Shipping plays a crucial role in global trade but remains one of the largest contributors to greenhouse gas emissions within the transport sector. With increasingly stringent international and regional regulations, the maritime industry is under growing pressure to adopt cleaner and more energy-efficient technologies. This thesis investigates the potential of Wind Assisted Propulsion Systems (WAPS), with a particular focus on Flettner rotor technology, to improve the environmental and economic performance of commercial vessels. Drawing on a comprehensive literature review, regulatory framework analysis, and a detailed case study of a bulk carrier, the research demonstrates that WAPS can enhance vessel efficiency, reduce fuel consumption, and contribute to compliance with key regulatory measures such as the EEXI, CII, EU ETS, and FuelEU Maritime initiatives. The findings underline the potential of WAPS as a viable decarbonization pathway but also highlight challenges related to system integration, operational performance, and cost-effectiveness. More specifically, the case study showed that while the Flettner rotor improved energy efficiency and reduced fuel use and CO2 emissions, it was insufficient for full compliance with environmental indicators. Further investigation is therefore needed into WAPS performance and the potential of hybrid energy efficiency technologies to achieve regulatory compliance.