可再生能源航运选择（英文版）_60页-2mb

Summary of Renewable Energy Options for Shipping

Core Content

This document outlines the current status, applications, and potential of renewable energy in the shipping industry. It highlights the importance of shipping in global trade and its role in supporting island communities. The transition to renewable energy is seen as a critical step in reducing greenhouse gas emissions and improving energy efficiency, despite existing challenges.

Main Points

• Role of Shipping:
  The shipping industry is vital for global trade, transporting around 90% of all traded goods. Global shipping tonnage has increased significantly since 1970, and demand is expected to grow further due to economic development and supply chain complexities.

• Current Energy Sources:
  Ships have historically used fossil fuels like coal, HFO, and MDO. These fuels contribute to approximately 2.8% of global greenhouse gas emissions. Although shipping has low CO₂ emissions per tonne-kilometre, emissions are expected to rise with increased demand.

• Renewable Energy Options:
  Renewable energy technologies such as wind, solar, biofuels, wave energy, and hydrogen fuel cells are being explored for use in ships. These include:

  • Wind: Soft sails, fixed wings, rotors, kites, and wind turbines.
  • Solar: Used mainly in hybrid models for small ships.
  • Biofuels: Including first, second, and third generation biofuels.
  • Wave and Hydrogen: Emerging technologies with potential but limited current applications.

• Integration of Renewable Energy:
  Renewable solutions can be integrated through retrofitting existing ships or through new ship designs. Some new ships are aiming for 100% renewable energy or zero-emission technologies for primary propulsion.

Key Renewable Technologies and Applications

Wind Energy

• Soft Sails: Used in small to medium ships (e.g., Greenheart, B9, Ecoliner).
• Fixed Wings: Implemented on some vessels, with potential for larger ships.
• Rotors (Flettner Rotor): Demonstrated in ships like Alcyone and E-Ship 1.
• Kites: Applied in MS Beluga Skysails.
• Turbines: Still in development with no successful prototypes.

Solar Photovoltaics

• Mainly used in auxiliary propulsion and ancillary power for small ships.
• Hybrid models are more common, with applications such as the NYK Auriga Leader and SolarSailor.

Biofuels

• First-generation biofuels are being used in some ships, while second and third-generation biofuels are under development.
• Advanced biofuels show high potential for transforming the sector but depend on sustainable feedstock availability.

Hydrogen Fuel Cells

• Used in small ferries and river boats, such as the FCS Alsterwasser.
• The Flettner rotor was successfully tested on the Viking Lady in 2012, achieving 44.5% efficiency.
• Challenges include hydrogen production sustainability and storage reliability.

Wave Energy

• Limited to new builds, with potential for both main and auxiliary propulsion.

Barriers to Adoption

• Organisational/Structural: Limited R&D funding and lack of reliable cost data.
• Behavioural: Concerns from ship owners over additional costs and opportunity costs.
• Market: Split incentives between ship owners and operators, reducing investment motivation.
• Non-Market: Infrastructure lock-in and lack of public awareness or pressure.

Opportunities and Recommendations

• Quick-Win Solutions: Focus on small ships, which are more numerous and have higher emissions per unit of cargo.
• Integrated Systems: Renewable energy should be part of an overall efficiency strategy, combining with other technologies.
• Policy Support: Governments should promote R&D, innovation, and proof-of-concept projects to support commercial viability.
• Collaboration: International cooperation and strategic partnerships are essential for advancing renewable energy in shipping.

Conclusion

The adoption of renewable energy in shipping is still in its early stages, but it holds promise for reducing emissions and improving energy efficiency. The transition requires overcoming both market and non-market barriers, along with supportive policies and continued innovation. While the potential for renewables to dominate the sector is limited in the near future, they can make a significant contribution in specific applications, especially when integrated with other energy efficiency measures.