Abstract
Onshore power supply (OPS) is a key enabler for decarbonizing port operations and meeting upcoming regulatory targets such as the EU AFIR Regulation 2023/1805 and Portugal's PNEC 2030. This paper presents a simulation-based framework for estimating the OPS demand of container ships at berth, integrating ship hoteling loads, reefer thermal dynamics with flexible control, and OPS/auxiliary engine (AE) dispatch under port grid constraints. A case study at Terminal XXI of the Port of Sines demonstrates the approach using high-resolution (1-minute) simulations. Results show that reefer flexibility enables peak shaving, OPS demand can be enforced within available grid capacity without violating thermal limits, and AE provides reliable backup. Complementary machine learning modules based on Gradient Boosting, Random Forest, and XGBoost enable accurate imputation of missing ship descriptors and OPS demand forecasting (R2 > 0.95). The framework provides an AI-ready decision-support tool for OPS infrastructure planning and port energy management. © 2025 IEEE.

Abstract
The lack of open-source platforms capable of integrated operational modeling and multi-scenario decarbonization analysis, often hinders data-driven decision-making in the maritime sector. To address this gap, this paper presents an open-source, multi-agent, discrete-event simulator capable of accurately forecasting the energy consumption associated with the diverse assets and activities within a container terminal. The tool's modular architecture enables transparent evaluations of operational strategies and decarbonization alternatives by allowing users to systematically modify inputs or alter embedded energy modules. The tool's capabilities were validated through a case study of a medium-sized Portuguese container terminal. For this particular port, findings indicate that installing three onshore power supply (OPS) units and fully electrifying the internal truck fleet yields the most substantial emission reductions. However, these interventions result in a two-fold increase in daily electricity demand, potentially straining grid capacity. This finding underscores that the effectiveness of terminal electrification as a decarbonization strategy ultimately depends on a simultaneous transition to a decarbonized and secure energy supply.