Josh's House is a “living laboratory” research and demonstration project in the Perth suburb of Hilton, Western Australia. The scope of Josh's House included the design and construction of two energy efficient family homes that achieved the highest level, 10-stars (estimated thermal load: 4 MJ/m2/year) [Australian Government Department of Environment, Star rating scale overview, 2015 (Online), http://www.nathers.gov.au/owners-and-builders/star-rating-scale-overview, accessed on: 2017/17/07], under the Nationwide House Energy Rating Scheme. The project partners include the Co-operative Research Centre for Low Carbon Living and Curtin University. In mid-2015, a further research component was added to Josh's House involving the installation and ongoing monitoring of a battery storage system. This system is a domestic example of a distributed energy storage system (DESS) and is here referred to “Josh's Battery” or “the DESS”. The aim of the project is, in the first instance, to make domestic DESS data publicly available. Broader project objectives are to trial the technology, test assumptions on performance, document and communicate lessons and outcomes, and to inform further research and development. This paper provides an analysis of the monitoring data produced during the energy storage system's first year of operation. Particular areas of interest include: interaction with the electricity grid before and after installation of the storage system; correlation of system performance to specifications and modelled predictions; anomalies and unexpected results; and lessons learned from the installation and operation of the system. Implications and influences. The significance of this research is that it is built around the first monitored, grid connected domestic energy storage system in the Perth metropolitan area. It provides unprecedented data on how these systems can be expected to operate when embedded into a large-scale electricity network. The project also gives the opportunity to test some fundamental assumptions about these systems and feed into policy and business case development for the distributed energy storage sector, more broadly.