Air quality

The switch from onboard-generated electricity to OPS will benefit local air quality significantly, as local emissions will be all but eliminated. These emissions will be replaced by lower emissions more remote from residential areas.

The following table reports the estimated reductions in local emissions calculated on the basis of the average EU-25 production mix.

Emission factors for auxiliary engines at berth, g/kWh of electricityNOXSO2PMVOC
Shoreside electricity (compared with 2.7% S Residual Oil (RO))-97%-96%-96%-94%
Shoreside electricity (compared with 0.1% S Marine Distillate (MD))-97%0-84%-94%

Source: Service contract on Ship Emissions: assignment, abatement and market based instruments, Task 2a shoreside electricity, Entec, 2005

Factors influencing the actual emission reduction
Although OPS will in most situations result in significant emission reductions, the precise percentage will vary depending on the emission factors of both the auxiliary engines and the remote power supply.

  • The reduction will be slightly influenced by the emission factors of the auxiliary engines or main generators, the type of fuel used (HFO/MGO) and the age of the engines on board. The younger the engine, the lower its emissions will be.
  • The actual emission reduction will also depend on the emission factors of the power plants feeding the local or national grid. Power sourced from wind turbines and hydropower plant causes no pollutant emission at all.

To assess the effects of OPS on pollutant emissions, the website provides an OPS calculation tool.