Transforming the energy system in multi-functional landscapes: Potential of a landscape-based modelling approach

Abstract

One of the most important challenges of our time is the transformation towards a sustainable future. This encompasses the transition the energy system to renewable energy sources. A large part of this involves the reorganisation of the infrastructure system, in which conventional power plants such as coal and nuclear power plants must be replaced by wind power plants and photovoltaic systems. However, the transformation of the energy system is associated with major economic, ecological and social challenges. These include ensuring stable security of supply and enabling a cost-efficient transition. At the same time it is necessary to avoid undesirable side effects for the environment, economy and society. The transformation process has a large spatial component and is accompanied by structural changes to the multi-functional landscapes in which it takes place. Therefore, it is necessary to explicitly consider the complex interactions of the newly emerging energy infrastructure system with the natural and social environment. Due to the long-term nature of energy infrastructures, a proactive, integrated assessment of the possible development paths of the changing system is necessary. Modelling can provide new insights into the transformation process of the energy system and the development of intervention options that have not yet been fully understood in their consequences. This thesis aims to gain a better understanding of the transformation process of power supply infrastructures in multi-functional landscapes using the example of the energy transition in the electricity sector. An emphasis was put on demonstrating the potential of examining energy system transformations from a holistic environmental energy systems perspective. This was achieved through a dynamic landscape-based approach. In addition, the transformation of the energy system was conceptualised as a spatio-temporal process and considered as the result of allocation decisions regarding the placement of wind and solar power plants in the landscape. The first objective of this thesis was to better understand the process of transforming the energy system, and the identification of factors relevant to the security of supply. This included a systematic analysis of the interplay and relative importance of technological, economic, social and political factors that impose spatial or temporal constraints on the transformation process in terms of ensuring security of supply. Of particular interest was whether power demand can be reliably met at all times and whether interventions in the system can counteract the constraints imposed by other factors. The second objective of this thesis was to conduct a systematic analysis of the trade-offs that occur between security of supply and side effects on the social and natural environment. In addition, limiting factors for energy security were assessed, with a particular focus on the availability of land for the construction of wind power plants. This thesis also pursues a methodological objective: the development of a model to simulate the transformation from conventional to renewable power plants in multi-functional energy landscapes to assess its impact on security of supply and side effects and for a dynamic, landscape-based, proactive and integrated assessment of the transformation of the energy infrastructure system. For this purpose, the stylised and landscape-based model ELAN was developed. It simulates a transformation process from conventional to renewable power supply infrastructure elements on a model landscape. The replacement of conventional power plants by wind and solar power plants is considered as a dynamic process resulting from individual allocation decisions on where to build a power plant. It also includes an agent-based decision component in which model regions can make autonomous decisions to influence the allocation process to counteract spatial externalities. ELAN was applied to different landscape scenarios to analyse spatial and temporal dynamics of the transformation process. The findings of this thesis contribute to a better understanding of security of supply and limiting factors for the transformation process. The results show that maintaining security of supply during the transformation process does not depend on a single factor, but on a complex interplay of natural, technological and socio-economic factors, as well as the landscape-structure. The power demand was identified as a main driver of the transformation process. Furthermore, the results revealed that the landscape structure as well as an interplay of spatial and temporal factors can have a strong influence on the availability of land and on security of supply. It was shown that there are three other limiting factors: affordability, accessibility and the velocity of wind power expansion. Using ELAN, it was possible to gain a mechanistic and causal understanding of the investigated transformation processes. A major advantage of the stylised modelling approach was to break down the high system complexity of a real energy transition to simple contexts. The landscape-based approach made it possible to analyse the impacts with regard to the multi-functionality of landscapes. The dynamic approach of simulating the transformation process resulting from the allocation decisions of wind and solar power plants has revealed insights into the transformation of energy systems. Furthermore, it has facilitated the analysis of transient dynamics and the interplay between the energy system and the landscape. The facilitation of strategic infrastructure planning and proactive integrated assessment was realised in this work by applying ELAN to different scenarios. The model was able to describe plausible futures of transforming energy landscapes. These included for example the future distribution of power plants in the model landscape, the potential land consumption, the assessment of the reliability of supply security and the impact on costs, regional welfare and fairness. Using ELAN, a comprehensive understanding of temporal and spatial dynamics of the underlying system was gained. Potential negative economic, social and environmental impacts were also identified