Environmental damage and saving benefit of external shading devices via photovoltaic (PV) energy generation

The aim of the study is to evaluate both environmental damage and saving benefit in selecting building shading devices. The environmental damage from the production and construction (P&C) of shading devices is evaluated. The saving benefit, i.e., decreasing building operation energy (OE), due to installing shading devices is evaluated. A simple office building module is used. The external shading devices are constructed from concrete-based external shading devices and aluminum-based light shelf devices. Energy design via Life Cycle Energy Assessment (LCEA) and environmental design via Life Cycle Assessments (LCA) are applied. Environmental design is performed when PV energy generation is used. It was found that in energy design, 40% of building OE saving benefit is required to compensate energy needed for the P&C of shading devices. In environmental design, 100% of the building OE saving benefit is required to compensate for environmental damage stemming from the P&C of shading devices. It was concluded that in energy design, in addition to OE, P&C energy should be evaluated. In environmental design, due to a major reduction in the OE saving benefit, the importance of the P&C environmental damage increased. Environmental design cannot be replaced with energy design when PV energy generation is assumed for building OE needs.