California requires cruise ships, and other ship-types, to use shore power. I'd think this infrastructure would mean higher port taxes, and required cruise companies to outfit their ships with compatible infrastructures. Below is from August, 2020.
The US California Air Resources Board (CARB) has expanded a regulation on the use of shore power by ships while at berth to include more types of vessels.
The updated regulation has added auto carriers and tankers, two categories that produce 56% of all fine particulate pollution from ocean-going vessels at berth in California ports.
At present, the vessel types covered under the existing regulation include containerships, reefers and cruise ships.
Shore power, or cold ironing, allows ships to get their power from electricity and stop burning bunker fuels while at berth, helping to reduce harmful emissions such as particulate matter, nitrogen oxides, sulphur oxides, and greenhouse gases.