The optimization of heat sources in populated areas is associated with the optimization of their structure. The optimization problem is of linear discrete nature and is hard to formalize [1]. The aim of the optimization is to identify the types, sites and mix of equipment of the heat sources. Moreover, this optimization problem is closely related to the scheme and parameter optimization since the equipment mix of heat sources and their connection to existing (newly constructed) consumers determine the heat network configuration. The emerging new trends in the technological development of heating systems require a significant correction of stating and solving typical technical and economic problems to design these systems, which, in turn, predetermines the transition to a new level of their methodological support [2]. The paper proposes a mathematical formulation of the problem of optimal development of heat sources and considers a methodological approach to solving it, including effective load distribution between heat sources, and calculation of the optimal heat network configuration, given the minimum environmental impact of heat sources.