Ehlers, SörenSörenEhlers2026-01-072026-01-072025-12-17Ships and Offshore Structures 21 (1): 20-22 (2026)https://hdl.handle.net/11420/60535Maritime transportation, although highly efficient, remains carbon-intensive and must undergo substantial transformation to achieve decarbonisation and ultimately emission-free operation by the 2050 regulatory target. Given the typical 25-year design life of ships, this transition requires both continuous retrofitting of the existing fleet and the integration of new technologies in newbuilds at varying levels of readiness. Currently, the feasibility of carbon- and emission-free solutions depends largely on the availability of alternative fuels, whose limited supply and demand result in high costs and price volatility. In parallel, optimisation of onboard energy systems remains crucial. Technologies, such as heat pumps, direct-current grids, wind-assisted propulsion and advanced route optimisation, provide practical pathways to improved efficiency and reduced emissions. This paper reviews these technologies and discusses the key challenges to achieving emission-free shipping.en1754-212X202512022Taylor and Francishttps://creativecommons.org/licenses/by-nc-nd/4.0/alternative fuelsDecarbonization of shippingenergy efficiency and retrofit solutionsgreen transformation in maritime transportsmart maritime technologiesSocial Sciences::388: TransportationSocial Sciences::333: Economics of Land and Energy::333.7: Natural Resources, Energy and EnvironmentJournal Articlehttps://doi.org/10.15480/882.1636910.1080/17445302.2025.260341410.15480/882.16369Journal Article