Well, that's ~100 kWh per car on the road in Ireland, or about the capacity of a full Tesla. The transition to EVs is going to go hand in hand with the transition to renewables, because then you've got a significant amount of demand you can switch on and off at will (or run in reverse, in the case of battery to grid systems).

The future will probably look something like: under normal use, you set your 100kWh car to be able to use half of its battery for grid stabilization, and in return receive charging at perhaps 1/4 the standard price. If you're planning a longer range trip, you turn that off and your full battery is waiting for you.