As a start and as best as I can find the 2020 Build cost is:
Coal (Black HELE) =$3,370/kw (Electranet), Wind = $1,982/kw (AEMO), Utility Solar $1,349/kw (CSIRO)
If we want to produce 850 MW then the installed capacity required is:
Coal - 1,000 MW (Capacity Factor of 85%)
Wind - 2,429 MW (Capacity Factor of 35%)
Solar - 3,400 MW (Capacity Factor of 25%)
From the above the Cost is: Build Cost / kw x 1000 x Installed Capacity
Coal = $3,370,000,000
Wind = $4,696,857,000
Solar = $4,586,600,000
Depending on the required outcome we can change the capacity factor to achieve any desired results.
As more capacity is added then curtailment will be required or storage losses and installation costs included. Any curtailment, Storage losses and marginal loss factors will affect the capacity factor.
Note: The build cost numbers come from reports and models in the below links, I've ignored connection costs and backup, the rest is my workings and opinion and I suspect the numbers will also vary by state and location.
CSIROAEMOElectranet
