An explanation is provided as to why home energy management system performance in field trials is so inconsistent. Design of a home energy management system using a participatory design exercise with three eco-communities as lead users. A set of highly novel interfaces were co-designed and tested. Designs were radically different to the norm and yielded sustained user engagement over a six-month monitoring period. User-centred design may hold the key to unlocking the energy saving potential of new domestic technologies.