The transformation of electrical grids into smart-grid is seen as one of the major technological challenges of our times and at the same time as one of the key domains for Internet of Things (IoT). Smart-home technologies and corresponding analytics are an integral part of many use cases in this field. In this paper we present a cloud-based test bed for capturing and analyzing smart-home data and report on experiences from a 3 year pilot with a cloud-based system. We discuss on real-world challenges that we encountered throughout the pilot - e.g. related to big data volumes and data quality - and describe corresponding technical solutions.