  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.
