A conceptual framework on the integration of solar energy systems in heritage sites and buildings

The integration between solar energy systems and building components is very critical in sensitive heritage contexts, especially for the protection of the aesthetical appearance and the historical values of the buildings and their preservation and it is not worthy simple to find useful spaces for a perfect integrationas well as the lack of useful spaces. The solar systems can be divided in photovoltaic (PV) and solar thermal (ST) systems. Particularly, Building Integrated Photovoltaics (BIPV) and Building Integrated Solar Thermal (BIST) are PV or ST panels integrated into the building envelope, combining the energy generation with other functions, such as noise, weather protection, thermal insulation, sun shadow and so on. Nowadays, the dynamism of the market permits to design high compatible products that appear like other traditional architecture materials. This situation boosts the integration with heritage sites and BIPV and BIST systems, especially thanks to the use of advanced customization process, low reflecting and special glasses, innovative low-cost treatments. Limited studied analyses the application of these technologies in heritage contexts, due to the presence of architectonic, conservative, and cultural barriers. For this reason, the paper presents a comprehensive review of the current studies on solar energy technologies in heritage sites and buildings, in order to define a common framework for restores, conservators, and energy experts and to facilitate their diffusion and application in heritage contexts, preserving their cultural and natural values as well as reducing primary energy consumption, increasing comfort levels, minimizing environmental impacts, and improving technical quality and economical outlays. Thus, from this conceptual framework, the study provides several operative strategies for industries and academics, in other to encourage their diffusion and application in sensible contexts.