Aesthetic impact of solar energy systems. Conceptual framework, social perception and european projects involvement

Resumen

The climate change that threatens the current system of life has led to the emergence of new energy policies in recent years, mostly driven by European countries, in order to reduce the consumption of fossil fuels and increase the use of renewable energies. Not in vain, in recent decades there have been significant advances in technologies aimed at energy generation using alternative renewable resources. Large areas of land in the rural environment were used at the beginning of the effective implementation of renewable energy systems. However, in the last 10-15 years their presence is increasing into the buildings, as well as in other spaces in the urban environment. These technologies inevitably cause an intrusion into the landscape and a visual impact that is not always socially accepted, regardless of the type of environment in which they are implemented. The research carried out in this thesis has focused on the aesthetic perception of such facilities, with special attention to the integration of the solar energy systems in cities, as they are the most inhabited places and therefore where the greatest number of people can be affected, as well as on solar energy systems, as they are the most commonly used as shown in our results. Aesthetic perception is a topic widely discussed in the scientific literature; however, the specific aesthetic impact caused by solar energy systems located in the cities is a very recent issue that has scarcely been addressed in previous research. This doctoral dissertation aims to positively contribute preliminary research in this field of study, by establishing an elementary conceptual framework that includes several relevant lines of research. The analysis of the aesthetic impact caused by the installations has an objective and a subjective component. Thus, the first line of research focuses on the objective factors that are most influential, while the second one addresses the subjective perception experienced by the individual. These two lines of research are also necessarily related to each other. Finally, considering the European geographical scope, a third line of research focused on the level of concern of entities that are carrying out the initial phase of promotion and implementation of the systems for this aesthetic impact. Formally, the current thesis is presented as a compendium of two studies previously published in scientific journals of impact (Q1) and a third one pending acceptance for publication. These three studies, taken together, shape our conceptual framework, from which the most relevant results are jointly discussed in a final chapter of conclusions. In the second chapter an in-depth review is made of the existing literature related to the objective factors that influence aesthetic perception, as well as the methods that relate the objective factors to the subjective perception of the impact caused by solar energy systems. This review revealed a total lack of consensus in the previous literature on the most relevant objective factors. Thus, for the first time in the literature, this study establishes –based on previous literature–, that the most influential objective factors in the aesthetic perception of solar energy systems are visibility and integration degree. Additionally, a qualitative methodological framework to assess the aesthetic impact is proposed, in which this impact is divided into 3 sub-impacts: land use, the solar energy system (SES) and glare. In the third chapter, the aesthetic perception from a subjective point of view is addressed. Since no previous research had collected data on the aesthetic perception of the solar energy systems directly from society, a survey was conducted using as a sample scenario the solar housing prototypes from the Solar Decathlon Europe international competition held in Versailles in 2014. In general, we concluded that the perception of buildings with solar energy systems is positive. Prototypes with integrated systems in the enclosure (BIPV) were also found to receive higher ratings in pleasantness compared to those with non-integrated systems housed on the roof (BAPV). The results also revealed, in line with the results of the study in the previous chapter, that the degree to which the observer appreciated the installation influenced his assessment. Finally, the only sociodemographic parameter that turned out to have some influence on the assessment was the age of the respondent, with the youngest people showing the greatest emotional intensity and those who best accepted the more industrially styled BAPV systems. Finally, the fourth chapter analyzes the involvement of European funding programmes with the actual implementation of renewable energy systems, but also the degree of concern of the entities involved with the aesthetic impact generated to society by the projects they develop. To this end, a review was carried out of the 5 European funding programmes most related to the promotion of renewable energies and the mitigation of climate change, including a total of almost 14,000 projects of which only 0.1% were identified as being aimed at implementing a real installation of renewable energies on an urban scale. However, since 2013 there is a growing trend of potential projects with this objective. The most implemented renewable energy system was clearly photovoltaic technology and as for energy storage systems, the most used were lithium batteries. From a geographical point of view, there is a very uneven participation, with Spain and Belgium standing out for their greater involvement, followed by Italy, Germany and France. The H2020 programme was the one that included the most projects that met the requirements of the study. Although this programme has never included the aesthetic impact of these technologies as a key issue, since 2014 the word "aesthetics" has started to appear in the call related to the architectural integration of photovoltaic technology. To conclude the thesis, chapter 5 discusses the results, justifying the fulfilment of the objectives of the thesis and underlining the connection of these results with prior works. It also establishes relations among the various lines of research addressed in the thesis, proposes new lines of future research and analyses the repercussion that this research may have on society, as well as on the process of implementing integrated solar energy systems in the city and the different agents involved in this process: public administration, the solar energy industry, architects and the citizens themselves.