[Ammit]

Nice ideas but, I am somewhat confused.

Having read previously that we may be under water, not just britain, would underground be a good idea.

If you were high in mountains then obviously you would be able to use caves, if any but you would be limited by the size of caves as rock being harder then soil to manipulate.

Besides the fact that what I read stated that there would be no place to hide as searches can be done even underground. So how would you hide yourselves?

The air filtration, well, another unknown as we would not know what exactly would be in the air, i dare say a stacked system of scrubbers would help.

A charging system is a fantastic idea, as long as the air supply is good and circulatory, batteries give off a lot of toxic gases when charging, so maybe better to store batts outside to reduce problems.

Solar??, small fans run from a 6v system could help circulate air with little maintenance. I also read there would possibly be high winds, so why not use it for power instead of a power driven item to create power. I have done a fair bit of research on wind power and rather then use a turbine, which if not self furling can cause problems, instead use a drum turbine.

Sorry for yapping, but just a few thoughts.