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Integrating PV panels into building facades (BIPV) necessitates a comprehensive understanding of the PV system’s impact on building energy consumption within the site’s climate zone. Maximizing PV power output depends on factors such as location, climate type, and latitude. However, minimizing total electricity consumption, which includes cooling, heating, and lighting loads, is significantly influenced by the design of the PV system and the climate region. This study conducted a thorough evaluation of the impact of south-facing PV-integrated louvers on both PV power generation and building energy performance, as well as occupants’ visual comfort, across 17 ASHRAE climate regions in the U.S. The results indicated that south-facing PV-integrated louvers significantly reduced building energy consumption in climate zones 1 to 3, as well as 4B and 5B. Wider louvers with longer spacing (S-3 typology) were particularly effective in zones with moderate cooling needs (climate zone 4). However, in colder climates (6–8) with significant heating demands, roof-mounted systems provided a better balance between power generation and solar heat gain for the building. The PV-louver designs effectively reduced sunlight penetration and maintained illuminance levels within the desired range across most of the floor area. Conversely, roof typologies exhibited lower lighting loads but resulted in significantly high mean illuminance levels on the working surface, leading to disturbing glare for occupants across a large portion of the floor area. The findings of this research offer practical implications for architects, engineers, and policymakers seeking sustainable building solutions. 

Integrating PV panels as a source of clean energy has been a widely established method to achieve net-zero energy (NZE) buildings. The exterior envelope of the high-rise buildings can serve as the best place to integrate PV panels for utilizing solar energy. The taller the building, the higher the potential to utilize solar energy by PV panels. However, shadows casting on the BIPV façade systems are unavoidable as they are often subject to partial shades from panels self-shading as well as building walls. Partial shading or ununiform solar radiation on the PV surface causes a dramatic decrease in the current output of the circuit. For that reason, in BIPV facades the default circuit connection of manufactured PV panels does not output maximum power under partial shading conditions. This paper investigates the different circuit connections in BIPV façade system to achieve higher energy yields while addressing design requirements. To this end, PV power production in different circuit connection reconfiguration scenarios was explored in two levels of BIPV components: 1) PV cells, and 2) strings of PV cells. Experimental tests conducted to validate the simulation results. The results of this study indicated that the maximum power generation occurred when the circuit connection between cells within a string is series, and the circuit connection between the strings within a PV panel is parallel. Results of the experimental tests shown that the series-parallel circuit connection increases the energy yields of the BIPV facades 71 times in real-world applications. The comparison analysis of the Ladybug energy simulations and the proposed analysis Grasshopper analysis recipe power output showed that the developed Grasshopper script will increase the BIPVs energy yields by 90% in simulations. 

With the rapid urbanization and growing energy use intensity in the built environment, the glazed curtainwall has become ever more important in the architectural practice and environmental stewardship. Besides its energy efficiency roles, window has been an important transparent component for daylight penetration and a view-out for occupant satisfaction. In response to the climate crisis caused by the built environment, this research focuses on the study of net-zero energy retrofitting by using a new building integrated photovoltaic (BIPV) curtainwall as a sustainable alternative to conventional window systems. Design variables such as building orientations, climate zones, energy attributes of BIPV curtainwalls, and glazed area were studied, to minimize energy consumption and discomfort hours for three cities representing hot (Miami, FL), mixed (Charlotte, NC), and cold (Minneapolis, MN). Parametric analysis and Pareto solutions are presented to provide a comprehensive explanation of the correlation between design variables and performance objectives for net-zero energy retrofitting applications.