Cold-ironing is the practice of shutting down auxiliary engines on ships while in port and connecting to electrical power supplied at the dockside to run on board equipment, thus eliminating virtually all emissions from a ship while in port.  Cold-ironing is also known as “shore power” or alternative maritime power. The term “cold-ironing” comes from the procedure of dry-docking a vessel, which involves shutting down all on-board engines, resulting in the vessel becoming “cold.”