future (2040).

New Zealand’s forest and wood processing industries are based almost entirely on intensively managed plantations (~1.75 million hectares) of introduced species (Pinus radiata (89 %)), Douglas Fir (6 %) and a mixture of other species including eucalypts (1.5 %). The location, productivity and age class distribution of the resources is described in a national dataset, allowing prediction of future harvest volumes.

From the data available it is possible to determine supply trends at a national and regional level. There is a clear increase in wood supply between 2010 and 2030. Given the mix of logs that will occur, a large increase in the volume of chip grade logs is expected (up to 3.0 million tonnes per annum). Further, there is not expected to be a commensurate increase in uptake of these logs by the pulp and paper or reconstituted panel industries.

The highest priority for New Zealand in terms of fossil fuel substitution is liquid fuels for transport, and specifically a drop-in diesel. We have other options for electricity and heat production. Given that 97.7 % of our existing plantation resource is softwood this presents challenges for some biomass to liquid fuel conversion routes, such as enzymatic hydrolysis.

The volumes of residues and pulp logs potentially available could theoretically produce sufficient volumes of liquid fuels to meet 5–6 % of total liquid fuel demand or 15–16 % of diesel demand.

Studies of the potential for forestry derived bioenergy found that there would be significant environmental benefits from establishing a larger forest resource on low productivity hill country grazing lands, and that this resource could provide a very substantial part of New Zealand’s future liquid fuel demand.