To reduce the storage needs, I think most people could be flexible with their power usage during emergencies, high prices or bad (local) production. For example

To reduce the storage needs, I think most people could be flexible with their power usage during emergencies, high prices or bad (local) production. For example, I can typically postpone big-screen movie nights, doing the hoovering/laundry, cooking in the (electric) oven, heating the (electric) sauna. For one day every now and then, it's no problem to turn off the convenience heating of the bathroom floor either. You can check your power consumption during sleeping hours to get a base level. Then, on a normal day, I use 3 to 10 kWh but can fairly painlessly cut it down to 1.5 kWh if needed, which would be more feasible to store in a battery.