The best way is to buy a small gasoline generator.
And then you buy 12 gas cans. Label them Jan-Dec. Each month, you pour one of the cans into your car's gas tank, and go get it refilled. Thus, you are continually recycling your storage. (Gasoline separates and becomes gum and volatiles; not good for engines)
Then, when the lights go out, you have 12 cans of gas to use on your little generator. Should get you through almost anything.

Another way to go is buy a propane powered generator. But they are much rare in the states. Propane doesn't degrade like gasoline, so you can just store several cannisters for when you need them. Also good for cooking and such.

Solar power, you start with whatever panels you can afford. Then a small charger and a battery. Then you buy a little inverter, and run shit off it.
Then, you just make the whole system bigger.