Model-Based Analysis of Urban Energy Systems (on the Basis of a City's Energy Master Plan)

Abstract

AbstractAs half of the world's population live in cities today, the topic of urbanization and urban energy systems shift continuously into society's focus. It has become a common challenge for local governments to provide a so called Plan, outlining a long term vision for the city's energy infrastructure, to which all planners and investors have to adhere. Being a top-down approach, these Master plans are first of all politically motivated documents, which focus on achieving given targets, such as CO2-emission reductions or higher shares of electric mobility. Originating from these targets, a set of milestones and measures is derived, e.g., the implementation of certain green technologies or refurbishments of buildings. The goal of this paper is to elaborate a model, which allows to analyze a Master Plan from a bottom-up perspective and thereby to be able to quantitatively assess the plan with regards to its feasibility, while identifying possible bottlenecks in their implementation. The results can then serve the city planners to adapt their planning in order to avoid unforeseen problems, when putting the plan's measures into practice. The approach pursued in this research is a combination of system dynamics and an agent-based simulation model of the city's energy system, having both a high spatial and temporal granularity. The model is developed with the multi-method modelling tool Anylogic and Geographic Information System (GIS). The city itself is implemented with its existing building and power infrastructure, which is then subject to the planned measures and developments. The core of the model implements on the one hand different energy generation technologies, both fossil fuels and renewables, reaching from big power plants to small local PV-installations on a private household's roof. On the other hand, the heat and electricity consumers are represented through the buildings. The aim of the model is, at first, to provide a support system to analyze the short and long term effects of the Master Plan. Since its measures are usually not planned in detail concerning exact location or timing of the realization, the simulation results can provide references on these specific details. Secondly, the findings are used to identify the impact of single planned measures and their combinations which answers the questions of how, when and where local electricity and heat producers and the energy efficiency measures influence one another and if they have synergetic or competitive effects. Finally, a set of recommendations is derived from the analyses, which can help the city planners to transfer the strategic measures of the Master Plan into operative business.IntroductionThe topic of urbanization and therewith also urban energy systems shift continuously into society's focus because half of the world's population lives in cities today1. Three quarters of the world energy consumption takes place in cities, being the case for 80% of greenhouse gas emissions. Estimations predict the share of population living in cities to rise to 70% in average and up to 85% in industrialized countries until 205O2. These numbers show clearly the growing importance of an urban energy system which is not only effective and efficient but at the same time also adaptable to new technologies.An urban energy system can be described as the combined process of supply and demand of energy services to cover the given needs of a city's population. This process includes the production, transport and storage of resources as well as the actual conversion into the final end use energy, usually heat and electricity. The cities are not only passive energy consumers with all the power plants outside the urban borders but can increasingly be regarded as an opportunity for many energy transformation units supplying energy locally right where it is needed. This distributed energy generations is becoming an important topic for sustainable use of energy. …