NCPA - National Center for Policy Analysis


June 29, 2004

To curb high diesel emissions from docked cargo ships, ports around the world are installing electrical outlets, allowing vessels to shut off their diesel-run auxiliary engines. Electric cables can now power on-board operations like refrigeration, lighting, climate control and machinery.

Pollution in ports often spreads to the communities nearby:

  • A docked cargo ship can burn seven tons of diesel fuel a day to run its electrical generators.
  • Ships docked at the Los Angeles and Long Beach ports emit 13.4 tons of nitrogen oxide per day, equal to 500,000 cars and trucks.
  • Ports along the lower Mississippi River, the New York metro area, and in south Texas also rank among those with the dirtiest air.
  • Surrounding communities and port workers often have higher rates of respiratory infections and a higher risk of cancer.

Substituting electricity for diesel can be expensive, though. In Juneau, Alaska, industry experts estimate that Carnival Corp.'s Princess Cruises company spends up to $5,000 per day per ship for electricity, compared to the $3,500 a diesel generator would cost.

Using electricity at ports -- also called "cold ironing" -- faces several challenges in becoming the industry standard, say observers: A lack of U.S. and international emissions regulations, cost-effectiveness issues, and questions of who should pay to outfit ports with electrical gear.

Source: Peter Sanders, "Plug-In Ships Could Reduce Port Pollution," Wall Street Journal, June 25, 2004.

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