Independent Innovation in Energy-Efficient Ship Propellers: The Driving Force Behind Green Shipping

Introduction

Against the backdrop of the global shipping industry's accelerated transition toward green and low-carbon development, improving vessel energy efficiency and reducing emissions have become central priorities for the maritime sector. According to the International Maritime Organization (IMO), the shipping industry emits more than one billion tonnes of carbon dioxide (CO₂) each year, accounting for approximately 3% of global anthropogenic greenhouse gas emissions. Without effective mitigation measures, emissions from international shipping could increase several-fold by 2050.

During vessel operation, more than half of the energy consumed is used to drive the propeller and generate thrust. Consequently, the independent research, development, and innovation of energy-efficient ship propellers can not only directly reduce operating costs for shipping companies but also play a strategic role in promoting the maritime industry's low-carbon transition and supporting national carbon peaking and carbon neutrality goals. In recent years, Chinese research institutions and innovation teams have made continuous advances in the field of energy-efficient ship propellers. Through innovations ranging from structural optimization to advanced materials development, they have achieved a series of technologies with independent intellectual property rights, contributing Chinese solutions to the global development of green shipping.

1. Maritime Decarbonization Is Driving the Upgrading of Energy-Efficient Propeller Technologies

In recent years, international regulations on greenhouse gas emissions from shipping have become increasingly stringent, imposing mandatory requirements on vessel energy efficiency. Since 2023, the International Maritime Organization (IMO) has officially implemented the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII), requiring existing vessels worldwide to meet minimum energy-efficiency standards. Ships that fail to comply face operational restrictions and an increased risk of being phased out of the market.

For shipping companies, this means either upgrading existing vessels or facing declining competitiveness. As the core component of a ship's propulsion system, the propeller plays a decisive role in determining overall fuel consumption and carbon emissions. Consequently, innovation in energy-efficient propeller technology has become an urgent necessity for the industry.

Conventional ship propeller design has traditionally focused on maximizing thrust and ensuring structural strength, while giving relatively limited consideration to energy-saving performance. As vessels age, propeller surfaces are increasingly affected by corrosion and marine biofouling, both of which increase hydrodynamic resistance and reduce propulsion efficiency. Studies indicate that after approximately five years of operation, biofouling on conventional propellers can reduce propulsion efficiency by more than 10% and increase fuel consumption by over 8%.

Moreover, during operation, conventional propellers tend to generate low-pressure vortex regions on the suction side of the blades, resulting in significant form drag. This not only limits vessel speed but also leads to considerable energy loss. The growing demand for high-efficiency, energy-saving propellers has therefore created broad opportunities and strong momentum for Chinese research teams to pursue independent technological innovation.

As the world's largest shipbuilding nation and a major maritime power, China possesses a comprehensive shipbuilding industrial chain. Mastering the core technologies of energy-efficient ship propellers is therefore crucial for safeguarding the security and resilience of the country's maritime industrial and supply chains. In the past, the design and manufacturing technologies for advanced energy-saving propellers were largely monopolized by foreign companies, forcing Chinese shipbuilders to pay substantial patent licensing fees.

Promoting independent innovation in energy-efficient ship propellers and achieving self-reliance in core technologies will not only reduce shipbuilding costs but also enhance the overall competitiveness of China's shipbuilding industry. More importantly, it will strengthen China's position in the global green shipbuilding value chain and support its long-term objective of becoming a leading maritime manufacturing power.