Edition 3, Revised 18/10/2016
Western Australia is our largest state with a land area of 2,529,875 square kilometres. It has around 2.6 million people, or 11% of the national population. With its small isolated population and without any grid connection to the remainder of the nation it has unique challenges in establishing low carbon generation
There are two large electricity markets in Western Australia: the North West Interconnected System (NWIS) and the South West Interconnected System (SWIS). The two systems are not connected electronically. Additionally there is a significant resource sector generating capacity that is not interconnected.
The capacity of these systems in 2014[i] is listed in Table 1
|System||Rated Capacity 2014 (MW)||Main fuel|
|North West Interconnected System (NWIS)||554||Gas|
|South West Interconnected System (SWIS)||554||Biomass, Landfill Gas, Solar Photovoltaic, Wind, Wind/Diesel|
|5440||Coal, Coal/Gas/Diesel, Gas, Gas/Diesel|
|Non-interconnected systems (Off grid)||3341||CNG/LNG, Diesel, Gas, Gas/Diesel|
|49||Hydro, Solar Photovoltaic/Diesel, Wind, Wind/Diesel|
Table 1 – Western Australian Generating Capacity – 2014
Ninety two percent of the population is concentrated in the south west corner where they receive power from the South West Integrated System (SWIS).
While the state generated a total of 32 TWh of electricity in 2014-15[ii] the SWIS in the south west delivered approximately 18.7 TWh of electricity[iii] or about 59% of the state’s total. In 2011-12 the NWIS generated 2.47 TWh and 6.4TWh in the off grid sector. The numbers vary between years and cannot be reconciled for one complete year.
BREE estimate that Western Australia will increase its 2014 generating total from 32 TWh to 46 TWh. On a proportioning basis, the SWIS and NWIS would grow from 21.17 TWh to 30.4 TWh by 2050
In the SWIS is about 91% of electricity is generated by fossil fuels with coal at about 50% and gas at 41% while in the NWIS the fossil fuel amount is closer to 99%.
Large Reactor Option – Not favoured
If AP1000 sized reactors were used then by 2050 Western Australia would require:
For the purposes of this plan this would require a total of six reactors with a generating capacity of 6.7 GW plus transmission upgrades and energy storage.
This option would incur large costs as a result of trying to “shoehorn” large reactors into a small energy system and is not investigated further at this stage.
Small Modular Reactor Option – Better Option
Clearly a small self contained grid such as Western Australia’s will require backup capacity to cope with reactor trips and refuelling. Smaller reactors in the sub 300MW class such as the proposed SMR’s would be a better fit. They would overcome the impacts of refuelling or reactor trips and would mean that the grid would not require such extensive upgrades and energy storage can be avoided.
Unfortunately SMR’s are not currently available. Significant development is taking place in the USA, UK, China, Russia and South Korea.
Currently one of the more advanced SMR’s being proposed and closer to licensing approval is the Westinghouse 225MW SMR. The business case for SMR’s is reliant upon mass modular construction, a significant order book and at least two decades to availability.
If 225MW small modular reactors were used then by 2050 Western Australia would require:
For the purposes of the plan we will work with a total of 31 SMRS with a generating capacity of 6.98 GW. The following table shows seven regions of interest that could contain these reactors.
|Region of Interest||Location||Feature||Siting||Cooling||Comment|
|1||Geraldton Region||Coastal or Inland||Stable rock foundations||Once through sea water or hybrid air/water cooling||Grid upgrade required.
Assumes minimum plant size 2 x 225MW SMR’s = 450 MW
|2||Perth Region||Coast and Inland
Replacing Kwinana, Cockburn and Pinjar Generators – 1642MW replaced
|Stable rock or non rock foundations||Once through sea water or hybrid air/water cooling||Grid upgrade required. Assumes minimum plant size 12 x 225MW SMR’s = 2700MW|
|3||Collie Region||Inland||Stable rock foundations||Hybrid wet/dry process.||Modest grid upgrade, close proximity to existing Collie region power stations. Assumes minimum plant size 9 x 225MW SMR’s = 2025MW|
|4||Kemerton||Replace Wagerup Gas Power station||Stable rock or non rock foundations||Hybrid wet/dry process.||Assumes minimum plant size 2 x 225MW SMR’s = 450 MW|
|5||Margaret River||Coastal Location, requires extensive grid upgrade||Stable rock foundations||Sea water cooling||Assumes minimum plant size 2 x 225MW SMR’s = 450 MW|
|6||Albany||Coastal Location, requires modest grid upgrade||Stable rock foundations||Sea water cooling||Assumes minimum plant size 2 x 225MW SMR’s = 450 MW|
|Coastal Location, requires modest grid upgrade locally and large interconnector to SWIS||Stable rock foundations||Sea water cooling||Assumes minimum plant size 3 x 225MW SMR’s = 675 MW|
[i] WA Dept of Finance – Generation website
[ii] Australian Energy Projections, Bureau of Resources and Energy Economics
[iii] Table 8 Sent Out Energy Forecasts, SWIS Electricity Demand Outlook, Independent Market Operator
[iv] Fig 30, Sent Out Energy Forecasts, SWIS Electricity Demand Outlook, Independent Market Operator
In Western Australia coal fired plants were constructed adjacent to available coal mines and other infrastructure.
New nuclear plants will where possible take advantage of the resource used for cooling at these plants.
In an effort to reduce the environmental impact upon inland water resources, modern nuclear power plants are being designed to use a hybrid system of air and water cooling. During periods of low water availability the degree of air cooling can be increased though at a modest reduction in power output.
At coastal plants such as those in the Geraldton, Perth, Pilbarra, Margaret River and Albany regions, sea water would be the sole form of cooling.
The tabulation shows the anticipated type of cooling at each plant
Western Australia’s long coastlines provide many options for locating nuclear power plants
While recirculating systems don’t add heat to the river or lake, they do consume water through evaporation. In Western Australia the availability of sizeable inland rivers are limited and so to overcome issues surrounding temperature rises in inland locations mechanically driven systems known as hybrid and recirculating systems can be used. These are now the only option used in the United States under their EPA guidelines.
An excellent and detailed outline of the cooling options is available at: Cooling Power Plants | Power Plant Water Use for Cooling – World Nuclear Association