i think this has been requested before, if so, i reinforce that idea
here it is, its a combination of Consumable resources and Static. essentially, the resource is produced (like at a building), and it is added to the stockpile. when something requiring that resource is needed, it is just taken out of the stockpile. this is different from consumable resources in that if you have 0, your guys wont die, you just have to wait until you have enough.
this would make a certain resource infinite, you are only limited on how much you can bring in.
see what im saying?