Various territorial innovation models have been developed since the 1980s, offering a new perspective on how certain regional production systems have grown out of the innovation and training processes specific to particular local milieus. This article reconsiders this approach, both to take into account the greater mobility of resources, and to understand how innovation is constitutive of a broader system of socio-economic evaluation. Based on an enlarged theoretical debate and a comprehensive reading of the photovoltaic industry in Western Switzerland, the concept of the ‘innovative milieu’ is re-examined in the context of ever-increasing economic, political, and social interest in sustainable development. The notion of ‘multi-local valuation milieu’ is proposed as an exploratory framework to nurture new theoretical and policy debates regarding innovation and territories. JEL Codes: O31, L22, L26