This paper presents a method to analyze the technical and economic potential of combining different types of resources to provide grid services, with a particular focus on battery systems. The paper proposes a modelling paradigm where resources are described with few key operational parameters and describes a control architecture to co-operate the combination of resources to offer fast grid services, taking as an example the provision of secondary frequency control in the Swiss market. A sensitivity analysis is reported that highlights the ability of the combination of energy resources to provide grid services as a function of their technical characteristics.