Have you ever been to Long Beach CA? Take a look at the (frequently) dozens of containter and tanker ships idling just offshore. Any major port city will have the same issue, transport ships waiting, for various reasons, just outside of a port with their engines running. Any refrigerated cargo needs to be cools, which requires power, which means that they run 24x7 while sitting around.

there was a push to improve shore-power options for these ships a while back, but i'm not sure where it went. probably deemed to costly or intrusive by the shippers.