Do PSU caps degrade when not in service?

[VirtualLarry]

I have stockpiled a number of brand-new PSUs. Are the caps in those degrading, simply over time, or do they degrade only from usage?

 

[Arcanedeath]

They do degrade with time, but not anywhere near as much, Heat is caps bigest enemy

 

[PM650]

They do degrade with time, but not anywhere near as much, Heat is caps bigest enemy

This. A general rule-of-thumb is that components last twice as long for each 10ºC decrease in temp (i.e. half as much degradation over time, for components that do degrade).

Although, my immediate experience with JunFu caps is that they'll die from a few years of complete non-use ; would hate to think how long that supply I had would've lasted in service...