CHARGING HYBRID IS THE FUTURE FOR FERRIES : A case study on partial electrification of the Gotland ferries in Sweden

Abstract: The Swedish climate target for the transport sector is that the emissions will be reduced by 70% by 2030 compared to 2010. A reduction of 27% has already taken place and a reduction of one million tons of CO2 per year remains until the target in 2030. In 2020, Sweden's domestic shipping accounted for 660,000 tons of CO2 emissions. Emphasizing the electrification of shipping will help achieve these goals In this thesis, the potential of partial electrification for Gotland ferries is investigated. Two ferries' assistance systems in Visby harbor will be electrified. Therefore, the transition from LNG use to electricity use is investigated in this work, where the energy demand, environmental footprint, and superficial economic aspects are investigated. The project client will have a solar park in the port that will generate electricity and the rest of the electricity demand will be purchased from the grid. OPTIMAX, which is an energy management system, was used as a simulation tool in this thesis. The consumption-based method which uses Life cycle analyses was used for CO2 calculations.  The results of the work were divided into two parts, one of which is a CO2 study conducted for the ferries where LNG use was compared with purchased electricity from the grid. Another study was done for the entire facility where OPTIMAX simulated future energy needs considering historical data, the solar park, part-electrified ferries, and the port's consumption. An Environmental Footprint was also examined for this part of the result.  The results from the consumption-based method and OPTIMAX showed an environmental benefit at the same time as an economic benefit. The economic benefit is calculated in the thesis without considering the investment costs, such as batteries, solar panels, and chargers. The results of this work showed that the use of OPTIMAX is a good idea to implement for controlling the electricity system. Since Swedish electricity is almost fossil-free, this type of project is very sustainable, as the results showed a big difference in environmental impact. This type of electrification would not give the same good results in other countries that do not use environmentally friendly energy sources. Such a project can lead to further electrification of other ferries/ships in other parts of Sweden to achieve the Swedish environmental goals.