Aesthetic impact assessment of solar power plants: An objective and a subjective approach

Solar energy for the production of electric energy is one source of renewable energy which is experiencing most development in recent years. In countries with high solar radiation indices, as is the case of Spain, expectations of installation of large solar power plants are increasing. Most solar power plants are located in rural environments, where the landscape has remained practically unaltered ever since extensive agriculture was introduced. Because of this, one of the most significant environmental impacts of this type of installation is the visual impact derived from the alteration of the landscape. In this work, an indicator is proposed for the quantification of the objective aesthetic impact, based on four criteria: visibility, colour, fractality and concurrence between fixed and mobile panels. The relative importance of each variable and the corresponding value functions are calculated using expert contribution. A study of the subjective aesthetic impact is then carried out using the semantic differential method, to obtain the perception of a sample of individuals of the initial landscapes and of the landscapes altered through the installation of a solar power plant. The indicator and the study of public perception are applied to five real solar power plants, to test their reliability. Subsequently, a different group of individuals is used to determine preferences between the five solar power plants. The study proves that the combined use of objective indicator and subjective study, faithfully explains user preferences corresponding to the combined comparisons of the five cases. It is concluded that the tools proposed for the evaluation of the aesthetic impact of solar power plants are useful for the selection of optimal plant location and most adequate use of panel technology, to minimise aesthetic impact.