Going to ground

Ground-source heat pumps are part of the wider heating system at Camp Glenorchy, where heat is stored in the form of hot water in thermal stores under buildings. The ground-source heat pumps make the most of the ground temperatures, which are more or less stable year-round. They work by circulating a fluid through buried pipes (Camp Glenorchy has nine 75 metredeep bores) and extracting heat from the ground, which is then transferred to the building using a heat pump.

To keep the cabins warm, hot water is circulated from these thermal stores (that look similar to hot water cylinders) through pipes installed under the concrete slabs. Heating water for the thermal stores is done using both the ground-source heat pumps and solar thermal collectors (mounted on rooftops).

While the use of ground-source heat pumps in New Zealand is increasing, growth is slow when compared to Europe and the US. Installing one is possible anywhere in the country, but they are more efficient in colder climates (in comparison to air-source heat pumps) due to the relatively stable ground temperatures.