LR has awarded Approval in Principle (AiP) to Empresa Naviera Elcano for their patented steam-to-hybrid conversion design for the transformation of steam turbine LNG carriers to a dual-fuelled propulsion system.
The transformation consists of a modification to the propulsion and electrical power generation system, upgrading the vessel from steam powered 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. The hybrid system also 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.
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.
Elcano’s solution will ensure the steam turbine LNG fleet will meet EEXI MARPOL regulations by substantially reducing greenhouse gas (GHG) emissions on converted vessels, prioritising both energy security and climate alignment for the maritime industry. Emission reduction and energy savings will increase dramatically if a vessels conversion includes the retrofitting of a reliquefication plant driven by a dual fuel generator. This will increase efficiency by minimising the vessels use of a steam dump system.
LR awarded this AiP following extensive testing assessment of the conversion design. The assessments found the available shaft power is 27% greater compared to the limited power for the vessel without the hybrid system and that the propulsion and electrical power are produced more efficiently, resulting in a substantial reduction in GHG emissions.