The main subject of research involves the characteristics and assessment of the already ongoing process of maritime shipping radical decarbonization. There were identified and analyzed international legal and administrative regulatory measures as well as a package of technical, technological, operational and economic solutions, including the possibility of choosing alternative low-emission fuels that are necessary to achieve the already set targets by 2050. This research aimed to indicate and assess the most promising types of measure which are to be applied to achieve the required reduction of CO2 emissions in global shipping as well as developing a potential roadmap leading to their implementation. In the conducted research work, mainly qualitative analyses were applied, i.e., factor analysis (FA), comparative analysis (CA), and a series of consultations with representatives of the maritime industry were carried out, following the procedure typical for the Delphi technique. The main result of the research work is the development of a scenario for potential supply and distribution of fuels to the maritime shipping market by 2050. The basic conclusion is that shortages in manufacturing, commercialization, and supply of low and zero-emission fuels to the shipping market may be the main obstacle hampering the reaching of the targets of shipping industry decarbonization. Such a scenario could significantly slow down the stepping up process of greening the global supply chains.

The paper presents a probe of LNG usage analysis as a marine fuel. The restrictions of harmful substances emission to atmosphere from marine engines, especially in controlled emission areas (ECA and SECA areas) of nitrogen oxides and sulfur oxides, forces the engine makers to use additional installations, which operation may fulfill the cleanness requirements of exhaust gases. The option is a usage such marine fuels which fulfill the requirements without any cleaning processes. Such fuels are gaseous fuels, especially liquid natural gas (LNG) or compressed natural gas (CNG). It was undertaken many tests for determination the conditions of safety bunkering, storage on board, preparation and supplying the fuel to the engine and realization of working process. About dozens merchant ships were applied LNG as a fuel. There is enough experience for spreading the LNG usage. The basic problem is still the limited network of LNG distribution in ports. The next one is the conviction of shipowners that is no return from transition to the LNG or CNG fuelling. In the end it may occurred to the double beneficial situation that the fuel costs would be decreasing and simultaneously the improvement of exhaust gases quality (the restriction of negative effects for the natural environment).

The goal of reducing the climate impact of shipping requires many different activities. To reduce greenhouse gas emissions, the International Maritime Organization prepared some proposals to meet and fulfill the requirements. It sets out the provisions of the International Convention for the Prevention of Pollution from Ships 73/78 Annex 6—Prevention of the Air Pollution from Ships (1997) with the amendments and the future objectives set. The main objective is to achieve climate neutrality from shipping by 2050. One method is the decarbonization of marine fuels. The types of fuels that are transient fuels, with the final target fuel being hydrogen, are shown. Carbon dioxide emissions depend on the chemical composition of the fuel, its Lower Heating Value and the engine efficiency. The aim of the manuscript is to demonstrate that the use of fuels with lower carbon content is a transitional process enabling the hydrogen era to take place. An analysis of this problem is presented as a review of the subject along with the author’s comments and observations. The development of technologies for adapting potential fuels to combustion requirements in marine diesel engines and gas turbines, together with their storage and bunkering capabilities, are the main barriers to their limited use. The efficiency of marine diesel engines reaches a value of about 50%, while that of fuel cells are close to 100%. It seems that hydrogen will be the fuel of the future, including in shipping. Its basic use is in fuel cells, the efficiency of which is almost twice that of current thermal internal combustion engines.

Ship propulsion configurations with dynamic positioning systems are commonly used as diesel-electric. In particular, situations for ship transfer on longer distances may be used conventional mechanical propulsion system with controllable pitch propeller. Combination of mechanical and electric propulsion system called hybrid propulsion is met as well, where the thrusters of DP systems are driven through the gear by mechanical engine or electric motor independent or both. For the sake of the necessity of limitation of total installed power on the ship may occurred problems with power distribution between the ship propulsion and industry part. It will especially concern those situations when we need to keep power supply to the industry part and there is a necessity to increase the power delivered to ship propulsion part for the purpose of keeping the ship position or heading. The primary task of power management system (PMS) is blackout prevention in ship energetic network and so power distribution to overcome critical conditions of it. Temporarily it may occur the worsening of positioning operation accuracy without any critical situations of industry part. The possibility of momentary overloading of energetic network is primary condition of safety. The critical duration of overloading is one minute. This is indispensable time for increasing the accessible power in the energetic system through switching on the next genset to work. It is a necessity of quick analysis in critical conditions to value what key-actions ought to do in the aim of overcoming emergency situations. The next one is a usage of energy storage devices. It is possible through AC/DC conversion. It was tried to find solutions of equalization the load of gensets to the ship electric energy demand.

Improving safety and reliability of ship propulsion system during dynamic positioning (DP) operations of multipurpose vessels is an essential advantage. It may be such possibilities obtained by application the considered solutions of propulsion systems and all other elements of energetic system. The minimum requirements were determined by creating the regulations of dynamic positioning systems and their levels. Applying the solutions, which were exceeded the limits of basic requirements, allows to increase the safety and reliability levels with a low rise the investment costs. Many marine companies try to invent so low cost solutions. An example analysed in the paper is the Wartsila LCC system. The applications of more complicated solutions in comparison to required duplicated systems are expensive. The cheaper solution is an investing in the development of automatics configurations (for those systems it was applied the triple and quadruple configurations) which in transient or emergency conditions may obtain the time delay making possible a support of industry part work and DP systems. In emergency situation, after the loss of position by DP system, the power management system allow the safe break of work the industry part and return to work after elimination the critical condition.