Environmental energy flows in the New Zealand economic system

Abstract

An understanding of the energy basis for human societies is incomplete if the current and recent energy flows in the global system are not recognised. These contributions include sunlight, wind, rain, ocean waves and tides.

If, as we believe, mankind's long term future is constrained by the limits imposed by sustainable energy supplies, then we must acknowledge the relationship that exists between socio-economic systems and their supporting environmental systems.

For a long time people have recognised that the sun is an important source of energy supporting economic activity. However, some points of view have been advanced recently which discount the need to evaluate environmental energy flows and to include such evaluations in planning. Some argue that energy flows derived from current and recent solar energy inputs to the global system are beyond the sphere of interest of economic analysis since they do not have a money value. Such flows are beyond man's direct influence and the economic system regards them as "free goods". Others assert that such flows are so large that their inclusion in calculations dwarfs all other energy sources.

Much has been done recently to assess the validity of these arguments and to overcome the theoretical and practical problems in such energy analyses. Analysis based on the concept of Embodied energy now enables the assembly and interpretation of previously disjointed information to provide a more holistic view of the world in which we live.

This paper is a first attempt to rationalise and extend energy analyses of the systems of New Zealand by including environmental energy flows. The major flows are evaluated as annual averages and the relative utilities of the various flows are assessed in terms of their Energy Transformation Ratios.

The calculations provide preliminary estimates only and are described in detail to enable others to improve upon them later as better information and clearer perceptions evolve.