The global energy system is undergoing a major transition, and in energy planning and decision-making across governments, industry and academia, models play a crucial role. Because of their policy relevance and contested nature, the transparency and open availability of energy models and data are of particular importance. Here we provide a practical how-to guide based on the collective experience of members of the Open Energy Modelling Initiative (Openmod). We discuss key steps to consider when opening code and data, including determining intellectual property ownership, choosing a licence and appropriate modelling languages, distributing code and data, and providing support and building communities. After illustrating these decisions with examples and lessons learned from the community, we conclude that even though individual researchers' choices are important, institutional changes are still also necessary for more openness and transparency in energy research

Energy system models have become indispensable tools for planning future energy systems by providing insights into different development trajectories. However, sustainable systems with high shares of renewable energy are characterized by growing cross-sectoral interdependencies and decentralized structures. To capture important properties of increasingly complex energy systems, sophisticated and flexible modelling tools are needed. At the same time, open science is becoming increasingly important in energy system modelling. This paper presents the Open Energy Modelling Framework (oemof) as a novel approach to energy system modelling, representation and analysis. The framework provides a toolbox to construct comprehensive energy system models and has been published open source under a free licence. Through collaborative development based on open processes, the framework supports a maximum level of participation, transparency and open science principles in energy system modelling. Based on a generic graph-based description of energy systems, it is well-suited to flexibly model complex cross-sectoral systems and incorporate various modelling approaches. This makes the framework a multi-purpose modelling environment for modelling and analyzing different systems at scales ranging from urban to transnational.

The mitigation of climate change demands a decarbonisation of the energy supply of industrialized countries by 2050. This requires fundamental changes of the energy system, high efficiency improvements and a transition to 100% renewable energy supply. A successful transition will need an extremely high acceptance of the general public to be achieved in the given time frame. The necessity of new production, transmission and storage facilities can only by analyzed by highly complex analytical models, which usually are proprietary. In general it is not transparent how the results are derived. To increase the public trust in the results of the underlying modeling, the University of Flensburg is developing the open source model renpass (renewable energy pathways simulation system), for the techno‐economic simulation of the future development of the German and European electricity system. This model is supposed to be made available to the general public to scrutinize the assumptions and results of the planning process for the German ‘Energiewende,’ the transition to a 100% renewable electricity supply. The open source energy model has the goal to fulfill the requirements of full transparency and the possibility to image 100% renewable energy target systems as well as today's system and all stages of the system transition on a high regional and time resolution basis. The data input, the simulation as well as the optimization and the output are described. In the end the application possibilities especially for the ‘Energiewende’ in Germany are described and an outlook on future development is given. WIREs Energy Environ 2014, 3:490–504. doi: 10.1002/wene.109 This article is categorized under: Energy Infrastructure > Systems and Infrastructure Energy Policy and Planning > Systems and Infrastructure Energy and Development > Economics and Policy Energy and Development > Systems and Infrastructure

Energy system models have become indispensable to shape future energy systems by providing insights into different trajectories. However, sustainable systems with high shares of renewable energy are characterised by growing crosssectoral interdependencies and decentralised structures. To capture important properties of increasingly complex energy systems, sophisticated and flexible modelling environments are needed. This paper presents the Open Energy Modelling Framework (oemof) as a novel approach in energy system modelling, representation and analysis. The framework forms a structured set of tools and sub-frameworks to construct comprehensive energy system models and has been published open source under a free licence. Using a collaborative development approach and extensive documentation on different levels, the framework seeks for a maximum level of transparency. Based on a generic graph based description of energy systems it is well suited to flexibly model complex crosssectoral systems ranging from a distributed or urban to a transnational scale.This makes the framework a multi-purpose modelling environment for strategic planning of future energy systems.

No abstract