Save the date: oemof user meeting 2026.02

Our next in-person user meeting will take place in Nordhausen from 11th to 13th of February 2026. It will be hosted by Nordhausen University of Applied Sciences partly parallel to the  9th Regenerative Energy Technology Conference (page in German).

We are posting this save the date already, as the parallel RET.Con also allows to submit contributions to its proceedings. If you wish to do so, please send an abstract (maximum two pages A4) to ret@hs-nordhausen.de. The deadline for abstracts to the RET.Con is the 15th of October. If accepted, full papers will be due at the 15th of January. Registration to the oemof track will be possible later, (as usual) without abstracts and proceedings.

2025.09 Developer Meeting in Berlin: Save the Date 

We just got the feedback that the next oemof meeting will be hosted by Reiner Lemoine Institut from September 15th to 17th at HTW Berlin. Due to the limited room capacity it will come as a developer meeting. Save the date and contribute, if you are interested! (Beginners, in particular first-time contributors, will get guidance, of course.) 

We created a wiki page for the Meeting 2025.09 to work on the agenda. 
 To register, you can either add your name to the linked Wiki page at GitHub, use the registration form, comment this post, or write an email to meetings@oemof.org. 

TESPy version 0.9 released

Version 0.9 of TESPy is available!

A major refactoring of the presolving and solving architecture has been carried out. The changes will allow users to debug models much more efficiently, as it is possible to extract the list of variables and the list of equations that have been presolved as well as those that are finally passed to the numerical solver. In this context, the presolver now further reduces the model size by identifying linear relationships between variables and mapping such variables to a single one. PowerConnections and respective components like Motor, Generator and PowerBus replace the Bus architecture, for example enabling the modelling of single shaft gas turbines, where the generator efficiency will only affect the net shaft power of the gas turbine.

For the full changelog please check out the documentation website: https://tespy.readthedocs.io/.

Also, a new package in context of thermal engineering has been released under the oemof organization: ExerPy. The exergy analysis features of TESPy have been ported to the new package and it will be developed independently in the future to integrate more methods in the context of exergy analysis. ExerPy provides an easy to use API to read and process the results of your TESPy models.

OWEFE: integrated water, energy, food, and environment systems

As developers and users of the oemof software, we’re always interested in efforts that leverage its modular, open-source design for broader, cross-sectoral analyses. A recent paper, OWEFE, open modelling framework for integrated water, energy, food, and environment systems by J. Fleischmann et al. (2024), presents an “integrated-WEFE” layer that extends oemof’s energy system graph to encompass water, energy, food, and environmental systems in one unified model.

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Feisty Friday: omeof.solph v0.6.0

Without any public announcement, we shadow-dropped oemof.solph v0.6.0 last Friday (solph package 0.6.0 at PyPI, solph 0.6.0 changelog at GitHub). As yesterday was a public Holiday in Germany, this was an extra-bold move, breaking the dogma “never release on Fridays” in an extreme way. Seems like it wasn’t extra-stupid: Until now, nobody complained.

We decided to do this, as we believe it to be a rather stable release. We have cool new features (time-series aggregation and new result handling), but we marked them as experimental. The most noticeable change probably is the completely revised and reshaped documentation, which we tried to be more beginner-friendly than ever. Other changes include removal of API wrappers that allowed to still use old class names and keywords. Highlights of the release include:

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Demandlib 0.2.2: VDI and BDEW25

If a rough estimate for energy demands is just good enough, standard load profiles can be handy. To easily generate these kinds of profiles, we have the “demandlib” in the oemof cosmos. This week, we released a new iteration that includes profiles as defined by the VDI (Verband Deutscher Ingeneure, Association of German Engineers) and the updated profiles by the BDEW (Bundesverband der Energie- und Wasserwirtschaft, German Association of Energy and Water Industries).

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2025.02 dev meeting retrospective

At the last developer meeting, in sunny Flensburg, we focused on decision making and drafting for the future development of solph. Here are the main results:

  • There is consensus that we should have common approach of facades or sub-networks. Currently, there are several similar implementations, namely facades in oemof.tabular, nested energy system object (used for cellular approaches, now removed), and node containers (in MTRESS).
  • We worked hands on at the documentation. Improvements will be merged to the v0.6 dev branch. We also have a suggested colour palette to use in examples:
    Lapis Lazuli (#1F567D) , Cambridge blue (#8AA8A1), Pumpkin (#FA8334) , Rose (#FF006E), Icterine (#FFFD77)
  • We drafted a new class Results that will eventually replace the nested dict generated by solph.processing.results().
  • Before thinking about alternative back-ends to Pyomo, we should remove code duplication.
Group picture taken at the balcony of the FH Flensburg building near the habour.

oemof AUA 2025/03 (today)

As announced previously on other channels, we have an “ask us anything” session today. Unfortunately, we currently experience issues with the server that runs our cloud infrastructure, including the calendar. Thus, the link we originally shared is currently unavailable. So, here is a summary:

Job offer: Join Our Open Source Energy Community!

Hey there!

(Update April, 29th: We found somebody for the described position. As nobody of us except our new team member is compensated by the oemof association, we of course still welcome everybody who is willing to contribute. Best ways to do so are probably joining discussions at openmod:oemof and helping to develop and maintain oemof at GitHub.)

Are you a student or do you have a passion for energy systems and programming? If you love diving into Python projects and exploring innovative ways to optimize energy systems, we’d love to have you on board.

What You’ll Do:

  • Discover & Share: Search the web for fresh publications and real-world applications of oemof, our collection of open source tools.
  • Connect & Learn: Chat with users—from scientists to business professionals—to learn how they’re using energy system optimization.
  • Create & Engage: Write fun, engaging blog posts about your discoveries and share them on social media.

What We’re Looking For:

  • A communicative, curious individual who loves talking to people.
  • A motivated explorer who’s excited to learn about the latest in science and tech.
  • Ideally, you already know a bit about oemof—but if not, that’s cool too!
  • Fluent English skills to engage with our community.

What’s in It for You?

  • A chance to work some hours a month.
  • An opportunity to be part of a vibrant, collaborative open source community.
  • A space to develop your communication and technical skills while making a real impact in the world of energy system optimization.

Does this sound like something you want to do? Send us an email at info@oemof.org. Tell us who you are—what your main job is or, if you’re studying, what you’re studying—and let us know if you’ve ever had contact with oemof. We’re totally open to oemof beginners!

We can’t wait to hear from you!

oemof ask us anything: 2025-02-27

After premier of the “oemof consultation hour” we spontaneously decided to have a short AUA (ask us anything) this Thursday at 16:30 CET. We will try to use our own video call infrastructure (at cloud.oemof.org/call/). So, if you have questions, just dial in and get answers live from the 2025.02 developer meeting.