We present a hierarchical distributed communication and control architecture for Smart Grids. The proposed topology consists of multiple layers to allow for robust and flexible data access and resource allocation in large decentralised Smart Grid systems. We introduce a scenario involving different Smart Grid actors, and develop an architecture using Linked Data principles (a set of standards for data access on the web). We propose a simple language to express allocation constraints, and map the resource allocation problem to a constraint satisfaction problem. We further provide initial experimental results for decentralised data access and resource allocation in Smart Grids.