# Electrification in Maritime Vessels: Reviewing Storage Solutions and Long-Term Energy Management
## 1 Introduction  
### Rise of Electric Vessels and Their Power  
Traditional fossil-fuel-based marine propulsion systems significantly contribute to greenhouse gas emissions and environmental degradation, prompting increased scrutiny of the maritime industry. In response to global climate concerns, the International Maritime Organization (IMO) has implemented stricter emissions standards, aiming to reduce shipping-related emissions by at least 50% by 2050 compared to 2008 levels [1]. Another critical goal is to decrease the average CO\({}_{2}\) emissions per unit of transport work in international shipping by at least 40% by 2030, and 70% by 2050, relative to 2008 levels. These regulations promote lower sulfur fuel use, improved energy efficiency, and the adoptionof cleaner propulsion technologies like electricity, hydrogen, and ammonia. This shift is driving innovation and investment in sustainable maritime solutions, accelerating the industry's transition to a low-carbon future. Accordingly, countries around the world have begun to conduct comprehensive studies and invest in the development of electric marine vehicles as part of their broader strategies to combat climate change and promote sustainable transportation. These efforts include research into advanced battery technologies, energy storage systems, electric propulsion designs, and charging infrastructure tailored for maritime use. Norway's launch of its first fully electric ferry, the Ampere, in 2015 marked a pivotal step toward sustainable maritime transport. Building on this success, the country has rapidly expanded its electric ferry fleet, with 70 additional vessels demonstrating both environmental and economic viability. This momentum underscores Norway's strong commitment to cutting emissions and advancing green transportation, made possible by its plentiful renewable energy resources--especially hydropower--which power these ferries efficiently and cleanly [2]. The country is rapidly moving toward a future where the majority of its ferry fleet will be powered by battery-electric systems or hydrogen fuel. By 2030, most ferries in Norway are expected to operate with zero or near-zero emissions, further solidifying the nation's leadership in sustainable maritime transportation and demonstrating how policy can effectively support environmental goals [3]. In 2017, China launched the world's first fully electric cargo ship in Guangzhou, marking a significant milestone in sustainable maritime transport. Measuring 70 m in length, the vessel is capable of carrying up to 2000 tons of cargo and is powered by a 2.400 kWh battery system, giving it a range of approximately 80 km on a single charge [4]. Despite the irony that it primarily transports coal along the Pearl River, one of the busiest waterways in the world, the ship itself produces zero emissions during operation. This pioneering move highlights China's commitment to reducing carbon emissions in key industrial sectors [5]. By eliminating the use of fossil fuels in its propulsion system, the electric cargo ship reduces air and water pollution, contributing to cleaner urban environments. Moreover, it sets a precedent for the global shipping industry, encouraging further innovation in electric-powered vessels and signaling a shift toward more eco-friendly logistics solutions in the face of growing environmental challenges. Launched in 2019, the Ellen is one of the world's largest all-electric ferries and a groundbreaking example of sustainable marine transportation. Operating between the Danish islands of AEre and Fynshav, Ellen covers a distance of 22 nautical miles (approximately 40 km) on a single charge, making it ideal for regional routes [6]. Powered entirely by electricity, the ferry has eliminated the need for fossil fuels, resulting in a reduction of approximately 2000 tons of CO2 emissions annually.