Based on interviews of users’ experience with current smart-meter technologies the authors propose, implement and evaluate a user-centered design of an energy-use information system that assists private households in making efficient energy consumption decisions. Instead of providing disaggregated data, the envisioned system automatically calculates the monetary savings from replacing an appliance or by changing the operational behavior of an appliance. The information provided is personalized with respect to appliance use and also comprises information from external databases. A prototype is implemented and evaluated in a use case with white goods household appliances. The study concludes with directions for further interactivity improvements and research into the structures of an openly shared appliance database.