Positive Energy District (PED) is a characterization used by the European Union to increase the speed of the transition to climate friendly urban areas. A PED is an area which is a net producer of usable energy. The concept originates from energy-positive buildings, but includes the possibility of collaboration between buildings adding the synergies that are made possible by considering a larger area. Each building can be considered as an independent system, and thus the entire PED is a system of systems. By combining capabilities, the different buildings within the PED together achieve greater energy efficiency. In this paper, we describe a PED as a system of systems and take steps towards comparing this view of PEDs with a simpler view based on the seven samurai model of intervention systems. The two approaches give different insights to understanding the PEDs