Thermal and optical investigations of various transparent wall configurations and building integrated photovoltaic for energy savings in buildings

The growing global attention on energy consumption in buildings, along with the harmful effects of carbon dioxide emissions on climate change, has recently heightened efforts on sustainability and energy savings in buildings. As a result, the search for high thermal resistance walls, as well as the development of integrated photovoltaic technology with front glass walls to save energy in buildings, is an important and promising topic. The current study investigates and compares the energy-saving capabilities of four building transparent wall configurations: basic glass, facade, basic glass integrated with photovoltaics, and facade integrated with photovoltaics at different ambient temperatures, wind speeds, and solar radiation. The study also introduces a comprehensive three-dimensional heat transfer and electrical model that combines a Steady-State Thermal solution with the ANSYS mechanical solver and a fluid flow solution with the ANSYS Fluent solver to simulate the full layers of Cadmium Telluride solar cells, transparent walls, and the air conditioning room. Each model was subjected to a full-day simulation using Egypt weather conditions in the summer season to evaluate the efficacy in terms of saving artificial lighting loads, thermal loads for air conditioning, daily electricity generation from Cadmium Telluride solar cells, and total energy savings throughout the day. According to the findings, the facade integrated with photovoltaics and basic glass integrated with photovoltaics configurations deliver about 394 Wh/ m2 of electrical energy to the building daily. Furthermore, when air conditioning and lighting loads, as well as solar cell productivity, are considered, the facade, basic glass integrated with photovoltaics, and facade integrated with photovoltaics configurations save 46.9%, 31.5%, and 79.3% of total electricity consumption, respectively, when compared to the basic glass wall.