## 3 Analysis of the Previous Prediction
### Propulsion Solutions on LNG Ships Comparison
The DFDE drive, which is considered one of the first alternatives to steam turbine systems, was introduced in 2006. This system can run on both diesel and boil-off gas and uses two different operating modes to drive the main generators: gas and diesel operation. The generators then drive electric motors, which improves the overall efficiency by over 20% compared to conventional steam turbine drive systems. The introduction of TFDE propulsion systems in 2008 represented a significant innovation in LNG ship technology. These vessels offered a significant improvement in adaptability as they could utilize HFO as an additional fuel source. Compared to conventional steam turbine propulsion systems, which can adapt to different fuel types depending on sailing conditions, TFDE ships offer an improvement in overall efficiency of up to 30% [36]. In 2022, a new propulsion type was added to the drive types. The MAN B&W ME-GA is based on the proven MAN B&W dual-fuel concept with negligible installation effort and has an efficient ignition concept and an irreplaceable gas supply system that ensures safe and reliable operation [37]. In addition, the ME-GA is characterized by nominal operating costs, simple supply and treatment concepts, and low maintenance costs for the fuel gas supply system. Itcomplements the established MEGI diesel engine in MAN Energy Solutions' two-stroke engine portfolio, which now offers low-pressure and high-pressure dual-fuel solutions for LNG operation [38]. The ME-GA engine is a low-pressure, Otto cycle, two-stroke, dual-fuel LNG engine developed primarily for the LNG carrier market. It is designed to offer ship owners a lower capital cost option that can compete with WinGD's XDF engine. The launch of the ME-GA engine in April 2021 was a complete success: 100 orders were placed in the first eight months. To date, more than 260 units have been ordered, of which more than 40 are already in operation. Each ME-GA engine features exhaust gas reduction technology (EGR), which reduces methane slip emissions by up to 50% compared to first-generation Otto cycle engines without EGR. This technology not only helps to reduce emissions but also improves fuel efficiency in both gas and oil operations, which supports compliance with Tier II and Tier III standards. It quickly took the top position on the order lists for ships, only for these engines to stop being sold in 2024 due to new circumstances. The focus here is on methane slip, i.e., unburned methane (CH4) that escapes into the atmosphere during combustion. Methane is a particularly worrying greenhouse gas because, according to the US Environmental Protection Agency [39], it traps heat 28 times more effectively than carbon dioxide (CO\({}_{2}\)) over a 100-year period. The International Maritime Organization (IMO) is therefore developing regulations to control methane emissions in international shipping, which are to be implemented by 2027. At the same time, the European Union is taking measures with its FuelEU Maritime Policy, which should lead to the regulation of methane emissions from 2025 [40]. For the Danish engine manufacturer, which has invested hundreds of millions of euros in the development of low-carbon and carbon-free engine technologies for the maritime industry, this change in regulations is a major challenge. Although the exact amount of investment in the ME-GA engine has not been disclosed, it is clear that significant funds will need to be deployed to meet the growing demand for cleaner marine engines [41]. Therefore, the new IMO regulations on methane slip, which are expected to come into force in 2027, would require significant technical updates and investment, making this engine no longer economically viable [42]. Figure 5 shows a forecast for the share of the propulsion market for the period between 2019 and 2025. Although it is difficult to predict future trends with certainty, the current market focus is clearly shifting from steam turbines to more fuel-efficient LNG engines.