NZ has been using Geothermal power since 1958. That power station now produces the largest quantity of power, (must have been expanded in 2008), compared to all the other Geo power stations. All up geothermal power production is 17% of NZ's power needs.
https://en.wikipedia.org/wiki/Geothermal_power_in_New_Zealand
https://www.nsenergybusiness.com/features/geothermal-power-stations-new-zealand/
The third-largest geothermal power station in New Zealand is Nga Awa Purua, which is another power plant based at the edge of the Taupo Volcanic Zone, in the Rotokawa field.
Named Rotokawa II, the NZ$430m ($308m) project was developed through a joint venture between Mercury Energy and the Tauhara North No 2 Trust.
Construction of the 140-MW capacity power station began in May 2008, with commissioning completed in May 2010. It now meets about 3% of the country’s electricity requirements.
Generating an annual output of 1,100GWh, which can power about 140,000 homes, the plant lies right beside the existing Rotokawa stage I power station.
Nga Awa Purua’s steam turbine is the world’s largest single shaft, triple flash geothermal turbine.
https://www.nzgeothermal.org.nz/geothermal-in-nz/what-is-geothermal/
Some extracted info...........Well worth a read. Especially the Geothermal Emissions drop box
The capacity of installed geothermal electricity generation worldwide is equivalent to the combustion of nearly 30 million tonnes of coal or the output of about 10 nuclear plants.
Geothermal energy is effectively a renewable resource, which does not consume any fuel or produce significant emissions. Although some geothermal fields have been degraded, none have been exhausted and sustainable development is possible. Geothermal energy also has the advantage, over other renewables, that it is independent of climatic variation.
The emissions factors for geothermal power stations in New Zealand for the calendar year 2018 are given in the table and figures below. These are the emissions of CO2(eq) released from the geothermal fluid during operation of the plant. The median emissions factor for 2018 is 62 gCO2(eq)/kWh and this is a standard measure of the central tendency of this kind of dataset with outliers. The use of the median (and other percentiles) is the same approach as used by the IPCC in the 2011 Special Report on Renewable Energy Sources and Climate Change Mitigation. Another useful statistic is the weighted average of 76 gCO2(eq)/kWh, which is weighted using the total energy generated from each plant, thus accounting for the fact that not all plants are the same size and hence their individual numbers for emission factor do not carry the same weight.
For comparison, the emissions factors from other renewable energy sources
during operation are:
- Hydro: > 0 gCO2(eq)/kWh (some methane is emitted from decomposition of organic material in the reservoir, though this is hard to quantify)
- Solar photovoltaic (PV): 0 gCO2(eq)/kWh (no emissions from sunlight)
- Wind: 0 gCO2(eq)/kWh (no emissions from wind)
And emissions factors from fossil fuel plants from fuel combustion
during operation are (national average NZ, source MBIE):
- Coal: 970 gCO2(eq)/kWh
- Natural gas (open-cycle gas turbine): 530 gCO2(eq)/kWh
- Natural gas (combined-cycle gas turbine): 390 gCO2(eq)/kWh
