Page 24 - 2021 - Q3 - Minerva in Focus

GHG EMISSIONS: NEW REQUIREMENTS FOR SHIPPING

Engine Power Lately, there has been growing concern about climate change and global warming
and the way they both affect our daily routines. Regulators are making great efforts
Limitation (EPL) to force the various industry sectors towards more energy-efficient management
that will significantly impact CO 2 emissions.
A cost‑effective With regards to CO 2 emissions regulators had, until now, focused on the land and air
industries, but recently, there has been an initiative to include the marine industry in
solution to reduce carbon-reducing measures.
The easiest, most cost-effective solution to reduce a vessel’s GHG emissions is slow
a vessel’s GHG steaming, even though this also reduces the vessel’s operational availability. Achieving
this requires the vessel’s main engines to derate in a simple and efficient way the regu-
lating bodies can control and monitor.
emissions In the recent past, at the initial design stage of newbuildings, shipbuilders would over-
power vessels based on a potential high-speed operational profile against high seas
without considering their GHG emissions. As a result, most vessels sail with an excess
reserve power that is seldom used.
The minimum installed power on each type and size of vessel, which is the minimum
power that class would accept to safeguard the vessel’s maneuverability when loaded
and in adverse weather conditions, is regulated by IMO MEPC.1/Circ.850/Rev.2. Depend-
ing on the shipbuilder, a vessel’s operating speed and installed power may be marginal-
ly or substantially higher than the required minimum propulsion power.
Considering the above, makers have introduced the Engine Power Limitation (EPL)
function, allowing the vessel to be officially derated and, consequently, to have a lower
operational speed.
Current EPL rules and regulations require that the EPL limiter should be overridable
in an emergency, and specific instructions should be available on board. In addition,
vessels must be provided with an EPL management plan in which all the deactivations
of the limiter function must be officially logged.
The limitation of the engine power is essentially achieved by installing a limiter in the
main fuel pumps so that they do not supply the fuel injectors of the main engine to their
full capacity. Depending on the engine type, there are two ways to achieve this:
• Mechanically controlled engines: A mechanical fuel limiter that limits the me-
chanical actuator of the governor in conjunction with a change in settings in the
M/E governor control system.
• Electronically controlled engines: Fuel limitation is effected using engine-control
software to change the M/E governor control system settings.
by Kostas D. Papadodimas It should be noted that the EPL application guidelines are currently under re-consid-
Technical Manager, eration and are expected to be revised soon to better address the issue of the reserve
Minerva Marine Inc. power activation in an emergency case.

22 MINERVA IN FOCUS – ISSUE 17 / Q3 2021