Towards the Complete Self-Sufficiency of a nZEBs microgrid by Photovoltaic Generators and Heat Pumps: Methods and Applications

The present paper proposes a multidisciplinary procedure to correctly design a microgrid of all-electric nZEBs (nearly Zero Energy Buildings) from both electrical and thermal points of view. The procedure is suitable for new buildings supplied by local renewables, without the use of fossil fuel and with zero emissions. First, the thermal demand of each single nZEB is assessed, as a function of the installation site, building layout and physics, and material composing the envelope. Thanks to heat pumps, the thermal demand is transformed in electric load. Thus, the total electric consumption profiles, which include user's appliances and heating/cooling, are studied and compared with Photovoltaic (PV) generation supported by electrochemical storages. Both PV and batteries are simulated thanks to appropriate models. Regarding the PV production assessment, the present work proposes an improvement with respect to the use of traditional models, and it is based on experimental results on PV generators of recent production. The design methodology is applied to a real case of “energy community” composed of three nZEB units, that will be built in the campus of Politecnico di Torino, available to students and staff. The three units share PV production and storage capacity to reach the complete grid-independence.