In this blog post, we’ll explore why green ships are gaining attention, changes in international environmental regulations, and the direction of the latest green ship technologies, including LNG, methanol, and ammonia-powered vessels.
Tightening Environmental Regulations and the Emergence of Green Ships
As climate change and carbon neutrality have recently emerged as global challenges, the shipping industry is also undergoing significant changes. Whereas a ship’s cargo capacity and operating speed were once the key factors in competitiveness, the amount of fuel consumed and the levels of greenhouse gas and air pollutant emissions have now become critical evaluation criteria.
Major air pollutants emitted by ships include carbon dioxide (CO₂), nitrogen oxides (NOx), and sulfur oxides (SOx). Carbon dioxide is a primary greenhouse gas that accelerates global warming, while nitrogen oxides and sulfur oxides are known to cause fine particulate matter and acid rain. In particular, because ships consume large amounts of fuel, their pollutant emissions are significant, making them a key target of international regulation.
To address these issues, the International Maritime Organization (IMO) has implemented various regulations to continuously manage ships’ energy efficiency and carbon emissions. The existing Energy Efficiency Design Index (EEDI) serves as a standard for improving the energy efficiency of new ships, and currently, the Energy Efficiency Existing Ship Index (EEXI)—which applies to existing ships—and the Carbon Intensity Indicator (CII)—which evaluates carbon emission efficiency during operation—are also in effect. Furthermore, the IMO is pursuing a phased reduction strategy aimed at achieving net-zero greenhouse gas emissions in international shipping by around 2050, and accordingly, the global shipbuilding industry is also actively engaging in the development of eco-friendly ships.
Ships developed to enhance energy efficiency and minimize pollutant emissions from the design stage onward, in response to these increasingly stringent environmental regulations, are generally referred to as “green ships” or eco-friendly ships.
Core Technologies for Building Eco-Friendly Ships
To build eco-friendly ships, it is not enough to simply switch fuels; a variety of technologies must be applied in conjunction. The most significant change is the transition to new propulsion fuels.
For a long time, ships have relied primarily on heavy fuel oil and diesel as their main fuels. However, these fuels have been identified as major sources of environmental pollution because they emit large amounts of sulfur oxides and nitrogen oxides. Consequently, the number of ships using LNG (liquefied natural gas) has been growing rapidly in recent years. LNG is considered an eco-friendly fuel because it emits almost no sulfur oxides and relatively less carbon dioxide than conventional heavy fuel oil.
However, some point out that since LNG is also a fossil fuel, it is not the ultimate solution. Consequently, active development is underway for next-generation eco-friendly ships that utilize methanol, ammonia, and hydrogen. In particular, ammonia and hydrogen are gaining attention as next-generation fuels capable of significantly reducing carbon dioxide emissions during operation, and they are regarded as core fuels for the future shipping industry, as their carbon reduction effects can be further enhanced depending on the production methods of these eco-friendly fuels.
Technologies that improve energy efficiency are also crucial. This is because a ship becomes more environmentally friendly if it can travel a greater distance using the same amount of fuel. To achieve this, technologies that minimize hull resistance are being applied during the ship design phase, and research to improve propeller propulsion efficiency is ongoing.
Recently, technologies such as the Air Lubrication System—which creates an air layer beneath the hull to reduce frictional resistance—the Waste Heat Recovery System (WHRS), which recovers waste heat from engines to generate electricity, and AI-powered optimal route navigation technology have been implemented on actual vessels. Additionally, some ships are utilizing a combination of solar panels and wind-assisted propulsion systems to reduce fuel consumption and improve energy efficiency.
The Significance of STX’s GD ECO-ship
Efforts to develop eco-friendly ships have also been ongoing in South Korea. One of the most notable examples is the GD (Green Dream Project) ECO-ship, unveiled by STX Offshore & Shipbuilding in 2009.
At the time, the GD ECO-ship garnered attention as a futuristic eco-friendly vessel capable of significantly reducing nitrogen oxide and sulfur oxide emissions, as well as cutting carbon dioxide emissions. Furthermore, by comprehensively applying various eco-friendly technologies—such as improved propeller efficiency, waste heat recovery systems, and the use of solar and wind power—it presented a concept that was quite advanced by the standards of the time.
Of course, from today’s perspective, the GD ECO-ship can be viewed as a transitional concept ship. At that time, even LNG-powered ships had not yet been widely adopted, and methanol, ammonia, and hydrogen-powered ships were mostly still in the research and demonstration phases. Nevertheless, the GD ECO-ship holds significant importance in that it widely publicized the concept of eco-friendly ships within the domestic shipbuilding industry and set the direction for the subsequent development of various eco-friendly ship technologies.
In fact, the Korean shipbuilding industry has since secured global competitiveness in the fields of LNG-powered vessels and LNG carriers, and recently, it has expanded its efforts to include the development of methanol- and ammonia-powered vessels, as well as next-generation hydrogen-powered vessels, thereby leading the eco-friendly ship market. Considering this trend, the GD ECO-ship can be regarded as one of the key milestones leading to the current advancements in eco-friendly ship technology.
The Korean Shipbuilding Industry in the Era of Eco-Friendly Ships
While Europe and Japan were once regarded as leaders in eco-friendly ship technology, the situation has changed significantly. The Korean shipbuilding industry has secured world-class competitiveness in the fields of LNG carriers and dual-fuel ships, and it also holds a leading position in the development of methanol- and ammonia-powered ships. Furthermore, research and development into future eco-friendly ship technologies—such as next-generation hydrogen-powered vessels, electric propulsion, and carbon capture and storage (CCS)—is actively underway.
In addition, with the full-scale development of smart ships integrating digital technology and artificial intelligence (AI), efforts to simultaneously ensure environmental sustainability and economic efficiency are continuing. With rapid advancements in AI-based operational optimization, fuel consumption analysis, predictive maintenance, and autonomous navigation technologies, the competitiveness of the shipbuilding industry is increasingly likely to be determined not simply by how many ships are built, but by the ability to develop ships that are efficient, eco-friendly, and digitally advanced.
Eco-friendly ships are no longer a technology of the distant future. Today, as international environmental regulations continue to tighten and carbon neutrality has become a global goal, eco-friendly ships are rapidly establishing themselves as the new standard in the shipping industry. In the future, next-generation ships that integrate eco-friendly fuels, digital technology, and autonomous navigation technology are likely to take center stage in the global market. Amid these changes, the Korean shipbuilding industry is expected to continue playing a vital role as a key leader in the future maritime industry, drawing on its accumulated technological capabilities and extensive shipbuilding experience.
