  DIETER is an open-source power sector model designed to analyze future
settings with very high shares of variable renewable energy sources. It
minimizes overall system costs, including fixed and variable costs of various
generation, flexibility and sector coupling options. Here we introduce DIETERpy
that builds on the existing model version, written in the General Algebraic
Modeling System (GAMS), and enhances it with a Python framework. This combines
the flexibility of Python regarding pre- and post-processing of data with a
straightforward algebraic formulation in GAMS and the use of efficient solvers.
DIETERpy also offers a browser-based graphical user interface. The new
framework is designed to be easily accessible as it enables users to run the
model, alter its configuration, and define numerous scenarios without a deeper
knowledge of GAMS. Code, data, and manuals are available in public repositories
under permissive licenses for transparency and reproducibility.
