The overall objective of WP2 is to provide a synthesis of alternative system architectures for the future Danish electric power transmission and distribution system. A power system architecture is the specification of operating objectives, functions and components and their mutual relations in the electrical power transmission, distribution and user (generation/consumption) subsystems including associated subsystems for data acquisition, coordination, control, protection and their links through communication networks. The architecture defines accordingly the services the power system and its components offer to the energy system as a whole and to its own internal subsystems and the intelligence provided by the data acquisition, coordination, communication and control subsystems. The architecture does not presuppose a particular technological solution for subsystems. Rather, power system architectures may be implemented by alternative technologies and composed of different technologies serving different purposes (e.g. markets for coordination and protection schemes based on a hierarchical command structure). According to the abovementioned definition, the market based power system architecture is an architecture which uses market mechanisms as a technology to manage energy generation, transmission, distribution and consumption resources in the power system. Definition of a system architecture requires a combination of analysis of possible solutions and a top down approach to solution independent system requirements and associated architectures. Therefore, the work has been divided into the following three subtasks: • Review of innovative power system solutions • Analysis of requirements • Possible System Architectures The three subtasks are specified in more detail below and results of the work are presented throughout chapters 1.1, 2 , 2.2. WP 2 utilizes results from the EcoGrid.dk WP4 (measures).