After some costly experiments, I have concluded that a horizontal wind generator is all wrong for a civil defense application.
Here are just a few of the merits of a VAWT turbine:
Easy construction using just about anything. VAWTs can be build from plastic buckets, PVC, metal pipe, anything that is a cylinder that can be cut. The design is elegant, simple enough for any layman to understand in seconds and therefore easy to repair and replace when it becomes necessary. If the post apocalyptic world has any cylinders left in it, you should be able to build as many VAWTs as you need.
Tough enough to easily withstand conditions that would wreck a regular wind tower, even 300 mph winds. It is hardy enough to last through extreme conditions of all kinds with a longer life and lower maintenance requirements.
It is self damping in speed to avoid many of the problems associated with rotors in wind towers, meaning it is safer to operate and puts less stress on the structure which can be located closer to the ground. It has fewer moving parts to wear out, in any event. The only cost is a slightly reduced efficiency but the gain is very large.
Requires no vane to point it into the wind, which also means no slip rings! Trying to locate slip rings was one of the things that drove me to investigate VAWTs as an alternative. Slip rings are ridiculously expensive and therefore prohibitive in a system for which robustness is the primary requirement. The VAWT spins in any wind strong enough to turn it, irregardless of direction.
It can be protected from the elements, housed in a safety cage and sealed against ice, rain, moisture and grit that represents a serious degeneration over time for any instrument that relies on moving parts. It can be anchored more firmly and even camouflaged where a regular wind generator cannot be.
Check out the link to the plans and also have a search for "Savonius" wind generation. I think the alternate vertical designs may be more efficient but they are as fragile and vulnerable as the horizontal wind towers for a variety of reasons. The Savonius design looks like the way to go, although it may be optimal to have several vanes on the drum as opposed to two. I will have to do a bit more research.