In 2005 coal contributed about 10% of New Zealand‘s electricity supply and 12% of its primary energy supply. It seems likely these proportions will increase. The environmental obstacles to new large-scale geothermal and hydro development schemes, the high cost of other renewable energy sources and imported oil, and the failure to discover large new gas fields in New Zealand make coal a major option for a secure energy supply at a reasonable price.
New Zealand’s industries need low-cost energy to remain internationally competitive. New Zealand has large resources of coal in several regions and will be able to supply a high proportion of the non-transportation energy requirements for hundreds of years at a reasonable cost. The lignite resource has the potential to supply transport fuels economically as world oil prices increase.
Coal is widely perceived to be a polluting fuel, but in developed economies this perception is largely a hangover from the belching images of smokestacks of the industrial revolution. Pollution from smoke and soot was largely under control by the end of the 1970s, and by the 2000s environmentally acceptable levels of sulfur dioxide and nitrogen oxide emissions were readily achievable at ever-reducing costs.
The main concern surrounding increased use of coal is its contribution to atmospheric concentrations of carbon dioxide – a cause of potentially adverse climate change.
Coal cannot be burnt without producing carbon dioxide. Because coal is such an important energy source worldwide, massive efforts are being made by many countries to find ways to reduce or eliminate emissions. These focus on:
- carbon capture, which involves the removal of carbon dioxide either directly from the exhaust streams of industrial or power plants or indirectly from the atmosphere
- carbon sequestration, which is the disposal of carbon dioxide in a natural storage compartment such as depleted underground oil or gas reservoirs.