Analysis of Hybrid Ship Machinery System with Proton Exchange Membrane Fuel Cells and Battery Pack

Abstract

As marine traffic is contributing to pollution, and most vessels have predictable routes with repetitive load profiles, to reduce their impact on environment, hybrid systems with proton exchange membrane fuel cells (PEMFC-s) and battery pack are a promising replacement. For this purpose, the new approach takes into consideration an alternative to diesel propulsion with the additional benefit of carbon neutrality and increase of system efficiency. Additionally, in the developed numerical model, control of the PEMFC–battery hybrid energy system with balance of plant is incorporated with repowering existing vessels that have two diesel engines with 300 kWe. The goal of this paper is to develop a numerical model that analyzes and determines an equivalent hybrid ship propulsion system for a known traveling route. The developed numerical model consists of an interconnected system with the PEMFC stack and a battery pack as power sources. The numerical model was developed and optimized to meet the minimal required power demand for a successful route, which has variable loads and sees ships sail daily six times along the same route—in total 54 nautical miles. The results showed that the equivalent hybrid power system consists of a 300 kWe PEMFC stack and battery pack with 424 kWh battery and state of charge varying between 20 and 87%. To power this new hybrid power system, a hydrogen tank of 7200 L holding 284.7 kg at pressure of 700 bar is required, compared to previous system that consumed 1524 kg of diesel and generated 4886 kg of CO2.

Energy Management in a Super-Tanker Powered by Solar, Wind, Hydrogen and Boil-Off Gas for Saving CO2 Emissions

“…As mentioned above, our tanker is much bigger than the ships studied in [61,62]. A reliable comparison is made in Table 15 between Scenarios 1, 2 and 3 for the tanker with FCs and Scenario 4 for the tanker without FCs.…”

“…In study [62], to reduce the environmental impact, hybrid systems with fuel cells and battery packs are considered as an alternative to diesel propulsion ships. An equivalent vessel for voyages between the Croatian ports of Split and Resnik in the Adriatic Sea, in total 54 nautical miles, with a hybrid propulsion system with FC and battery and with a power system control, is being studied on existing vessels equipped with two diesel engines with 300 kW electric power.…”

Comparative Analysis of CO2 Emissions, Fuel Consumption, and Fuel Costs of Diesel and Hybrid Dredger Ship Engines

“…The development of energy-efficient engines is of utmost importance due to the reduction in pollutant emissions and the improvement of economic efficiency. New trends include the use of advanced fuel injection technology, the development of new materials to reduce engine mass, and the optimization of engine design [25]. In addition, the possibility of utilizing renewable energy sources to supplement the starting of marine diesel engines is being investigated.…”

“…Alternative propulsion systems for ships are innovative technologies and concepts that are used to power ships instead of conventional diesel engines. These systems include a variety of energy sources such as electricity, hydrogen, natural gas-based fuels, solar energy, and wind [25]. Electric propulsion systems are among the most widely used alternative systems and utilize batteries or fuel cells to power electric motors.…”

“…Hybrid engines are becoming increasingly popular as they have higher efficiency and lower CO 2 emissions compared to diesel engines and combine combustion with electric motors, which reduces fuel consumption and CO 2 emissions. When the ship is steered, the hybrid engine uses an electric motor for starting, and when a higher load or faster acceleration is required, an internal combustion engine is also used [25]. This combination makes hybrid engines more efficient under optimal driving conditions, which reduces overall CO 2 emissions.…”