Wood energy resources in New Zealand

Abstract

A methodology was developed to assess the current utilization of New Zealand's Wood Energy Resources. A preliminary use of this methodology indicated that at least 1,164,032 m³ of wood was used as an energy source during the survey year. Sawmills and chipmills were the source of 71% of this wood. Industry used 56% of this wood. From this wood was derived 9.5 petajoules of total energy and 2.2 petajoules of effective energy.

A preliminary assessment of New Zealand's potential Wood Energy Resources indicated that these resources are grossly under-utilized. Energy farming could annually provide up to 200,000,000m³ of wood. This amount of wood could provide double New Zealand's current energy requirements. During 1977 residues (8,000,000m³) and conventional forestry stocks (10,000,000m³) could have provided smaller amounts of wood.

New Zealand's Wood Energy Resources are not only huge but their use is comparatively sustainable. A further advantage is that these resources can be converted to a wide range of energy products including electricity, solid fuels and transport fuels. Currently the only economic option appears to be the use of residues as solid fuels. In the near future the use of wood derived transport fuels will probably become economic. The net energy gained by converting wood to transport fuels is probably very small and is certainly less than the other systems for producing transport fuels. Any large scale development of these resources is likely to have extensive environmental costs, although they could have beneficial regional development effects.

The use and development of these resources should be based on the rational application of sound management principles so that the short and long term needs of New Zealand Society are best served.