Biomass micro district heating networks can represent an opportunity for small communities to comply with European directives and achieve a sustainable energy supply. To foster their adoption, a facility management provider should rely on methods and tools to properly size the biomass energy conversion system, so that it can better suit the local community characteristics and requirements. To this end, the concepts of partial and complementary degrees-hour are introduced in order to partition energy flows along the whole heating season between the biomass boiler and the fossil fuel peak load one for each possible biomass boiler size. Basing on such division, the operational profile of the plant and related costs as well as carbon dioxide equivalent emissions can be evaluated. The methodology is embedded in a decision support tool, which provides the minimum cost solutions as well as the more environment-friendly ones. Results from the application of the tool to a real case of a mountain village are discussed.
