Abstract Diesel engines have proven themselves powerful, reliable and efficient. However, emissions from fuel combustion of diesel engine always leave by-products of oxides of nitrogen, unburned hydrocarbons and carbon monoxide in the exhaust gas. Therefore, environmentalists call for cleaner technology to be used in place of conventional diesel engine. The alternative option of diesel-electric engine is an applicable modern technology that generates lower air emissions. The diesel-electric engine for marine vessel offers significantly higher energy efficiency and lower air emissions, compared to the traditional diesel engine. Marine diesel-electric engine is a hybrid engine that uses diesel fuel to generate mechanical torque and transform to electrical power for driving motor and propels the ship. The developed electrical systems, where the diesel engine can be operated on a variable speed giving a huge potential in fuel saving. The Gensets operate in variable speed mode, where the rpm can be adjusted for minimum fuel oil consumption according to the system load. It also allows the integration of energy storage sources like batteries. The energy storage sources reduce the transient loads on the diesel engines. A petroleum company has therefore launched a green logistics program and adopt diesel-electric engine into the marine logistic process to be an initiative of the environmental friendly offshore operation. The Anchor Handling Tug Supply (AHTS) operate in the Gulf of Thailand for supporting offshore petroleum production. Since 2012, more than 50% of AHTS operated by diesel engines have been replaced by diesel-electric engines. By implementation of the green logistics program, in 2013 our marine fleet can decreased up to 7,100 m3 of Marine Gas Oil (MGO) consumption, whilst also reduces totally 22,000 tons of CO2e emission. Divided from overall picture, the replacement power driven of AHTS by diesel-electric engines contributed to the fuel saving at 4,000 m3 of MGO or 56 % of total MGO reduction. In economical perspective, a company has an opportunity to cut off fuel expense for 206 MMTHB or 6.9 MMUSD per annual. This could reflect a company determination to stay at forefront of the industry as the leading petroleum exploration and production company driven by green practices throughout our operation and supply chains.