Losing power for 15 hours may (not) lose all of the food in the refrigerator/freezer, since as long as you keep it closed, will retain a lot of the coldness and much food is still safe to eat. Now lets say you just bought a half side of beef and froze it, then that would be a lot of meat you might lose. But odds are what you bought the prior day and what was left in the fridge maybe only a max of $200 dollars.
The problem with either renters or homeowners insurance is that once you make a claim (especially) if small like this one is, that you become a higher risk and your insurance would go through the roof when you renew or try and find another insurance company to insure you, only because you filed such a small claim.
Renters/homeowners, you only want to file for (big) losses, and if in a big loss like a fire/flood, then would throw in the loss of your food into the claim would make sense and not penalized as much for filing a claim.