Global efforts to mitigate climate change rely on a transition towards renewable energy systems. Mountain regions, with their high potential for solar energy production, are increasingly being targeted for the installation of solar energy systems, such as ground-mounted photovoltaics. However, the siting of these systems in mountain areas can impact ecosystem services, such as habitat quality and recreation potential. These impacts are further influenced by climate and land use changes, as well as changes in people’s worldviews, beliefs and values, which come along with large uncertainties. Therefore, it is essential to assess uncertainties and their effects on the ecosystem services impacts of solar energy systems, ultimately informing the selection of suitable sites that are robust to future changes. We present a spatially explicit, expert-based Bayesian network that quantifies uncertainties in assessing ecosystem services impacts of solar energy systems under future changes. The model integrates data from scientific literature, expert knowledge, and future change scenarios, including exploratory and normative scenarios, to identify suitable locations for solar energy systems in Switzerland, which are robust to future changes. Expert knowledge is collected through an online questionnaire, engaging representatives from academia, private sector and public institutions, with a particular focus on the Alpine region. This study provides insights that can support planners in selecting suitable locations for solar energy systems while considering ecosystem services impact under uncertainty.