Hybrid solar-wind renewable energy systems with energy storage for net/nearly zero energy buildings: An uncertainty-based robust design method
Menglong Lu, Zhihua Wang, Zhenjun Ma
Abstract
Net/nearly zero energy buildings (NZEBs) are recognized as pivotal solutions to reduce building energy consumption and advance sustainable development. Existing studies often used traditional methods to facilitate the design of renewable energy systems (RESs) under deterministic conditions, which may fail to achieve the design targets of NZEBs during their service life. Considering uncertainty correlation and equipment degradation, an uncertainty-based approach was proposed in this study to robustly design RESs in NZEBs. Firstly, scenarios were randomly generated considering correlated uncertainties. A novel scenario reduction technique, which considered correlation loss while reducing scenarios, was then introduced to improve the optimization efficiency. Furthermore, the potential of NZEBs in reducing carbon emissions was explored by evaluating the environmental impact of various RESs using hourly marginal emission factors. Lastly, the optimal design solutions were identified and analyzed based on the specified targets of various NZEB definitions. The results indicated that, compared with the first year, the annual energy supply, net energy, and carbon emission reduction decreased by 28.2 %, 52.2 %, and 51.3 %, respectively, after 20 years of operation. The traditional design scheme failed to consistently achieve the predefined NZEB targets throughout the system's service life. In contrast, the RESs designed using the proposed approach exhibited reliable performance, consistently meeting the requirements under various NZEB definitions and achieving an average self-sufficiency ratio of 89.1 %, validating its energy autonomy throughout the system's operational lifespan. The proposed method can effectively result in robust design of RESs in NZEBs while satisfying the design targets of economic-technical-environmental dimensions under uncertainties. • A design method for energy systems in NZEBs under uncertainties was developed. • Uncertainty correlations were considered for both scenario generation and reduction. • Carbon emissions were evaluated considering the time varying grid carbon intensity. • The reliability to achieve specified targets of various NZEB definitions was proved.