EV prices will keep on falling

 Battery costs continue to fall.  If anything, the rate of decline is accelerating.   

This has huge implications for EVs, obviously.  EVs will very soon have the same "sticker price" as petrol cars (they are already much cheaper to run).  EVs will rapidly rise to 100% of car sales.

But it also is crucial for de-carbonising electricity generation.   

Let's take a simple example.  Within the tropics (between 23 degrees north and south of the equator), we could run the grid entirely on solar.  For example, at Brisbane (latitude 27 S), in mid-winter (June), there are 10 hours and 25 minutes of daylight.  With tracking solar, which faces due east in the morning and due west in the afternoon, the output profile is "square", i.e., rises almost immediately to the maximum and stays there, compared with, say, rooftop solar, where the output rises in a sine wave to its maximum over a couple of hours over midday.  Demand at night is 2/3rds of demand during the day, so we would need something like 8 hours of storage.  If battery costs have halved, that means that 8 hours of storage will now cost what 4 hours used to.  

Outside the tropics, combining wind and solar and 8 hours of storage will be able to replace fossil fuels.  Only in high latitudes (north of 60 degrees), with long winter nights and high demand for heating, will we require seasonal storage (hydro or power-to-gas).  

Remember also, that EVs are storage on wheels, with the average EV having 70 kWh, or 3 plus days (72 hours plus) of average household demand (20 kWh per day).  This will be combined with several hours' worth of storage at every utility-scale solar farm, plus additional storage at substations to stabilise the grid.  

This video from the Electric Viking discusses the plunging costs of battery storage and its implications.