We have a release candidate for v0.5.1 (Package at PyPI, Tag at GitHub). There are some additions, but we also prepare for significant API changes that will come obligatory with v0.6. When upgrading from v0.5.0 to v0.5.1, there should be no changes required for you code. (This is not true if you use features that are explicitly marked “experimental”. Those may change without notice.)

Noticeable changes include:

• The component Transformer is now named Converter.
• You can now combine Investment and OffsetConverter.
• Having energy stored in a GenericStorage can now have a cost.
• You can now give an Investment object as the nominal_value. We considered this more intuitive than working with two mutually exclusive different keyword arguments.
• Tons of improvements in the (still experimental) MultiPeriod optimisation.

Again, there are transitional wrappers, so nothing should break when updating from v0.5.0, using the new API should be voluntary (you get a warning) for now. It would be nice if you test if your solph v0.5 code still works with this RC. We are aiming for a final release of v0.5.1 by the end of August.

We are happy to announce oemof.solph v0.5.0 (codename “Rigorous refactoring”) . This release brings an extreme shift towards more user focused design:

• Clean definition of time indexes: You need N+1 points in time do define N time spans.
• Parts of the energy system graph are now clearly structured into buses, components, and flows. This adds some extra words to imports but makes the underlying logic more transparent.
• Public and private API are be more distinguished now. (‘_’ signifies private, public API is defined in init files.)
• Experimental code is now sitting in sub-modules called experimental (replaces “custom”).
• The flow arguments summed_minand summed_max now have the more descriptive names full_load_time_min and full_load_time_max.
• Keyword arguments are now explicit. This will make it easier to find the correct arguments and will also catch typos. Custom attributes can be added using the argument custom_attributes. Those will be passed down the class hierarchy and can (possibly) be handled in parent classes.
• Add inactivity_costs as an option for Flows. Inactivity costs is a cost for times where a Flow is not operated.
• Examples are added to the documentation. (The format of the examples could be improved, though.)

Besides these changes, there is one big thing that has happened “under the hood”. It is now possible to combine NonConvex and Investment optimisation in the same Flow.