# Developments, Trends, and Challenges in Optimization of Ship Energy Systems
## Appendix A Main Characteristics of Journal Articles on Optimization of Ship Energy Systems
(2016) [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] _Applied Energy_**2016. ** Experimental work in the laboratory: performance evaluation of PV on a swinging platform. System: PV modules, diesel generator, and a NaS battery as ESS. Five loading conditions are considered pertinent to an oil tanker. Design (battery sizing only) and operation optimization. Objective: minimize cost of fuel + cost of battery. Independent variables are the power output of the diesel generator and the capacity of the battery. Method: interval optimization. Algorithm: INTLAB-Version 5.5 with MATLAB. * [PERSON] (2016) [PERSON] _Energy_**2016. ** System: transcritical ORC using heat from exhaust gas, cylinder cooling water, scavenge air cooling water, and lubricating oil from a marine diesel engine of 68,640 kW in a merchant ship. Various fluids are investigated. Design optimization. Objective: minimize levelized energy cost (LEC). Independent variables: pressure and temperature of the working fluid at the inlet of the expander. Solution procedure: first derivative of LEC with respect to each independent variable equal to zero. * [PERSON] and [PERSON] (2017) [PERSON]; [PERSON] _Journal of Engineering for the Maritime Environment_**2017. ** System: ORC with heat from the cooling circuit (charge air, cylinder cooling water, and lubricating oil) of a contanisership. SDO optimization: four operating states. Partial load performance of the ME. The HEATSEP method is used for optimization of the heat exchanger network. Objective: maximize NPV. Algorithm: GA determines a near optimal solution, while GRG2 determines the optimal solution. * [PERSON] et al. (2017) [PERSON]; [PERSON]; [PERSON]; [PERSON] _Energy Conversion and Management_**2017. ** System: combination of EGR with Rankine cycle using heat from the cooling circuits and exhaust gases of the two-stroke ME (MCR 23,000 kW). Two configurations are studied: (1) with double-pressure steam turbine and (2) with triple-pressure steam turbine. Design optimization. No partial load performance. Objective: maximize net power output. Algorithms: SQP for configuration 1 and GA for configuration 2. * [PERSON] and [PERSON] (2017) [PERSON]; [PERSON]; [PERSON] _Desalination_**2017**. System: two-stage ORC using heat only of the exhaust gases of the diesel engine and reverse osmosis desalination unit. Design optimization at nominal point. Biobjective: maximize energetic efficiency and minimize total unit product cost. Algorithm: GA.
* [PERSON] et al. (2017) [PERSON]; [PERSON]; [PERSON]; [PERSON] _Applied Energy_**2017**. System: three configurations of ORC operating on waste heat of Marine Diesel Engines. Modeling: design and off-design, steady-state, and dynamic models. Design and operation optimization taking partial load into consideration. Alternative configurations are compared. Four operating states. Objective: maximization of the net power output of the ORC. The system is so designed that it reaches stable operation after transient conditions (change of ship speed and, consequently, power output of the main engines) in a reasonable length of time. * [PERSON] and [PERSON] (2017) [PERSON]; [PERSON]; [PERSON] _Thermal Science and Engineering Progress_**2017**. System: supercritical CO\({}_{2}\) regenerative recompression Brayton cycle (RRCBC) with heat from marine gas turbine. Energy and exergy analysis. Optimization: only the pressure ratio for maximizing efficiency at design point is determined by drawing related diagrams. * [PERSON] et al. (2017) [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] _Energy_**2017**. System: diesel generator and PV with hybrid energy storage comprising lead-acid battery, Li-ion battery, and supercapacitor in an oil tanker. The motion of the ship, including rolling, is taken into consideration in calculating the electric power produced by the PVs. Method of analysis: a frequency analysis of the imbalanced power, i.e., the power not covered by the PVs, is performed by Discrete Fourier Transform (DFT).