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A multi-scale energy systems (MUSES) modeling framework


Calliope is a framework to develop energy system models using a modern and open source Python-based toolchain. It is under active development and freely available under the Apache 2.0 license.

Latest stable release: on PyPI badge_pypi and GitHub badge_githubrelease.



Statue of Calliope; in the Museo Pio-Clementino, Vatican. © Trustees of the British Museum.

Calliope is a framework to develop energy system models, with a focus on flexibility, high spatial and temporal resolution, the ability to execute many runs based on the same base model, and a clear separation of framework (code) and model (data).

A model based on Calliope consists of a collection of text files (in YAML and CSV formats) that define the technologies, locations and resource potentials. Calliope takes these files, constructs an optimization problem, solves it, and reports results in the form of Pandas data structures for easy analysis with Calliope’s built-in tools or the standard Python data analysis stack.

See the introduction section of the documentation and the tutorial for more details.

Calliope’s main features include:

  • Generic technology definition allows modeling any mix of production, storage and consumption
  • Resolved in space: define locations with individual resource potentials
  • Resolved in time: read time series with arbitrary resolution
  • Model specification in an easy-to-read and machine-processable YAML format
  • Able to run on computing clusters
  • Easily extensible in a modular way: custom constraint generator functions and custom time mask functions
  • Uses a state-of-the-art Python toolchain based on Pyomo and Pandas
  • Freely available under the Apache 2.0 license

Comments, bug reports, pull requests, and any other contributions are welcome. See below (Publications) for contact information.

Citing Calliope

Please cite the following paper if you use Calliope for academic research:

Stefan Pfenninger and James Keirstead. 2015. Renewables, nuclear, or fossil fuels? Scenarios for Great Britain’s power system considering costs, emissions and energy security. Applied Energy, 152, pp. 83–93. doi: 10.1016/j.apenergy.2015.04.102

All Calliope releases are archived on Zenodo and you can also refer to specific versions of Calliope with their Zenodo DOI. The most recent archived version is: link-latest-doi


The following publications make use of Calliope-based models:

Pfenninger, Stefan and James Keirstead (2015). Comparing concentrating solar and nuclear power as baseload providers using the example of South Africa. Energy. doi: 10.1016/

Pfenninger, Stefan and James Keirstead (2015). Renewables, nuclear, or fossil fuels? Comparing scenarios for the Great Britain electricity system. Applied Energy, 152, pp. 83-93. doi: 10.1016/j.apenergy.2015.04.102