Cities are predicted to host 80 % of the populations by 2050 considering the current urbanization rate. It is inevitable. No choice is left to us but to keep our cities clean and livable. Efficient use of energy is tightly linked with the smart cities. Looking at the technology development trends and the extensive need for efficient use of energy, cities must be transforming to smart ones in order to keep them clean and livable for this and generations to come. Kabul city population has been growing so rapidly and also expanding widely to its outskirts in the last two decades. Environmental footprints have been so significant and diverse. One of the critical issues with Kabul city has been the access to clean and abundant sources of energy. At the same time, lack of a master plan for its future has made this city in the danger of becoming empty from the habitants in few decades. This is very important to draw future now. Develop a new vision for our cities that is meeting the requirements of future. Kabul city needs one badly. One important area of a city to be discussed is its energy demand, supply and consumption. In this research, energy demand, sustainable sources of energy supply and consumption are thoroughly discussed. Based on our key assumption, livable and clean Kabul, all the other parameters are analyzed and suggested. In specific, we have discussed the energy demand for electricity, heating & cooling of buildings, transportation and industry. It is also assumed that Kabul will be modern and smart city with state of the art technology available all around it. Key data and references for this research are: 1. Sasaki Urban Design Framework for Kabul city, 2. Previous master plans of Kabul city, 3. Energy strategies and outlooks for Afghanistan, 4. Sustainable Development Goals (SDGs) and many other guidelines internationally used for urban planning and design. This research will help policy makers, urban planners and designers, municipality authorities, other urban issues related sectors to work jointly and make smart and rational decisions for the capital of Afghanistan and save it from going abandoned.