Whether you're planning for the apocalypse or "just" worried about the likelihood of an extended power outage, you're going to need to eat in the event that disaster strikes.
Any perishable stored foods won't last long if the power goes out, so your normal supplies won't last long. What you really need to consider is some form of emergency food supply, which is long lasting and well protected.
Here's a list of some of the readily available emergency food kits on the market. Most of these have a shelf life of at least five years, some of the kits are rated for 25 years.
Hopefully this is something that you will never need to use, but it pays to have some form of insurance. Better safe than sorry after all.