Climate change and energy security are issues facing municipalities throughout the world. Efficient, resilient, sustainable, community-based energy systems, such as district energy systems (DES), fuelled mostly by renewables, are an important tool for addressing both climate change and energy security at the municipal level. In spite of their benefits, DES are not widely adopted in Canada (CDEA, 2011). This is due to the complex nature of the barriers which project proponents face. This thesis examines the experience of the City of Prince George in adopting and implementing the Downtown DES. Using a case study methodology, data was collected through a review of relevant municipal documents and a series of semi-structured, open-ended interviews. A thematic analysis revealed unexpected barriers related to lack of adequate public consultation and negative perceptions regarding biomass as a fuel for the DES. These 'lessons learned' were then developed into recommendations for other municipalities considering DES.