The aim of the Young Cities Team 2 sub-project “Energy Infrastructure systems” consists of the development and the design of energy efficient buildings and energy supply systems for new Towns in Iran. This document gives an overview over the design and the development of the energy supply systems for the 35 ha pilot area in Hashtgerd New Town. In general, these energy concepts are suitable for the supply of all types of buildings (residential, commercial, cultural, etc.), but in this paper the focus lies on the energy supply of residential buildings. It is possible to reach the aim “energy efficiency” through several methods, for example by using common Iranian building technologies in different ways, or through the improvement of these technologies. Another possibility lies in the use of available renewable energy sources, for example the very high potential of the solar irradiation in combination with solar thermal technologies for heating and cooling. Energy efficiency can be also realized with new introduced building technologies, such as centralized, semi-centralized and de-centralized energy supply systems, based on co- and tri-generation technologies and district heating networks. The first step was a climate analysis for the location Hashtgerd New Town as the base for the energy demand analysis and for the determination of the environment energy potential. Based on these results, an energy demand analysis for the different residential building types was carried out. The next step was the design of four efficient energy supply systems, which were compared to each other regarding to their primary energy demand, their carbon dioxide emissions and their energetic life cycle costs. In the end, one of the systems is recommended as the “favorite system” for the supply of the 35 ha pilot area.