A district energy system includes at least one energy provisioning unit, an energy management controller; a thermal distribution network coupled to the energy provisioning units and to a plurality of coupling interfaces connectable to the associated HVAC system of buildings within a district, and an electrical distribution network coupled to the energy provisioning units and to the coupling interfaces. The coupling interfaces may include both heat pumps and heat exchangers at each building, to provide heating, cooling and enable harvesting of normally wasted thermal energy from the buildings for re-distribution. The controller can manage the selection and number of energy provisioning units (and their operational set points) coupled to the district thermal distribution network and the electrical distribution network to meet the thermal and electrical demands of the district while satisfying other operational goals such as the minimization of greenhouse gas emissions.