You are absolutely correct, current estimates for Snowy 2.0 is $12B. That is if you just want to put the power generated into a bucket and keep it on site. However there is the wee cost of connecting Snowy 2.0 into the grid.
I do understand your not including any of these costs (billions) as proponents such as yourself and squirrel food never do-it hurts the story if you have to include all of the costs.
One other little cost that needs to also be met to make Snowy 2.0 operate is enough power to push the water back up the hill (at present estimates are that it will take 137% more power to push the water up the hill than power generated but objective is to get that down to 125%)-this will be billions more required to make Snowy 2.0 work.
The total cost to actually make Snowy 2.0 operate I believe will be far north of $20B if all requirements are costed which NO renewable components will ever do.
