At the Port of Seattle OPS was introduced for cruise vessels in 2005 by Princess Cruise Lines. The company fitted one berth with OPS and equipped two cruise ships with the necessary equipment.
The system can provide both 6.6 kV and 11 kV at 60 Hz, using a dual-voltage transformer to transform the 27 kV from the local grid. Because of the high power demand of cruise vessels, this system employs four high-voltage cables. These are provided by the terminal and so have to be hoisted onto the ships by crane.
Offering shoreside power was possible in Seattle because Princess Cruises invested US $ 1.8 million to cover the dockside costs and because Seattle City Light was willing to work with Princess and the Port of Seattle to bring power to the terminal. Shipside retrofit costs were US $ 1 million ($500,000 per vessel). City Light’s capital costs were offset in part by a US $ 50,000 grant from the US Environmental Protection Agency.
In 2006 a second berth was fitted with a similar OPS system, and three cruise ships operated by Holland America Line were equipped to receive shoreside electricity. The total cost of this shoreside power project at Port of Seattle was US $ 4.8 million, all of which was paid for by Holland America Line. Landside infrastructure costs were US $ 1.5 million and shipside retrofit costs US $ 3.3 million (US $ 1.1 million per vessel).
The OPS system is powered by a hydroelectric plant, which means emissions of both air pollutants and CO2 are effectively zero.