Solar Cadastre for Heritage Sites: A Geoinformation Tool for Balancing Energy Potential and Conservation Needs

The commitment of the European Union to achieve climate neutrality by 2050 increases pressures on areas with protected values. Their protected constituents and spatial characteristics may be adversely impacted by placing renewable energy solutions, which requires careful integration of such systems. The quality of heritage sites is essential for maintaining their significance and identity of place. The paper proposes a methodology for incorporating photovoltaic systems in heritage buildings and within heritage settlements while preserving their spatial qualities. This will be achieved within the scope of a solar cadastre, which serves as a framework for assessing, designing, and implementing sustainable energy solutions in the context of heritage conservation. The solar cadastre serves as an interactive geoinformation support for conservators, decision-makers, and investors. It provides digital models assessing solar potential and heritage vulnerability for urban and rural pilot areas. The solar potential model is aggregated using a theoretical potential for solar energy utilisation; technical potential, including physical, technological and regulatory limitations; economic feasibility of placement; and market potential for placement of solar solutions while adhering to all relevant limitations and requirements. The vulnerability model is aggregated from applicable protection regimes for cultural heritage and several models of visibility: from the vicinity of the heritage settlement (silhouette), important observation points (characteristic views and dominants), and public space in the heritage settlement (pedestrian experience). The models are aggregated into an overall visual exposure index. The models of potential and vulnerability allow testing of different solar energy development scenarios in heritage settlement sites, differing by the restrictiveness of development. The scenarios allow us to assess the possible extent of energy interventions on the buildings, including energy refurbishment and solar energy installations, and their impact on heritage, providing the decision-makers with a tool to balance heritage values and energy targets.