The Netherlands this week introduced a new shore-to-ship power system at Rotterdam, part of an international push to reduce pollution from ocean-going ships.

The $3.5 million system at the Port of Rotterdam was activated Tuesday by Dutch Infrastructure and Environment Minister Melanie Schultz van Haegen, who cited it as a landmark in efforts by seaports to operate in a more environmentally friendly way.

"This means that ships that are berthed no longer need to keep their engines running to generate electricity," she said. "The result is that fewer hazardous substances are released so that the air quality in the surrounding area will improve considerably."

The system, installed at the Hook of Holland terminal, will be used to connect four Stena Line ferry ships to onshore power sources, thus cutting down on the sulfur dioxide, nitrogen oxides and fine particles emitted by diesel power generators while ships are berthed.

The Netherlands system, built by the Swiss engineering firm ABB, was paid for by the port and city of Rotterdam and the country's transport ministry but the Stena Line had to bear the cost of adapting its ferries, a decision that brought praise from Schultz van Haegen.

"I have great admiration for Stena Line," she said. "In stormy economic weather it has nonetheless invested in new sustainable technologies."

The city of Rotterdam was already using about 300 shore-based power connections for inland shipping such as river cruise vessels but none for ocean-going ships.

Port officials say there are no specific plans for more connections for sea-going vessels because of the costs involved. However, new quays and renovated older ones are prepared for future shore power, they said.

Ocean-going ships require electricity even when docked for amenities such as ventilation, lighting, heating and cooling. The heavily polluting generators they use pump an annual average of 900 million metric tons of carbon dioxide into the air, the European Union says.

A 2010 EU directive requires vessels docked in European ports for more than 2 hours to reduce greenhouse gas emissions.

The shore-to-ship systems employ power transformers and frequency converters to adapt the onshore power frequency of 50 hertz to the 60 hertz used by most ships.

The diesel generators cause considerable noise and vibrations and emit noxious fumes. Because many seaports are in densely populated areas, this can cause clashes with nearby residents.

In New York, people living near the cruise ship terminal at Red Hook have long battled to have a shore-to-ship electricity system installed but it has been delayed by years of arguing over who would pay the $19 million in costs.

But the Port Authority of New York and New Jersey is set to approve the project after an agreement was reached between it, Carnival Cruise lines, Consolidated Edison and state and local governments, the New York Daily News reported.

The system will cut nearly 100 tons of nitrous oxide, 100 tons of sulfur oxide and more than 6 tons of particulate matter from the air each year, New York officials say.

While the Red Hook Cruise Terminal will be the first dock on the U.S. East Coast to adopt the clean technology, the Port of Los Angeles on the West Coast last year installed a shore power system, joining the ports of Juneau, Alaska; Seattle; Vancouver, British Columbia; San Francisco; and San Diego in that regard.