Abstract
Reducing the primary energy consumption in buildings and simultaneously increasing self-consumption from renewable energy sources in nearly-zero-energy buildings, as per the 2010/31/EU directive, is crucial nowadays. This work solved the problem of nearly zeroing the net grid electrical energy in buildings in real time. This target was achieved using linear programming (LP)—a convex optimization technique leading to global solutions—to optimally decide the daily charging or discharging (dispatch) of the energy storage in an adaptive manner, in real time, and hence control and minimize both the import and export grid energies. LP was assisted by equally powerful methods, such as artificial neural networks (ANN) for forecasting the building’s load demand and photovoltaic (PV) on a 24 hour basis, and genetic algorithm (GA)—a heuristic optimization technique—for driving the optimum dispatch. Moreover, to address the non-linear nature of the battery and model the energy dispatch in a more realistic manner, the proven freeware system advisor model (SAM) of National Renewable Energy Laboratory (NREL) was integrated with the proposed approach to give the final dispatch. Assessing the case of a building, the results showed that the annual hourly profile of the import and export energies was smoothed and flattened, as compared to the cases without storage and/or using a conventional controller. With the proposed approach, the annual aggregated grid usage was reduced by 53% and the building’s annual energy needs were covered by the renewable energy system at a rate of 60%. It was therefore concluded that the proposed hybrid methodology can provide a tool to maximize the autonomy of nearly-zero-energy buildings and bring them a step closer to implementation.
Highlights
Buildings are responsible for 20% and 40% of the total energy consumption across the globe and the EU, respectively
The nearly-zero-energy buildings (nZEBs) concept, which is clearly defined by the EU Directive, arose from the general concept of a zero-energy building (ZEB)
While not officially defined, such buildings are connected to energy grids, have integrated renewable energy sources, use weighting systems to balance their demand with local renewable generation along with their carbon footprint, and aim to zero the exchange between the import and export energies during a reference period, which is widely accepted to be a full year [9,10]
Summary
Buildings are responsible for 20% and 40% of the total energy consumption across the globe and the EU, respectively. The directive required EU member states to transform governmental buildings into nZEBs in 2018, and to develop new policies and guidelines for applying the nZEB requirement in all new buildings from 2020 onwards [6]. Both academics and professionals continue to seek methods to make these buildings adoptable, practical, and, undoubtedly, economically feasible. The nZEB concept, which is clearly defined by the EU Directive, arose from the general concept of a zero-energy building (ZEB). The nZEB concept requires a building to have a low energy consumption and to maximize its energy autonomy as much as possible
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
