Shaft-Generator / PTO Credit

Electric power produced from the main-engine shaft (PTO mode) instead of a running aux engine. Recognised EEDI Category-B credit under MEPC.1/Circ.815 and a common FuelEU saving.

DesignPTO

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

F_\text{saved} = \frac{P_\text{PTO} \cdot h \cdot \text{SFOC}_\text{AE}}{10^6}

Symbol	Meaning	Unit
$P_\text{PTO}$	Electrical output produced by the shaft generator	kW
$h$	PTO running hours	h
$\text{SFOC}_\text{AE}$	SFOC of the aux engine that would otherwise run	g / kWh
$\text{SFOC}_\text{ME}$	SFOC of the main engine supplying the PTO	g / kWh
$F_\text{saved}$	Aux fuel displaced	t
$F_\text{extra}$	Extra ME fuel burned to cover the PTO load	t
$C_{f,\text{AE}}, C_{f,\text{ME}}$	CO₂ factors for the aux and ME fuels	t CO₂ / t fuel

Source: IMO MEPC.1/Circ.815 - innovative energy-efficient technologies; MAN Energy Solutions - *Shaft Generator Packages*

In short

Fuel and CO₂ impact of running a shaft-generator (PTO) instead of an auxiliary engine.

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