The Storage Module allows the base to store larger quantities of Helium-3 and Mineral Ore.
— In-Game Description
Storage modules are used to store player's Helium-3 and Mineral Ore. They do not store any antimatter resources. If you are attacking a base, you can target and specifically destroy these base modules to steal additional resources.
Destroying combat modules yield no resources, destroying miner modules can provide minimal amount of resources, destroying their bridge also yields resources and medals. Player's fleets can steal resources up to five times their maximum storage capacity.