Tesla has charged $10K for an extra 25KWH combined with a $2K supercharger. That means that it is 8K for 25KWh, or $320 / KWH. Now, that was 3 years ago.
Since that time, Panasonic has since added more production lines, and more shifts. At this point, in another 2 years, Panasonic expects to have their equipment paid for. And you can bet that Tesla does NOT pay 320/KWH, even 3 years.
Point is, that when Tesla finishes their gigafactory in less than 2 years, they are suggesting that they will be less than $100/KWH.
Now, the interesting part is that when Tesla's Model 3 comes out and is less than 35K WITHOUT SUBSIDIES, it will cost less than the average ICE car that is bought. If the Model 3 is even close to the quality of the Model S, this will destroy every ICE sedan that costs 20K on up. The reason is that owning an EV is a fraction of the costs of an ICE. And compared to OLD ICE vehicles, it is MUCH CHEAPER. So, this will destroy not just new ones, but also kill the resale value of older cars. As that happens, panic will set in to automakers AND the owners. This will likely lead to companies like Honda, Toyota, Audi, MB, VW, GM, Ford, etc will see their sales, profits, and stock prices PLUMMET. And esp. for the German and Japanese whom are pushing hydrogen cars, which are pure junk.
Finally, EVs with more than 150 MPC will be charged every night, and most will not need a daytime charging. Here in Colorado, Xcel charges .12/kwh for daytime, and only .055 for nighttime. That price makes EVs a FRACTION of the costs of ICE (GGE to .80 on a 30 MPG car).
And multiple studies have shown that electrical generation and grid are FINE for 100% of all vehicles, as long as less than 25% of them charge in the daytime.
In addition, the studies have shown that it will actually save utilities billions since they will not need to run expensive on-demand systems and can go with nukes and other decent choice base-load power plants.