An off-grid solar (photo-voltaic) electric power system is an ideal prep for modern survival in that it can partially or totally relinquish you from dependence upon other systems, which themselves are vulnerable to disruption or breakdown.
Off-grid systems also enable the ability to live away from the mainstream, which opens the door to properties which may be more affordable than others which require connectivity to public utility systems.
Even if living in suburbia, installing an off-grid system side-by-side with the existing electrical system could provide you with a completely separate electrical circuit (separate outlets, etc