Mastertheis Ana Gonzalez Quintairos SENDEDVERSION
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Technische Universität Berlin Master Thesis Analysis of potential distribution and size of photovoltaic systems on rural rooftops A contribution to an optimized local energy storage system with a remote sensing and GIS-based approach in Swabia, Germany A thesis submitted in fulfilment of the requirements for the degree of Master of Science Environmental Planning by Ana González Quintairos Matriculation number: 349833 First Supervisor: Prof. Dr. Kleinschmit Second Supervisor: Dr. Jochen Bühler Faculty VI Planning-Building-Environment Geoinformation in Enviromental Planning January 2015 In cooperation with Reiner Lemoine Institut gGmbH Abstract Abstract This work studies the distribution of photovoltaic systems in rural areas. The aim of the study is to create a method which predicts the size and location of future photovoltaic systems on rooftops. Only very few authors have also attempted to use high-resolution images to quantify the suitable rooftop surface per building and the appropriated loca- tion of the panels and none of them have addressed the particular building distribution and typology of rural communities. Addressing rural areas has a tremendous importance in Germany where highest PV potential in Germany is expected. The methodology uses as inputs high-resolution aerial imagery, GIS building footprint from the Land-register map and the Bavarian database of photovoltaic systems. The method has been applied to the village of Freihalden (Bavaria) using two different type of images: official orthophotos from the Bavarian Land-survey Office and Google Earth™ orthophotos and the results on rooftop suitable area and on rooftop potential for PV have been compared with each other. The study area is located in Freihalden, Bavaria. First, the current status quo was analysed, cross-referencing the files from the Bavarian register of photovoltaic systems and the cadastre data. These buildings were excluded from dataset in order to avoid assigning them as potential building for PV in the future. To calculate the spatial distributed potential of the installed photovoltaic power on roof- tops in the future, a pixel-based image analysis is performed on each image to identify suitable rooftop areas, roof obstructions and shadows. The output of the image classifica- tion analysis is converted to vector data and the potential suit-able area is assigned to each building. Rooftop orientation and average slope are spatially joined to each rooftop. The results together with the location in coordinates of each building are giving as input to the PV Calculator, developed by the RLI, to obtain the potential annual energy pro- duction of each building. Finally, the prognosis step predicts the likely PV-expansion pathway based on each rooftop PV potential and the scenarios of the German Energy Agency. The output of the method is stored in a database including the central coordi- nates of each building. Freihalden was found to have 43 buildings with already PV systems in its rooftops which represented an already installed nominal power of 571 kWp. The classification of the Ba- varian land-register orthophoto concluded that 82% of the buildings in the community have adequate areas with more than 10 m2 suitable for PV, where as in the classification of the Google Earth™ orthophoto 78% of the buildings are considered to have adequate i Abstract areas for PV. In average 39% of total rooftop area is considered suitable for PV. This number can be used a rule-of-thumb for future studies in the area. The total PV tech- nical potential of Freihalden reaches the 3170 kWp. Individual building potential ranges from 1 potential kWp to 42 kWp and the specific yield varies from 980,1 to 763,1 kWp/kWh. From the 412 buildings composing the village, 98 will be required to installed new PV systems if the municipality has to fulfil its share on the Bavarian renewable en- ergy goals for 2030. The comparison shows that both airborne high-resolution orthophoto and high-resolution Google Earth™ are capable of delivering trustworthy results with 11% and 16% error respectably using open-source software. The method developed in this study has been further used to estimate the PV potential and prognosis expansion pathway of two more municipalities in Bavaria supporting the research of the project Smart-Power-Flow at the Reiner Lemoine Institute. ii Table of contents Table of contents Abstract ......................................................................................................... i Table of contents ............................................................................................................ iii List of figures ................................................................................................................. iv List of tables ................................................................................................................... vi List of maps .................................................................................................................... vi Abbreviations ................................................................................................................ vii Chapter 1 Introduction ............................................................................... 1 1.1 Background ............................................................................................................. 1 1.2 Context and objectives ........................................................................................... 2 1.3 Structure of the thesis ............................................................................................ 3 Chapter 2 State of the art .......................................................................... 4 2.1 Suitable rooftop area .............................................................................................. 4 2.1.1 Constant-value methods ............................................................................ 5 2.1.2 Remote sensing methods ........................................................................... 6 2.1.3 3D/LiDAR methods .................................................................................. 7 2.2 Global solar radiation ............................................................................................. 8 2.3 PV energy production ........................................................................................... 10 2.4 Data availability ................................................................................................... 13 2.5 Research approach and research questions ........................................................... 16 Chapter 3 Methods .................................................................................... 17 3.1 Description of the study area ................................................................................ 17 3.2 Input data ............................................................................................................. 19 3.2.1 General cartography ................................................................................ 19 3.2.2 Land register map ................................................................................... 20 3.2.3 Official orthophotos from BVW .............................................................. 21 3.2.4 Google Earth orthophotos ....................................................................... 22 3.2.5 Bavarian photovoltaic database .............................................................. 23 3.2.6 Statistics per municipality ...................................................................... 23 3.3 Research design ..................................................................................................... 23 3.3.1 Data preparation ..................................................................................... 25 3.3.2 Isolating building rooftops ...................................................................... 28 iii 3.3.3 Analysis of status quo ............................................................................. 28 3.3.4 Pixel-based classification ......................................................................... 29 3.3.5 Computation of total suitable area ......................................................... 34 3.3.6 PV energy production ............................................................................. 35 3.3.7 Validation ................................................................................................ 36 3.3.8 Prognosis of the most probable locations for PV systems ....................... 37 Chapter 4 Results ...................................................................................... 40 4.1 Status quo ............................................................................................................. 40 4.2 Suitable area computation .................................................................................... 42 4.2.1 Bavarian land-register orthophoto ........................................................... 43 4.2.2 Google Earth images ............................................................................... 44 4.3 PV technical potential .......................................................................................... 46 4.3.1 Bavarian land-register orthophoto ........................................................... 46 4.3.2 Google Earth images ............................................................................... 47 4.4 PV prognosis expansion