You are vastly underestimating the cost and complexity of running this system at an affordable cost. You would end up with Tesla running the majority of your f

You are vastly underestimating the cost and complexity of running this system at an affordable cost. You would end up with Tesla running the majority of your facility (by cost), and consequently would not be a competitive plant. Let's do some simple math: An average natural gas plant seems to be around 800MW, and we might assume that they are running somewhere around 1/2 capacity when there is not much solar irradiation (evening and night), giving us an average power level of 400MW. Wikipedia says that Lithium Ion cells have a specific energy of about 100-240 W.h/kg, and I'll assume that Tesla uses some good 200W.h/kg cells. If the plant has to run with no irradiation for 10 hours at half capacity, it needs 4000 MW.h of energy in batteries, which is 4000M/200 = 20Mkg of batteries not including any losses during discharge or wasted energy for cooling. 20 million kilograms of batteries would be very expensive to store and maintain; they would also take up a lot of containers. A 20' container is usually maxed out at about 20 tons, so you would need a thousand of them. The basic problem is that unlike molten salt, there are no economies of scale to be had with batteries or photovoltaic panels.