Optimizing B2G Usage to Maximize Revenue and Ensure Warranty Compliance

Sammanfattning

With the development of maritime electrification, the Boat-to-Grid (B2G) systemshows great application potential. The battery is not only used for ship propulsion,but can also participate in grid services. However, B2G usage may accelerate batterydegradation. To solve this problem, this thesis builds an optimization modelto find the optimal daily usage strategy for boat batteries under B2G. The goal isto maximize profit while protecting battery lifetime. This study selects two typicalbattery types, Lithium Iron Phosphate (LFP) and Nickel Cobalt Aluminum(NCA), and creates daily usage profiles based on seasonal energy demand in twoSwedish cities, Gothenburg and Luleå. The degradation models are considered asconstraints. Two optimization methods are used. The first one is based on ModelPredictive Control (MPC) with IPOPT solver, using current as the decision variableto maximize daily revenue. The second one is based on Genetic Algorithm (GA)with the DEAP framework, using power as the decision variable to minimize dailycost. In Frequency Containment Reserve (FCR) service, the results show that inmost cases both methods can generate optimal charging and discharging strategiesunder different usage conditions, saving at least 4 % in summer. The battery canstill achieve profits while limiting degradation, which reflects that the model has thecapability to balance revenue and battery lifetime.