Towards a marine green power system architecture: Integrating hydrogen and ammonia as zero-carbon fuels for sustainable shipping

A broad consensus has been formed around global greenhouse gas emission reduction, and the task of realizing carbon reduction and decarbonization in the shipping industry is getting increasingly severe. Low-carbon and zero-carbon fuel power is the most direct and effective way to reduce ship emissions. However, it is difficult to form a mature power system configuration in designing, constructing, and applying low-carbon and zero-carbon fuel-powered ships due to the constraints of waters, routes, ship types, demand, power, alternative fuels, carbon emission reduction policies, and other dimensions. Based on this situation, to fill in the top-level architecture of the ship green power system and form a preliminary ship green power system configuration, this paper constructs a "demand-configuration-integration-system evaluation" architecture of ship green power system based on zerocarbon fuels from two kinds of zero-carbon fuels, i.e., hydrogen and ammonia. First, the demand for green ship power systems is sorted out, and the five ship system configuration elements, namely, fuel, power module, propulsion mode, aftertreatment mode, and propulsion module, are summarized. Then, the systems are combined and integrated, and the steps of the assessment of zero-carbon ship power systems are summarized by taking three typical power system configurations, namely, internal-combustion engine, fuel cell, and hybrid power systems, as examples. The green zero-carbon power system architecture proposed in this paper not only includes three kinds of inland near-sea and oceanic water requirements but also involves different ship types, such as container ships, bulk carriers, cruise ships, offshore engineering vessels, which can provide specific ideas and references for the designers/owners when designing and selecting a new type of zero-carbon powered ship.