Environmental and operative impact of the electrification of a double-ended ferry

Abstract

The increasing sensibility to the environment protection and emission reduction in the atmosphere is also influencing the maritime shipping. The more restrictive regulations on pollutants suggest the adoption of alternative onboard propulsion and energy generation systems. To this end, electrification is a promising solution for pollution reduction, giving some flexibility on the strategy to use for the onboard system. Moreover, a hybrid-electric system can be combined with the exploitation of green fuel, increasing the potential reduction of total emissions. However, the final efficiency, both in term of emission reduction and expected operative expenditure, is strongly influenced by the operative profile of the vessel. This is of utmost importance both in case of a newly designed vessel and in the retrofitting of an existing one. In the present work, the impact of electrification on a double-ended ferry is presented, taking into consideration the operative profile of the vessel derived from real navigation data.

Electrical and Energy Systems Integration for Maritime Environment-Friendly Transportation

“…This is coherent with the scope of the paper, which is the definition of the shore infrastructure required for supporting a given ship. A green ship design can be obtained by means of a data-driven design approach, such as the one presented in [18], which allows to optimize the ship towards specific requirements (environmental friendliness on a specific route in this case). The bullets c and d address the port existing infrastructure (electrical equipment of its power system and loads), while bullet e points towards already planned port power system improvements (such as substation revamping, installation of new loads, power lines substitution, etc.).…”

“…The ship is a bi-directional Ferry using the series-hybrid (SH) architecture discussed in [18]. In particular, the ship is endowed with a hybrid propulsion configuration, which include electrical propulsion motors, an integrated power system with Diesel generators, an energy storage system, and a shore connection.…”

“…The ship daily operative profile directly results from its route. In this case study, reference is given to the route presented in [18,19], connecting two small ports in Croatia (Brestova and Porozina) and providing both passengers and vehicles crossing services. A complete crossing from one port to the other is 35 min long.…”

“…The ship speed profile during the navigation phases (maneuvering and sea navigation) can be found in [18]. By using the ship power-speed curve and the speed profile it is possible to evaluate the propulsion power needed during the crossings.…”

“…The second onboard ESS recharge concept implies installing a high-power shore connection in the port, to perform a fast-charge during the 15 min the ship stays at berth each trip. In this case, the SC power level has been defined following the ship requirements stated in [18]. Therefore, a 750 kW MV-SC is used, allowing the onboard ESS refill with up to 187 kWh during daily berthing time (provided that the onboard ESS is designed for accepting the charge pulse).…”