Fuel and CO₂ savings when a ship plugs into Onshore Power Supply (OPS) instead of running auxiliary engines at berth.
Formula
$$ F_\text{avoided} = \frac{P_\text{load} \cdot h \cdot \text{SFOC}}{10^6} $$
$$ \Delta \text{CO}2 = F\text{avoided} \cdot C_f - \frac{P_\text{load} \cdot h \cdot \text{EF}_\text{grid}}{10^6} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $F_\text{avoided}$ | Auxiliary fuel displaced by shore power | t | result |
| $P_\text{load}$ | Average hotel + cargo electrical load | kW | electrical load analysis |
| $h$ | Hours alongside on shore power | h | port-call log |
| $\text{SFOC}$ | Aux engine SFOC at port load | g / kWh | NOx Technical File |
| $C_f$ | CO₂ factor of displaced aux fuel | t CO₂ / t fuel | MEPC.364(79) |
| $\text{EF}_\text{grid}$ | Shore-grid CO₂ emission factor - EU 2023 ≈ 250, Norway < 30, coal-heavy > 700 | g CO₂ / kWh | national grid inventory |
| $\Delta \text{CO}_2$ | Net CO₂ saving (ship side minus shore side) | t | result |
Local pollutant benefit (SOx, NOx, PM) is 100 % at the berth regardless of grid carbon intensity - that is usually the regulatory driver (CARB At-Berth, EU AFIR, FuelEU port stays).
Sources
- IEC 80005-1 - High-voltage shore connection.
- EU AFIR (EU) 2023/1804 - alternative fuels infrastructure.