New Zealand Energy Flashcards
What is New Zealand’s energy mix?
In 2014:
80% of energy production was through renewables; mainly HEP, geothermal and wind energy.
40% of energy use came from renewables.
Aims for a 90% renewable energy production by 2025.
What are the 7 sources of energy in NZ?
HEP
Geothermal
Wind
Coal
Gas
Oil
Nuclear
New Zealand HEP:
Provides 57% of NZ energy.
The very mountainous south island with high rainfall allows for 3 major HEP schemes and the north island has another 2 schemes.
South island has many lakes, rivers and yearly snow melt helping with HEP.
Climate change may restrict the effectiveness of HEP and require further flooding to keep up with energy demand which has already been met with public pushback.
New Zealand Geothermal:
Located on a destructive plate boundary so has significant geothermal energy potential.
New Zealand Wind:
Wind is the fastest growing source of energy in NZ contributing 5% in 2014.
Particularly strong westerly winds between 40-50 degrees south (Roaring Forties) allows for the north island especially to exploit wind energy. This is where 70% of the wind turbines are across NZ.
Estimated to possibly supply up to 20% of NZ’s energy is there is enough investment but there is pushback due to protecting NZ’s natural beauty.
New Zealand Coal:
NZ does have coal reserves but it is cheaper to import Australian coal due to its limited demand which boosted coal use until 2006.
Coals energy production peaked in 2006 at 5% and fell to basically 0% by 2012, only used as a reserve when river levels were very low so HEP was less effective.
In 2015 the last 2 coal fired power stations were announced to be shut down by 2018.
New Zealand Gas:
NZ is self-sufficient in gas from the Taranaki Basin but this is rapidly depleting and so cheap gas is likely to end soon.
In 2014 geothermal energy overtook gas as the 2nd largest source of energy and it is likely many gas fired power plants will be mothballed so they can be quickly put into use in the future.
New Zealand Oil:
The largest energy demand by NZ is oil.
Domestic production supplies 47% of its needs.
Imports are likely to increase significantly as its reserves are rapidly depleted.
Oil is no longer used for electricity generation but is used to heat homes and as fuel for transport and agriculture.
New Zealand Nuclear:
Declared nuclear free zone in 1987.
No current plans to build nuclear power stations and rarely considered.
However, legislation doesn’t directly prevent the construction of nuclear power stations.
Where is Waikato?
The Waikato district is located in the north island and is a hub of renewable energy.
What are the main energy sources in the Waikato District?
Wind - Lies in the middle of the roaring forties.
Geothermal - SE end of the district is an ancient super volcano caldera.
HEP - Relief rainfall and NZ longest river.
How is geothermal energy captured in the Waikato District?
Over 50 production wells boring between 0.3 to 2.4 km deep and producing fluid at temperatures over 210 degrees C.
4 separate power plants generating 333MWE (2014).
The created fluid is a mix of pressurised water and steam, with the waters heat creating energy and the pressurised steam spinning turbines.
The less pressured steam heats pentane, a low boiling point liquid, which evaporates and moves a further turbine.
What is done with the excess water?
43% of the hot water is reinjected into the ground to prevent cold water taking its place and cooling the groundwater.
Once the water has cooled it is discharged into the river to maintain river levels for HEP energy.
