The development of energy-saving behaviours is currently a key issue for improved power grid management and security. The smart-grid rollout serves these new needs, incorporating both smart meters that communicate consumption data to the supplier and information technologies conveying those data to the customers. Smart grids, as persuasive technology, should be the driving force of behavioural changes in energy saving. A smart-grid experimentation is currently taking place in Lorient (Brittany, France) as part of the SOLENN pilot project. Its purpose is to experiment with two families of smart grids in 975 households: technological smart grids and hybrids that provide information through technology and human support. An ongoing study investigates the SOLENN smart-grid appropriation process by taking a holistic perspective, either at individual, social, or societal level. The current study proposes an interdisciplinary approach based on theories from both ergonomic and sociological fields, namely instrumental theory (Rabardel, 1995), the appropriation approach developed by Proulx (2005), and the actor-network theory (Callon, 2006). This socio-ergonomic survey highlights the barriers and levers of the appropriation process and the development of energy-saving behaviours. The poster presents the first results of this study.