The survival and development of individuals and human communities (as well as the plant and animal world) is unthinkable without energy. Production and supply of energy to consumers is based on the basic groups of main sources: 1. fossil fuels; 2. renewable energy sources; 3. nuclear energy. Today energy supply is a precondition for economic development and population standards, and development of energy affects on many economic sectors itself. So far the importance of energy economic activity and economic growth becomes unquestionable. As far as the Croatian energy sector is concerned, the dominant part is organized into two major systems: INA (Oil Industry) and HEP (Croatian Electricity Industry). Croatia has many opportunities in the energy sector, but it is bad or poorly used. That is why it is important to create a quality energy strategy in this area that will make the most use of renewable resources in order to import less energy in order to continue to export it in the future, which would also affect the economic growth of the country. But it is important to do everything to provide quality sustainable development in the future and protect the environment, relatively, all the natural resources and wealth that Croatia has.