  The energy grid is currently undergoing a historic change of state from the
traditional structure where a utility owns the generation, transmission and
distribution services into an integrated smart grid in a monopolistic market
which introduce consumers as active players in managing and controlling the
power. This evolution adds more complexity to the energy scene as it requires
an unprecedented partnership of different fields and technologies to establish
successful integration of components with a bidirectional transfer of
information and energy. The Smart Grid Interoperability Panel (SGIP) was
incorporated in late 2009 to oversee the efforts in defining a set of standards
and interoperability layers to ensure a secure integration and operation of
various elements of the system. This paper discusses the smart grid concept as
a system-of-systems (SoS); analyzes the interoperability framework models
developed by SGIP and the European Union Smart Grid Cooperation Group
respectively; presents the stakeholders as domains and zones associated with
the interoperability layers; and illustrates other architectural concepts such
as fault-tolerance, software integration platform and design characteristics of
smart grid as an elegant system.
