Solar Photovoltaic Optimal Tilt Angles in Public Building

The reduction of the consumption of fossil fuels that cause climate change and the encouragement of the use of cleaner renewable sources, appears to be a fundamental objective for achieving the climate aims agreed in Paris. Moreover, the sustainability of the implementation of solutions for energy efficiency in public administration buildings has played a fundamental role in recent years, strengthened also by the regulatory context of energy and environmental policies of European countries. The research fits into this context and it intends to promote a methodology that is able to evaluate the economic and environmental performance of a photovoltaic system applied in a school located in Italy when only the roof inclination angle changes. The economic and environmental performances are evaluated respectively through Life Cycle Cost Analysis and the avoided CO₂ emissions. The results show that although the case study does not present the optimal roof inclination angle, there are economic and environmental advantages. Furthermore, the research notes that, considering the characteristics of the photovoltaic system concerned, the optimal roof inclination angle is equal to 40 degrees from an economic and environmental point of view. This methodology could easily support the decision-making process of designers and administrators to make the energy upgrading choices for the promotion of renewable sources. It was applied to a case study, that is a school located in Italy, in the Abruzzo region, in the province of L’Aquila, but it could be easily replicated in other existing public buildings in different locations.