Now there is a new way, in the form of a dual-fuel diesel-electric system (DFDE), which has proven to be more efficient and easier on the environment due to lower fuel consumption and emissions.
The combination of dual-fuel engines, which can use boil-off gas from the carrier’s LNG tanks, and GE’s electrical variable-speed drives, presents a proven solution that is now commonly used on LNG carriers. The tanker’s DFDE drive systems are also more compact than traditional motor systems, enabling carriers to hold more cargo.
For each vessel, GE typically supplies two propulsion systems comprising of generators, main and cargo switchboards, transformers, MV7000 converters, motors and remote control.
GE Power Conversion marine business leader, Paul English, said the company had developed one of the world’s most reliable and cost-efficient power and propulsion solutions, combining induction-based technology with a pulse width modulation (PWM) converter.
“The combination of a single PWM drive and high-power direct drive induction motor per shaft line is both simple to install and operate, has a very low maintenance requirement and is extremely reliable,” Mr English said.
GE recently announced that six LNG carriers to be built by Hudong-Zhonghua Shipbuilding, part of the China State Shipping Corporation, would have power and propulsion systems supplied by the US company. The carriers will be used to aid the fast growing LNG export trade from Australia to China.