A case study of enhancing energy efficiency in battery-electric ferries through low-temperature heat pump integration
Year: 2025
Type: article
Abstract: This case study examines the potential for energy savings in all-electric battery-driven ferries through the integration of water heat pumps that utilise low-temperature waste heat for on-board heating. The principal objective is to enhance both energy efficiency and economic viability. A hybrid-driven diesel-battery-powered roll-on/roll-off passenger ferry operating in the Baltic Sea is analysed, using real-time data from power and heat flow measurements, energy flow analysis, and thermodynamic calculations. The study investigates the potential for retrofitting a 10 MWh battery system for full battery-electric operation. The findings indicate that heat pumps could satisfy over 50% of the HVAC nominal heat requirements, achieving a seasonal coefficient of performance (SCOP) of 3.5. The integration of heat pumps has the potential to reduce the vessel’s electric demand by 9.5% during a heating season, in comparison to direct electric heating.Nomenclature: ϵ: losses, %; ρ: density, kg/m3; η: second-law efficiency; cp: specific heat capacity, J/(kg K); E: energy, kWh; ΔH: enthalpy difference, kJ/kg; k: battery loss factor, √kW; m˙: water mass flow rate, kg/s; Pi: electric power (of part i), MW; Q˙i: rejected heat flow rate (of part i), kW; ti: time interval, Min.; T1/2: temperature inlet/outlet, °C; Th: temperature of hot reservoir, K; Tl: temperature of cold reservoir, K; V˙i: volume flow rate, m3/s. Technical abbreviations: BESS/ESS: battery energy storage system; COP: coefficient of performance; DoD: depth of discharge; EMS: energy management system; HEX: heat exchanger; HT: high-temperature; HVAC: heating, ventilation and air conditioning; LT: low-temperature; Ro-Ro: roll-on/roll-off; RoPax: roll-on/roll-off passenger vessel; SCOP: seasonal coeff. of performance; SOLAS: safety of life at sea (regulations); SW: seawater
Language: English
Subfield: Environmental Engineering
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4414926636