Devil's advocate - for 20 years you've had the opportunity to come up with another method to have power, and haven't?
We have the solution. It's cost effective and works reliably. No reason to search for another solution until the tech can catch up.
Battery banks are cool, like the Tesla Power Wall. Let's do some quick math:
Peak Power & Capacity Requirements
A common generator is 5kW peak output. Let's say it runs at 3kW average to keep the house running. I think this is a fair estimate for a family with some appliances/computers/lights on. If we are conservative and only running the bare minimum to keep food from spoiling, maybe we can reduce it to 1500W (a single power outlet capacity) Let's say the power is out for 2 days at a time consecutively (not uncommon). That's 72 to 144kWh.
The PowerWall 2 has 13.5kWh of energy capacity. Therefore it would require would need 5 to 10 of them to last for the 48 hours.
Initial Cost
A generator costs anywhere from $700 to $4000, for the cheapest home-depot special to an ultra quiet Honda, respectively. A single Power Wall costs $10,500 if you don't have a solar system installed on your house, so $52,500 to $105,000 initial investment.
Energy cost
A 5kW generator consumes about 3/4 gallon per hours of running. At $4.50 a gallon, that's $162 for the 2-day time period. A power wall will need to be charged. Power costs about $0.16/kWh and there is probably a 90% charging efficiency. Charging the power walls to last 2 days will cost $13 to $26.
I could probably make a graph of the return on investment crossover point, but I don't know the data on battery degradation. The power walls have a 10 year warranty, and are probably down to 85% capacity at that point. In 20 years, it might be down to 70% initial capacity.
Let's day the power is out for 10 days a year (PG&E forced outages plus storm damage)
Initial Cost: Generator $2000, Power Wall $52,500
Yearly Cost: Generator $810, Power Wall $65
Year 10 Total Cost: Generator $10,100, Power Wall $52,825
Year 20 Total Cost: Generator $18,200, Power Wall $53,800
Crossover: 68 years
Someone correct my math if it's wrong I did this kind of quickly...
I will happily adopt electric energy storage when it becomes feasible but we aren't there yet, and won't be there in 2024 or even 2028.