Techno-economic design optimization of hybrid renewable energy applications for high-rise residential buildings

This study aims to explore the techno-economic feasibility of renewable energy systems for power supply to high-rise residential buildings within urban contexts. Experiments on a photovoltaic (PV) and battery storage system under maximizing self-consumption and time-of-use strategies are conducted to study the system performance and validate energy balance based battery and energy management models. Four renewable application scenarios are investigated for a typical high-rise building in Hong Kong through coupled modelling and optimizations with TRNSYS and jEPlus + EA. A comprehensive technical optimization criterion integrating the energy supply, battery storage, building demand and grid relief indicators is developed, and the levelized cost of energy (LCOE) considering detailed renewables benefits including the feed-in tariff, transmission loss saving, network expansion saving and carbon reduction benefit is formulated. Experimental results show that root mean square deviations between the tested and simulated battery state of charge for the two strategies are 1.49% and 0.94% respectively. It is indicated that the PV system covers 16.02% of the annual load at a LCOE of 0.5252 US $/kWh and the PV-wind system covers 53.65% of the annual load at the lowest LCOE of 0.1251 $/kWh. The added battery improves the annual average load cover ratio and self-consumption ratio by 14.08% and 16.56% respectively, while the optimum PV-wind-battery system covers 81.29% of the annual load at an affordable LCOE of 0.2230 $/kWh. Techno-economic analyses of different typical scenarios can provide valuable references to related stakeholders for a promotion of renewable applications in high-rise buildings and further reduction of urban carbon footprint.