A case study of a commercial/residential microgrid integrating cogeneration and electrical local users

European energetic policy aims to complete the liberalization market process and to improve a rational use of energy promoting strongly ‘Nearly Zero-Energy Buildings’ NZEB and the use of highly efficient cogeneration CHP also for residential/office/commercial buildings. NZEB means a building that has a very high energy performance, and the very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including CHP. The actual promotion of renewable energies and distributed generation obliges to review the traditional “load-driven” “top-down” power system. Electric demand side management (DSM) focuses on changing the electricity consumption patterns of end-use customers through improving energy efficiency and optimizing allocation of power. Demand response (DR) is a DSM solution that targets residential and commercial customers, and is developed for demand reduction or demand shifting at a specific time for a specific duration. Renewable power and CHP systems can be sized and managed more efficiently for loads of tens of kVA, more than an individual consumer. So, it is necessary for small and medium consumers, to aggregate their load profile in order to reach a threshold value of some ten of kW and a more demand flexibility like the Heating System where a unique boiler supplies more efficiently the building. The actual regulatory rules don't permit the aggregation of consumers in a unique Point of Delivery POD. The paper presents a case study of a microgrid arranged for a complex of two commercial/residential buildings in order to overcome the regulatory barrier mentioned and propose a load management strategy aimed at controlling the power withdrawal at the POD. The authors suggest the ecodesign of the residential and commercial low voltage distribution like a microgrid allows to guarantee a reduced impact as ever net load on the net supply at least in a first evolution.