Open letter calling for CC-BY-4.0 licenses on structured information describing energy systems


To the extent possible under law, Robbie Morrison and Maximilian Parzen have waived all copyright and related or neighboring rights to this letter. This work is published from Germany.

Open energy system modelers call for CC‑BY‑4.0 data licensing wherever possible — our world needs comprehensive usable and reusable data to transition to net‑zero

18 January 2023
Release 05

To whom it may concern


This open letter is directed toward organizations that variously collect, generate, collate, curate, revise, package, summarize, catalog, and publish or republish structured information describing energy systems — with a particular focus on those datasets suitable for integrated system modeling and allied numerical analysis.

Such organizations would include public bodies, multilateral agencies, civil society organizations, universities and research institutes, commercial entities, open source modeling projects, and citizen science projects.

The measures presented are not tied to particular national jurisdictions, although some legal systems offer less natural protection for data than other systems — with the United States and the United Kingdom providing respective examples along the spectrum from lax to strict.


National energy transitions require a sequence of substantial, robust, and timely investment decisions. Good systems planning can therefore assist. It can help allocate or exclude resources, identify the more rapid and feasible pathways, provide cost estimates, and engage the interested public. The modeling software is only part of that story — far more important is good quality systems information.

At present, much of the data needed is either retained, paywalled, public but not licensed for reuse, or offered under bespoke terms which necessarily create legal silos. The upshot is that much of the information needed for independent analysis remains necessarily piecemeal and incomplete and wide‑ranging curation and uptake is prevented because the various terms‑of‑use provided are either too restrictive or legally immiscible.

Moreover, some civil society and public organizations publish their datasets under non‑commercial terms to allow allied data sales. Such terms can be problematic for university researchers in receipt of third‑party funding who may not clearly class as non‑commercial in this context. The associated private data sales also prevent consultancies and corporations from sharing their populated systems models for wider benefit and cooperation.

The relatively easy and proven solution to these problems is open data licensing. This letter asks that the Creative Commons CC‑BY‑4.0 license be applied, wherever possible, to primary data of public interest within the energy domain.

This particular solution mostly requires no funding (although some sales revenues may need compensation), no change in legislation, and no third‑party consent (presuming the data provider generated the requisite information) — just simply a commitment to the ideal of common information and a desire to share and receive. And despite some costs, this solution is likely to provide very substantial benefits to systems analysts and beyond as nations and regions race to decarbonize.

The following section — signed mostly by independent energy systems analysts — fleshes out the details of and rationale for the solution being advocated.

Our requests

We, the undersigned, request that, wherever possible, structured data made public for energy system analysis be licensed using the Creative Commons CC‑BY‑4.0 license. With the accompanying metadata — which captures context, provenance, and legal status — released instead under the Creative Commons CC0‑1.0 public domain waiver to facilitate cataloging and discovery.

Both the aforementioned legal instruments provide for full use and reuse in original or modified form, but CC‑BY‑4.0 additionally requires that attribution be recorded and tracked. Attribution aids provenance and should not be considered a burden for robust and repeatable numerical analysis.

We additionally ask that any overarching formal or informal data standards that apply — which may include vocabularies, ontologies, data models, reference architectures, and database schemas — be placed under any of the Creative Commons open licenses, including CC‑BY‑SA‑4.0, so that the concepts and specifications provided can be applied to both numerical information and system modeling frameworks without the legal risk of less‑open or unlicensed intellectual property rights transferring across to duly informed datasets and codebases.

This letter applies only to material that has been or can be made public — thereby taking personally identifiable information (PII), trade secrets, and other forms of personal and commercial confidential information off the table.

Two fundamental drivers lie behind these recommendations. First, applying such licenses will provide legal certainty to the users and reusers of such data, as the legal status of the information in question is often far from clear. And second, the information so licensed will be widely legally miscible and thus able to contribute to the development of a knowledge commons that spans the energy systems domain.

A user‑led knowledge commons is especially important because systems modelers need and seek coherent and complete structured data. And open data standards can play a key role in ensuring some level of semantic and technical consistency across both models and data.

Other public licenses and waivers that are inbound compatible with CC‑BY‑4.0 are also acceptable — with the proviso that robust independent analysis supports such claims.

More information can be found on the Open Energy Modeling Initiative discussion forum under tag “ccyby2023”:

The signatories to this open letter are attached as a table, together with their institutional affiliations when also provided.

Yours sincerely, the undersigned.

open-energy-modeling-open-data-letter-early-2023.05.pdf (95.6 KB)


To sign, simply click the Edit icon on this posting and add your details. You will need to be registered on this forum. This is a so‑called wiki post.

If you are not registered with this forum and would like to have your name added anyway, please email:

Approximate count: 64


Person Affiliation (optional) Handle (optional)
Robbie Morrison @robbie.morrison
Maximilian Parzen The University of Edinburgh, PyPSA meets Earth @MaxParzen
Luigi Moccia Consiglio Nazionale delle Ricerche, Italy @LuigiMoccia
Koen van Greevenbroek UiT The Arctic University of Norway @koenvg
Davide Fioriti Università di Pisa, PyPSA meets Earth @davidsf
Tom Brown Technische Universität Berlin, PyPSA @tom_brown
Fabian Hofmann Technische Universität Berlin, PyPSA @fabianhofmann
Malte Schäfer Technische Universität Braunschweig
Fabian Neumann Technische Universität Berlin, PyPSA @fabian.neumann
Pierre-Francois Duc Reiner Lemoine Institut @pierre-francois.duc
Taco Niet Simon Fraser University School of Sustainable
Energy Engineering
Christoph Tries Technische Universität Berlin @chrstphtrs
Florian Maurer FH Aachen @fmaurer
Iegor Riepin Technische Universität Berlin, PyPSA @iegor.riepin
Martha Frysztacki Karlsruhe Institut für Technologie, PyPSA @martacki
Philipp Glaum Technische Universität Berlin, PyPSA @philipp.glaum
Tobias Augspurger Forschungszentrum Jülich, @ly0n
Yu-Chi Chang Agora Energiewende @rich_yu-chi_chang
Mirko Schäfer University of Freiburg @mirko.schaefer
Sylvain Quoilin University of Liege @sylvain
Pietro Lubello UCL Energy Institute @plubello
Ekaterina Fedotova PyPSA meets Earth @ekatef
Barton Yi-Chung Chen University of Exeter, Renewable Energy Group @Barton
Dylan McConnell UNSW, Collaboration on Energy & Environmental Markets @dylanjmcconnell
Christoph Schimeczek @schimi
Johannes Hampp Justus Liebig University Giessen, PyPSA @johannes.hampp
Felix Nitsch @felixnitsch
Ulrich Frey @litotes
Bruno Schyska
Jethro Browell University of Glasgow @Jethro
Wolf-Peter Schill DIW Berlin @wschill
Ludwig Hülk Reiner Lemoine Institut @ludwig.huelk
Tobias Finke Kelvin Green GmbH @tobias
Ramiz Qussous INATECH - University of Freiburg @ramizqussous
Albert Solà Vilalta The University of Edinburgh @albert.sola
Martin Kittel DIW Berlin @martin_kittel
Tim Fürmann INATECH - University of Freiburg @TimFuermann
Elisabeth Zeyen Technische Universität Berlin, PyPSA @lisa.zeyen
Alexander Kies Aarhus University, University of KwaZulu-Natal @alexkies
Barry McMullin Dublin City University @bmcm
Nicole Ludwig University of Tübingen @nnludwig
Emil Dimanchev Norwegian University of Science and Technology @dimanchev
Daniel Friedrich University of Edinburgh @Daniel
Jarrad Wright National Renewable Energy Laboratory @jarry7
Aboubakr Achraf El Ghazi @elghazi
Robert Brecha University of Dayton and Climate Analytics, PyPSA, OSeMOSYS
Michael Schulthoff Hamburg University of Technology @MiSchu
Nick Adams @nadams-ei
Jens Schmugge DLR Institute of Networked Energy Systems @jensch
Kristina Nienhaus @KriNiTi
Tyler Ruggles @truggles
Arijit Mukherjee @Arijit
Matthew Deakin Newcastle University @deakinmt
Robert Hinterberger NEW ENERGY Capital Invest GmbH @robertH
Leonhard Hofbauer University College London @leonhard.hofbauer
Fabian Schmid Technische Universität Berlin
Aleksander Grochowicz University of Oslo @aleks-g
Shima Sasanpour DLR Institute of Networked Energy Systems @Shima
Oriol Raventos Morera DLR Institute of Networked Energy Systems @OriolRaventos
Virio Andreyana Technische Universität Berlin, PyPSA @Virio_andreyana
Yannick Werner Technical University of Denmark @yanwe
Beneharo Reveron Baecker Technical University of Munich @Beneharo
Lukas Franken University of Edinburgh, The Alan Turing Institute @lukasfranken
Caspar Schauß Technische Universität Berlin @cpschauss
1 Like

Great initiative! I wanted to edit a minor typo (“provisio”), but it seems only the author can edit.

And talking about openness: I posted this also on Mastodon: Wolf-Peter Schill: "🚨 Open letter calling for open #energy #data lice…" - Mastodon Did I just not find openmod (and also Maximilian / Robbie) on Mastodon, or are you not there yet? And if not: why not? :wink:

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I believe the current spelling is correct, please see wikipedia:

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Oh sorry, then this was just because of my limited command of English. Never mess with a native speaker!

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Below is the Bibtex from Zenodo in case someone likes to cite this:

  author       = {Morrison, Robbie and
                  Parzen, Maximilian},
  title        = {{Open energy system modelers call for CC‑BY‑4.0 
                   data licensing wherever possible — our world needs
                   comprehensive usable and reusable data to
                   transition to net‑zero}},
  month        = jan,
  year         = 2023,
  publisher    = {Zenodo},
  doi          = {10.5281/zenodo.7549853},
  url          = {``}

The zenodo DOI and the download URL are thus:

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The following schematic indicates one way of forming a common information pool with the associated stocks and flows indicated. The diagram is intended as a jumping off point for further discussions.