Geothermal Resources

Download Factsheet: Geothermal – the Earth’s energy (pdf)

New Zealand is fortunate to have an abundance of geothermal resources. We often think of Rotorua as a classic example of an area with lots of geothermal energy. In Rotorua, the geysers, hot pools and boiling mud are created by relatively shallow volcanic activity.

However, there are other types of geothermal energy that are less obvious, available throughout New Zealand, and with the use of a geothermal heat pump, can provide an efficiency, reliable and renewable energy source.

These resources are created by two processes.
  1. Solar radiation is absorbed by the Earth’s surface and then stored in rocks, earth and water.
  2. Heat flows from the hot interior of the earth to the surface along a natural temperature gradient. This temperature gradient (hotter the deeper you go) is estimated at about 3oC/100 m in New Zealand.

Combined, these processes mean that ground, groundwater and surface water maintain a more constant temperature than air throughout the year. Geothermal heat pumps take advantage of this fact.