• DE | EN
Short Title: Solarenergienutzung im städtebaulichen Kontext (inklusive IEA-Mitarbeit SHC, Task 51)
Running Time: 06/2013 bis 05/2017
Topics: District concepts, Construction of new housing estates, Refurbishment of housing estates, Energy planning for cities, Decentralised energy generation, Solar heat, Solar power, Modelling & simulation
Innovation: Development of a Project Editor for a central 3D model


  • Solar potential analysis of structural changes in existing and new-build districts
  • Tool simultaneously calculates solar hours, shading and solar irradiation
  • Simple deployment in education and training with a quick learning curve
  • Available as a Java-based, open source web application through the “Lernnetz Bauphysik & Architektur” (Building Physics & Architecture Learning Network)

This platform for urban-based solar potential analysis combines simulation tools for calculating solar hours, shading and solar irradiation in a Java-based and platform-independent application. It is freely available as a web application. Standard solar registers document the total irradiation values on roof surfaces of existing buildings and districts but are not suitable for investigating structural changes in existing buildings or new-build districts. Standard CAD tools enable shading studies, but do not quantify the results. However, a range of planning tools are now available that enable more detailed investigations. As part of the “Lernnetz Bauphysik & Architektur” (Building Physics & Architecture Learning Network), a tool has been developed specifically for use in education and training.

Project context

The Solar Potential Analysis – EnOB Lernnetz project was based on the idea of enabling the simple application of simulations for teaching purposes with a minimum of software requirements. The tool is suitable for basic urban planning teaching and for supporting solar potential analyses for planning tasks at the district level. It is primarily aimed at students. Advantageous are the low system requirements, the platform-independent work and the ability to quickly achieve conceptual findings based on the calculations. Good experiences have been made in the context of compact courses, such as summer academies, since the software is quick to learn and a dedicated building editor is available. Exemplary is EnEff:Stadt’s interdisciplinary “Changing City” Summer Academy, which was held in Berlin in 2016.

Depiction of the calculation result for the daily solar hours on the 3D model.

© Bergische Universität Wuppertal, b+tga

Research focus

The urban-based solar potential analysis combines simulation tools for calculating solar hours, shading and solar irradiation in a Java-based and platform-independent application. All calculation tools use a central CAD model and access a common database that provides the additional data required for the calculations. The CAD model is generated in 3D via a Project Editor on the EnOB Lernnetz. The Project Editor is principally designed so that models can be created at different scales. This enables different urban situations, buildings, rooms and structures to be investigated more closely. A possible further development requires the definition of suitable data exchange formats. A number of activities are being conducted in this regard in the “Planning Tools” working group in the Energy in Buildings and Districts research network. Lernnetz has previously used its own data exchange format.

Screenshot of the Project Editor.

© Bergische Universität Wuppertal, b+tga

Milestones and successes

The foundations for the Lernnetz system stem from the German Federal Ministry of Education and Research’s “Multimedia-Based Learning Network Building Physics” eLearning initiative (2001 and 2004). The core work stems from KIT and was developed as part of a doctorate project (Arne Abromeit). Project partners at the time were the departments for building physics at Darmstadt, Karlsruhe, Kassel, Stuttgart and Weimar universities as well as at Biberach University of Applied Sciences. The project’s main objective was to provide example building physics and calculation methods on the Internet in order to be able to use the new possibilities of this medium in teaching. Since 2007, the work within the EnOB research initiative has been funded within various projects. The “Solar energy use in the urban context” project (2015-2017) completed and stabilised the Project Editor as well as the calculation module for the urban-based analyses.

Export of the calculated solar irradiation values for the applied model and the selected location.

© Bergische Universität Wuppertal, b+tga

Application-ready product, tool, software

The tool is aimed at teachers and students. In the current version, the solar hours, shading and solar irradiation can be calculated based on a central 3D model. The current project package can be downloaded under the following link:


The latest version of Java is required to make it work.


Two tutorials show the utilization of the project editor and further give useful tips. The application is explained step by step... (German only)

Tutorial 1 - Introduction

Tutorial 2 - Calculation

Last Update: 9. May 2017

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