This is the third post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. Today we’ll be crunching the numbers on geothermal potential in New Zealand. For the background to the work and an explanation of the methodology, please visit this post. Also check out the last post on the potential of hydro power.
Unlike the UK, New Zealand has significant geothermal resources which currently contribute to national energy requirements. Geothermal energy has the advantage of being always available at full capacity, and unaffected by weather. Currently about 5.2kWh/d/p is available (3.6kWh/d/p of electricity is produced plus 1.6kWh/d/p in direct heating) but it is estimated that there is potential for a total of 12kWh/d/p at an admittedly higher price than gas generated electricity [dbpz7n]. Environmental and regulatory constraints further limit development. The Electricity Authority foresees generation rising by a further 4.4kWh/d/p by 2025 [9v5c9my] but little growth beyond that. Geothermal energy is low quality, producing lots of hot water for disposal. Ideally, better use of this hot water in co-located industry would improve overall efficiency.
Summary: There’s definitely potential here – but remember that even if we built every geothermal plant in the pipeline it’ll only ever make up about 8-9% of our overall energy supply.