No renewable enthusiast or project promoter I know ever wants to go into such calculations. They literally run away from them. We could generously assume that they don’t know about such things but in this case, they would stay put convinced that they would carry the day in any discussion. The fact that they avoid them more than the devil shuns holy water proves that they know they are selling snake oil and fully expect us to lap it up like ice cream.
At current prices of around $200/KWH the 560 GWH of storage will run around $112 billion, or around half of the annual budget of the state government of California.