Storage structures provide huge storage containment for the resources produced by a planet’s mines. The three types of storage buildings are Metal Storage, Crystal Storage and Deuterium Tank. The higher the level of the storage facility, the more of that resource can be stored.
Initially, a new planet can store 10,000 units of metal, crystal, and deuterium. Once the storage capacity is used up, no more of that resource can be produced, regardless of the number of mines. To continue resource production, you will need to build another level of storage for that resource. A planet’s current storage capacity can be seen on the Resources screen by tapping any resource on the Menu Bar.