An example of smart building with a km zero energy performance

Environmental concerns and European policies push for more energy efficient buildings, towards the goal of Nearly Zero Energy Buildings (nZEBs), buildings with an high efficiency and for which the low amount of energy required for the fixed technical systems (TBS) is covered by energy from renewable sources produced on-site. Innovative technical solutions and social/economic schemes are key elements to this purpose. Results on the simulation of energy performance and control system behavior of a real case are analyzed. The paper shows that the sizing of the local photovoltaic system (PV) based on the yearly energy spent by the TBS allows to obtain the nZEB qualification but it doesn't determine an optimal power behavior. The solution proposed in this work is to arrange a microgrid with a unique point of connection to the grid that includes the local generation systems, the common electric heating system by source grounded heat pumps and the residential units of a part of the buildings. Sizing of on-site power generation from renewable sources, like PV, may be developed based on the energy demand. The microgrid is managed by a common building automation control system (BACS). Control strategies have been analyzed, in order to realize demand-side management (DSM) actions, combining the advantages of thermal inertia, flexible loads, energy pricing and local generation. The DSM strategy operating on the controllable loads and on the electric and thermal storage can reach a “near zero power behavior” so the building can become a “km zero energy building” (KZEB).