The Danish path to a sustainable energy system focuses on increasing energy efficiency and flexible consumption via smart grid technologies. Information and communication technology is fundamental for achieving these goals by enabling among others new methods and systems for data collection and decision support. This book chapter covers new data collection options exemplified in the concrete case of a living lab for smart grid technologies. Furthermore, the chapter covers the use of visualisation to design decision support for such collected data. We formulate energy management based on energy data as a visualisation problem in the nested model for information visualisation. We prototype a visualisation tool chain to produce a rich set of visualisations based on energy data from five commercial and industrial buildings. Finally, we present qualitative study results for the value of visualisations as an analytical tool. Building on the results we identify important information needs for users of data analysis tools.