According to the literature on regime tran-sition, niches are sources of innovation that may lead to the transformation of the dominant regime, if pro-cesses at other level of the system –the landscape and the mainstream regime -are supportive. A focus on actors involved in the transition process and the analysis of their specific role in knowledge networks can help assessing the robustness of a specific niche and its growth potential. Knowledge systems, and in particular the dynamics of local and expert knowledge, have in fact a key role in innovation mod-els.