The maritime industry is addressing environmental issues, and “cold ironing” offers a promising solution. This method involves supplying ships at port with energy, reducing fossil fuel dependence and emissions, and aiding in global climate change efforts. It is especially important for islands like Lesvos, which suffer from high energy costs and environmental issues due to imported fossil fuel reliance. However, research gaps exist in using renewable energy sources (RES) for cold ironing, mainly due to insufficient data on power needs and lack of monitoring for precise calculations and the very limited applications for the case of non-interconnected islands. This study uses real data from the port of Lesvos to evaluate power requirements for cold ironing and assesses the viability of a wind power park for an electrified port with the novelty and uniqueness of developing the application on a non-interconnected island. It also examines potential CO₂ emission reductions. Data from Marine Traffic S.A. were used, considering factors like ship arrivals, hoteling duration, and engine types. This study also includes a simulation using RETScreen software for a 20 MW wind park intended for port operations. The findings show that the monthly energy demand at Mytilene port is around 6118 MWh, with an average power demand of 8.2 MW. The simulated wind park could supply about 72,080 MWh yearly, with a significant surplus (14,956 MWh annually) exportable to the grid. However, demand fluctuations mean the port might need an extra 924 MWh from the main grid. This underscores the need for additional strategies like energy storage and demand–response practices to fully transition to 100% RES-powered operations.

The maritime sector, grapples with environmental challenges, but the adoption of "cold ironing" emerges as a promising solution, signifying a shift toward sustainability by providing energy to ships at port, reducing reliance on fossil fuels, and significantly lowering emissions, contributing to global climate change efforts. This transition towards renewable energy is especially crucial for islands like Lesvos, addressing challenges of high energy costs and environmental degradation resulting from reliance on imported fossil fuels, highlighting the potential for positive economic and environmental impacts. The existing literature highlights a research gap in the development of Renewable Energy Sources (RES) to support cold ironing operations, specifically due to the absence of specific data for the power demand needed in such operations and the lack of monitoring data for accurate calculations. This study's primary objective is to utilize real monitoring data from the port of Lesvos to evaluate the power demand for a potential cold ironing application. Additionally, the study aims to analyze the implementation of a wind power park to meet the energy needs of an electric port and evaluate the potential reduction in CO2 emissions. The database of Marine Traffic S.A. was utilized, while the determination of the energy used in-port per ship depended on factors such as the number of arrivals, the duration of hoteling, and the type of engine used by the ships. In addition, the software RETSCREEN was used for the energy analysis of a simulated 20 MW wind park that can support the in-port operations. The combined monthly energy demand for both main and auxiliary engines of shipping vessels at Mytilini port was assessed to be 6118 MWh and averaging a power demand equaled to 8.2 MW. The simulation analysis indicates that the annual electricity delivered to the port can be72080 MWh, with a significant portion remaining unused and exported to the grid, amounting to 14956 MWh annually. Due to demand fluctuations, in-port activities require an additional 924 MWh from the main electrical grid, which highlights the importance of additional measures like energy storage and demand-response practices for the gradual transition to 100% Renewable Energy Sources (RES) operations.

Gavdos is assessed as a non-interconnected island without mainland electricity exchange over the adopted planning horizon. A configuration with 340 kWp of photovoltaics, an 800 kW wind turbine, and surplus-fed electrolysis is evaluated for electricity supply and ferry hydrogen. Twelve public HEDNO monthly day-ahead files were concatenated into an 8760 h rolling-year demand series. RETScreen-based F-chart solar calculations and a Weibull wind distribution (k = 2) provided twelve representative monthly 24 h renewable profiles, mapped by month and hour to the dispatch chronology. Renewable generation first serves demand; deficits are assigned to conventional generation and surplus to electrolysis. Annual demand is 662.630 MWh, of which renewables supply 650.633 MWh directly (98.19%); the residual deficit is 11.997 MWh across 419 h. The 302.6 kW baseline electrolyzer produces 34.488 t H₂ year⁻¹ gross versus a ferry demand of 33.890 t H₂ year⁻¹. Although daily production is lower than demand in 130 days, accumulated hydrogen keeps the gross inventory non-negative. The maximum seasonal drawdown is 947.4 kg, giving a usable hydrogen-mass requirement of 1133.1 kg including a two-day reserve. The results demonstrate gross-production compatibility under the adopted assumptions; net ferry-fuel adequacy requires detailed assessment of component operation, auxiliary loads, storage, delivery, and vessel duty.