Α generic quantification of the landscape impacts of wind, solar and hydroelectric energy

Stakeholders in the development of renewable energy are often uncertain about whether landscape impacts are a genuine and objective issue or whether they should be attributed to biased NIMBY (not in my back yard) dispositions by the public. This uncertainty eventually conflicts with the development of effective design methods for the mitigation of impacts. The aim of this work is to reduce the uncertainties over the landscape impacts of renewable energy works, meanwhile also laying a better foundation for their mitigation. In this regard we investigate the following research question: Can the extents and the severity of landscape impacts of different types of renewable energy works be generically and objectively quantified and compared? Hydroelectric, wind and solar works were analysed in detail in this regard, utilizing literature and data from realized projects, from global sources. The analysis focuses on three established metrics of landscape impacts that were elected as insightful indicators covering both the spatial and perceptual aspects of impacts: land use, visibility and public perception. Through the investigation of these metrics, it was demonstrated that wind energy works have been, on average, the most impactful to landscapes, per unit energy generation, followed by solar photovoltaic projects and hydroelectric dams, respectively. More broadly, it was concluded that different types of renewable energy works indeed have different generic landscape impacts and therefore require different mitigation approaches. Overall, the impacts and the approaches for their mitigation are highly dependent on: (i) whether the examined infrastructure-type is perceived negatively by the public, within a landscape context, (ii) the spatial extents of its visual impacts and land-use requirements and (iii) the application or not of architectural and landscape studies, in works that are recipient of architectural treatment.