Princess Ships Clear the Air with Shore Power Connections

June 9, 2014 /3BL Media/ - When Princess ships arrive at Juneau's South Franklin Street Dock every summer, vessels do something quite unique -- they turn off the diesel engines and literally “plug in” to the city’s own surplus hydroelectric power.  A similar process happens when ships visit other equipped ports.  

The first program of its kind in the world, Princess’ shore power program made history when it first began operations in the Alaska capital in the summer of 2001. The shore power hookup is the result of a multi-million investment to build a sophisticated power distribution system designed to help clear the air of accumulated haze in the port area. This ground-breaking technology has now grown to include systems in Seattle, Vancouver, Los Angeles, San Diego and San Francisco and is planned to roll out in other ports that have made commitments to shore power programs, including New York.

Shore power, also known as “cold ironing,” enables ships to turn off their diesel engines and connect to local electric power that travels to the ship from a specially designed transformer at the dock through a sophisticated system of cables, circuit breakers and control circuits. Shore-based electricity then runs all onboard services during the day-long calls.  

To create this unusual power system, Princess has outfitted 11 of its ships with a custom-built electrical connection cabinet that automatically connects the ship’s electrical network to the local electrical network ashore. The electrical power is transmitted from the transformer ashore to the vessel via 3 ½-inch diameter flexible electrical cables on the dock. (In Juneau, the cables hang festooning-style on a special gantry system designed to accommodate the 20-foot rise and fall of the tide and withstand the 100 mph Juneau winds during the winter.) The actual cable connection on the vessel is a traditional, though quite large, plug and socket.  

Since 2001, Princess has invested nearly $7 million in equipment alone to enable its vessels to connect to shore power. The 11 ships currently equipped with this technology include:
Coral Princess
Dawn Princess
Diamond Princess
Golden Princess
Grand Princess
Island Princess
Royal Princess
Sapphire Princess
Sea Princess
Star Princess
Sun Princess

The length of time needed to connect a ship to shore power and shut down the vessel’s diesel generator is approximately 40 minutes. Once connected, the ship’s engines are powered down and, simultaneously, the necessary amount of power, provided by local power companies, is used to run the ship’s services while in port.

Princess Shore Power Facts

Programs begun:
Juneau: 2001
Seattle: 2005
Vancouver: 2009
San Francisco: 2010
San Diego: 2010
Los Angeles: 2011

Estimated power usage onboard:
100,000 kilowatts/day

Estimated power cost:
$4-$5,000/day for surplus hydroelectric power (compared with approx. $3,500/day for diesel fuel if engines were used while in port)

Length of time needed to connect the electrical cables, parallel the ship’s diesel generator to the shore power, synchronize, transfer the electrical load and then shut down the ship’s diesel generator:
Approximately 40 minutes

Length of time needed to reverse the above procedure prior to departure:
Approximately 30 minutes

Ships to be equipped with shore power in the future:
Caribbean Princess
Crown Princess
Regal Princess