Posted: January 24th, 2024
Research on the application of solar photovoltaic system on large ocean-going ships
Research on the application of solar photovoltaic system on large ocean-going ships
Solar photovoltaic (PV) technology is a promising way to reduce the carbon footprint and fuel consumption of the shipping industry, which relies heavily on fossil fuels. However, applying solar PV systems on large ocean-going ships poses several technical challenges, such as integrating PV equipment into the ship power system (SPS) without changing its original structure, managing the intermittent and variable nature of solar power, and ensuring the reliability and safety of the PV system in harsh marine environments. This paper reviews the current state of the art and future prospects of solar PV systems for ocean-going ships, focusing on the design principles, operation modes, performance evaluation, and economic feasibility of such systems.
The paper first compares the existing technical differences between off-grid and grid-connected PV systems for marine applications, and proposes some basic design principles for integrating PV equipment into the SPS. Off-grid PV systems operate independently from the SPS and supply power to specific loads, such as lighting or auxiliary equipment. Grid-connected PV systems are connected to the SPS through an inverter and can supply power to any load on the ship. The paper discusses the advantages and disadvantages of each mode, and suggests that a hybrid PV system that can switch between off-grid and grid-connected modes according to the solar radiation resource, power load requirement, and state of charge (SOC) of the battery storage device is a more flexible and efficient solution.
The paper then presents a case study of a hybrid PV system installed on a 5000 PCTC ro-ro ship as an independent subsystem. The system consists of 300 kWp of PV modules, 200 kWh of lithium battery storage, and a bidirectional inverter. The system can operate in three modes: off-grid mode, grid-connected mode, and islanding mode. In off-grid mode, the system supplies power to a dedicated load group that includes lighting, ventilation, refrigeration, and communication equipment. In grid-connected mode, the system injects power into the SPS and reduces the fuel consumption of the diesel generators. In islanding mode, the system disconnects from the SPS and operates as an emergency power source in case of a blackout. The paper describes the operation logic and control strategy of the system, and reports the test results that show its stable operation characteristics under different modes.
The paper also evaluates the performance and economic feasibility of the hybrid PV system based on experimental data and simulation results. The paper uses a mathematical model to estimate the annual energy production, fuel saving, CO2 emission reduction, and payback period of the system under different scenarios. The paper considers various factors that affect the performance of the system, such as solar radiation intensity, ship speed, ship heading, shading effect, tilt angle, temperature effect, degradation rate, and maintenance cost. The paper concludes that the hybrid PV system can achieve significant environmental and economic benefits for ocean-going ships, especially for those operating in tropical or subtropical regions with high solar radiation.
The paper finally discusses some future research directions and challenges for solar PV systems on ocean-going ships. The paper identifies some key issues that need further investigation, such as optimizing the configuration and layout of PV modules on ship decks, developing advanced control algorithms and power management strategies for hybrid PV systems, improving the reliability and safety of PV equipment under marine conditions, integrating PV systems with other renewable energy sources or energy storage technologies on ships, and assessing the life cycle impact and social acceptance of solar ships.
References:
Sun Y., Yan X., Yuan C., Tang X., Malekian R., Guo C., Li Z. (2019). The application of hybrid photovoltaic system on the ocean-going ship: engineering practice and experimental research. Journal of Marine Engineering & Technology 18(1): 56-66.
Plugboats (2022). Cargo ship with solar panels could help cut use of world’s dirtiest fuels. Retrieved from https://plugboats.com/sails-with-solar-panels-could-help-cut-cargo-ship-use-of-the-worlds-dirtiest-fuels/
Nature (2022). Could the oceans host floating solar power plants? Retrieved from https://www.nature.com/articles/d41586-022-01893-8