The purpose of this dissertation is the feasibility study for the retrofit of an open
type passenger ferry into a fully electric ship. The analysis is based on existing ships
that cover specific ferry lines. More specifically, the following ferry lines are going to
be studied: Perama Megaron - Faneromeni Salamina, Perama-Paloukia and finally
Oropos - Eretria. These ferry lines are of great interest, as the ships that cover these
routes make several itineraries per year, and as a result the benefits become
significant for both the shipowner from the reduction of operating costs and for the
environment from the reduction of emissions.
Initially, in the first chapter of the dissertation, an analysis of Short Distance Shipping
in Europe is made, the aim of which is to illustrate its importance in world trade. A
typical example of a country in which the Short Sea Shipping is dominant, due to its
several ferry lines, is Norway, which is one of the first countries that promote the
construction of electric ships in order to cover these routes. In the same philosophy,
Greece is also a case of a country which has numerous ferry lines, and as a result
whether the conversion of existing ships into electric or their construction from the
beginning is a completely realistic choice.
Furthermore, the second chapter of the dissertation is presented, which focuses on
the different types of lithium ion batteries. Lithium-ion batteries are an excellent
choice for industrial applications as they have excellent properties in terms of
thermal stability, high values of specific energy and a large number of operating
cycles. The aim of the chapter is to identify the optimal battery type which is going to
equip the electric ship and at the same time to determine the best operating
conditions of the battery.
In addition, the next chapter presents the basic equipment that will be used on the
ship such as the battery and BMS, electric motors, inverters and Azipod thrusters. At
the same time, emphasis is placed on the layout of the batteries and the number of
battery packs that will be installed on the ship, while special mention is made for the
electric power supply network of the ship.
The fourth chapter of the dissertation presents the development of a specific
methodology for the realization of the techno-economic study. More specifically, the
methodology is based on the energy requirements of the ship in port and voyage
and finally the aim is to calculate the installed capacity of the batteries in the ship,
taking into consideration a specific charging scenario, the charging current and the
maximum depth of discharge of the battery. The annual operating costs of the ship
before and after the retrofit will be determined and finally the sustainability of the
investment will be studied.
The fifth chapter will present an approximate method for determining the ship's
resistance to its service speed, with the aim of finding the maximum operating load
of the engine. The maximum operating load of the engine during the trip is
important to be determined even approximately, because it is one of the most
important energy demands.
Then the scenarios and the final conclusions for all the ferry lines mentioned above
will be presented in separate chapters. Finally, in the last chapter an approach to the
environmental benefits derived from the retrofit will be made, and furthermore an
effort to quantify emission reductions due to the retrofit of ships to fully electric for
the lines studied.
(EN)
National Technical University of Athens
