Nowadays, the whole world, including the European Union and Croatia, is turning to the use of renewable energy sources. From the Industrial Revolution, fossil-based technologies which contribute to CO2 emissions have been primarily used for energy production, and therefore many countries are working intensely on the energy transition. The Adriatic Sea shows the potential for future use of marine energy technologies. In this thesis, the potential of Blue Energy technologies in Croatia will be analysed. The observed technologies will include offshore wind farms, wave power plants and seawater heat pumps. The introduction deals with an overview of global, European and Croatian renewable energy sources. The next section describes Blue Energy technologies with regard to available parameters and their current state, as well as future potential. After that, the input data which was put into program EnergyPLAN was shown. This data is required for obtaining results that are related to the consumption, production, CO2 emissions and others. Data for 2018 which served as the starting point was presented, and then the forecasts for 2030 and 2050 were processed. Also, the relevant parameters for Blue Energy technologies were analysed. It was important to assess the possibility of their exploitation along the Adriatic coast of Croatia because the obtained capacities were put in EnergyPLAN. An analysis of production and the impact on CO2 emissions from these technologies was shown. Finally, a techno-economic analysis was carried out according to available data and forecasts for 2030 and 2050.