Spanish shipping firm Empresa Naviera Elcano has won an approval in principle from classification society LR for its steam-to-hybrid conversion design which will allow shipowners to convert steam-powered LNG carriers to hybrid dual-fueled propulsion.
According to a statement by LR, the transformation consists of a modification to the propulsion and electrical power generation system, upgrading the vessel from steam propulsion to a hybrid system with a steam turbine and dual-fuel generator.
The dual-fuel generator will supply electrical power to the ship’s switchboard with electric propulsion motor/s coupled to the ship’s propulsion gear box/shaft.
Also, the hybrid system includes devices that can recover energy from the dual-fuel generator exhaust gases and engine cooling systems, which will be integrated into the existing steam plant systems.
Conversion could benefit the one-in-three steam LNG carriers
The conversion could benefit the one-in-three LNG carriers that rely on steam propulsion and are currently at risk of being non-compliant with the IMO’s EEXI and CII regulations, without the need to scrap any part of the original steam propulsion system, LR said.
Elcano’s solution would ensure the steam turbine LNG fleet would meet EEXI MARPOL regulations by “substantially” reducing greenhouse gas (GHG) emissions on converted vessels, it said.
Moreover, emission reduction and energy savings would increase “dramatically” if a vessels conversion includes the retrofitting of a reliquefication plant driven by a dual-fuel generator, LR said.
This would increase efficiency by minimizing the vessels use of a steam dump system, it said.
LR said it awarded this AiP following “extensive” testing assessment of the conversion design.
The classification society said the the assessments found the available shaft power increases 27 percent compared to the limited power for the vessel without the hybrid system, while the system also allows “more efficient” propulsion and electrical power production.
This results in a “substantial” reduction in GHG emissions, LR said.