Making PJM all wind and solar would cost over $2.4 trillion in battery backup

I keep reading how big batteries are all it takes to make wind and solar reliable as the sole grid electricity source. - David Wojick

• The reality is that making wind and solar work at all requires a fantastic amount of battery backup, far more than is possible.

Below is an example using the PJM grid. 

PJM is America’s biggest grid operator, with a territory covering the Mid-Atlantic and points west...
My example year is 2030, as that is a standard near-term transition target year for which we have reasonable estimates of peak demand. 

Here then are the very simple numbers.

• PJM’s estimate peak demand for 2030 is about 180,000 MW.
• Meeting that for 16 hours with batteries requires 2,880,000 MWh of usable storage.
• Usable storage is between 20% and 80% of nameplate battery capacity, hence 60%.
• Thus we need 4,800,000 MWh of nameplate battery capacity.
• Storage facility capital costs vary, but $500,000 per MWh is a reasonable estimate.
• This gives a total cost of $2.4 trillion, or $2,400,000,000,000, for the batteries to make wind and solar reliable in this case. 

This fantastic cost is clearly not feasible...