There are several answers to this. The three that stand out to me are alternate power generation methods (inferior, but still helpful), designing systems with excess battery capacity, and, you know, using less energy at times when it's harder to generate.
People tend to be dismissive about conserving energy, but I expect they would think differently if they were producing & storing their own. We use way more than we need to-- some of the biggest power hogs are air conditioning and refrigeration, neither of which is necessary in the winter.
My point is: how expensive would it be to have alternate power generation, especially in cities? I think the grid isn't going anywhere anytime in the next 50 or 100 years at least.
It's anyway going to be an awful long time before North America stops burning fuel for winter heat.
I guess something like $500 a year is not a welcome new bill, but that would be the cost for replacing a house sized generator at a pretty short interval. If the duty cycle is low and maintenance is effective I would expect the cost to be lower than that.
People tend to be dismissive about conserving energy, but I expect they would think differently if they were producing & storing their own. We use way more than we need to-- some of the biggest power hogs are air conditioning and refrigeration, neither of which is necessary in the winter.