An analysis of the benefits of photovoltaic-coated glazing on owning and operating costs of high rise commercial buildings

Energy efficient glazing is necessary to reduce heat gains or losses that contribute to the high-energy use of buildings. However, high-rise commercial buildings that use energy efficient glazing are still consumptive. To reduce their energy use further, recent studies have integrated photovoltaic glazed window systems into the building shell. With limited light transmittance due to their required production of electricity, photovoltaic glazed windows can be developed with thermal properties similar to Low-E coatings. Consequently, these window systems can reduce operating costs of buildings without reducing the human satisfaction of the built environment. To understand the relationship between photovoltaic windows, energy use and human satisfaction, this study investigates the effects of photovoltaic glazed windows on energy use of large commercial buildings and includes an assessment of the overall human satisfaction of the workers within photovoltaic glazed office spaces. This study targets high-rise commercial buildings and their occupants in urban centers of the four census regions—North, Northeast, South, and Midwest. A prototypical building was used to develop the base case simulations for the DOE-2 energy simulation program and the PV F-Chart photovoltaic analysis program. By substituting the appropriate variable in the base case simulation for each site, building was simulated to evaluate the impact of the PV glazing on the building's heat loss/gaining as well as the amount of electricity that could be expected from the PV. To test for human satisfaction, a survey was performed to assess the overall preference of the subjects to the office spaces using the photovoltaic glazed windows. An analysis of the variance was also conducted to test for significantly different treatment means. Overall, the findings of this study show that photovoltaic windows significantly decrease the energy used by high-rise commercial buildings. Payback periods 11 to 20 years could be expected for buildings using energy efficient PV glazing in the Houston, Los Angeles, Detroit, and New York, when compared to single-pane clear and Low-E glazing. When assessing the effects of clear glazing and PV glazing on human satisfaction, the data revealed that lower levels light transmissions and visibility do affect the satisfaction of workers. Although, these effects are seen as significant, they are not perceived to be negative or undesirable.