Sustainable decarbonizing a coal-dependent energy system faces significant challenges, particularly in countries where the entire energy infrastructure, social and economic activities are heavily reliant on traditional fossil-based technologies. These challenges are related to the fact that Kosovo and other similar countries have built their entire energy systems, social activities and economies around coal, making the transition to cleaner and sustainable alternatives a complex and multifaceted endeavor. This study investigates the overall Kosovo energy system balance while analyzing different sustainable scenarios that explore the design of the mix of technologies in electricity production while paving the way for smart energy system approach utilization. The critical excess electricity production method is used as a tool to identify what's happening with the energy system infrastructure and how Kosovo is uniquely dealing with that. Strategies for recovering old coal units with refurbishment and upgrading units, while integrating Wind and PV and introducing new technologies such as gas power plants without compromising natural resources (bioenergy) are investigated and finally discussed from a border preceptive to link with other spatial and international studies. The EnergyPLAN model, with technical simulation strategy, is used for modelling and scenario analysis of different sustainable transformative changes in the electricity technology production mix in Kosovo considering hourly balances of energy flows. The findings show that recovery of coal-based technologies and introduction of gas power plants with other studies on bioenergy, and increasing variable renewable can additionally contribute to creating a sustainable mix of energy production technologies while significantly contributing to climate change adaptability for heavily depended coal countries.