Welcome

To install you need to get the repository and install. Do:

    git clone https://github.com/znes/renpass.git
    pip install renpass

To test, run the example with the commandline tool renpass:

    cd renpass/renpass
    renpass examples/investment/datapackage.json

Getting help:

    renpass -h

Example usage with another solver (standard is CBC and with indiviual start and end timestep:

    renpass -o gurobi --t_start 0 --t_end 24 path/to/datapackage.json

Per default, all result files are written back into the sub-folder /results.

Background

Energy systems modelling requires versatile tools to model systems with different levels of accuracy and detail resulting in the complexity of the model. For example, for some countries the lack of data may force energy system analysts to apply simplistic approaches. In other cases comprehensive interlinked models may be applied to analyse energy systems and future pathways.

The Open Energy Modelling Framework is based on graph structure at the core. In addition it provides an optimization model generator to construct individual and suitable models. The internal logic, used terminology and software architecture is abstract and rather designed for model developers and experienced modellers.

Oemof users / developers can model energy systems with different degrees of freedom:

1. Modelling based using existing classes
2. Add own classes
3. Add own constraints based on the underlying algebraic modelling library

However, in some cases complexity of this internal logic and full functionality is neither necessary nor suitable for model users. Therefore we provide so called facade classes that provide an energy specific and reduced access to the underlying oemof functionality.

Currently we provide the following facades:

• Dispatchable
• Volatile
• Connection
• Conversion
• Storage
• ExtractionTurbine
• BackpressureTurbine
• Reservoir
• Load

Modelling energy systems based on these classes is straightforward. Parametrization of an energy system can either be done via python scripting or by using the datapackage structure described below. Datapackages can then easily be processed with the command line tool.

Datapackage

To construct a scenario based on the datapackage

1. Add the topology of the energy system based on the components and their exogenous model parameters.
2. Create a python script to construct the energy system and the model from that data or simply use the existing command line tool.
3. Post-process the data (you may use the EnergySystem.to_datapackage()) method to store your results in datapackage. NOTE: This function has not been implemented in oemof yet.

This allows you to simply publish your scenario (input data, assumptions, model and results) altogether in one consistent block based on the datapackage standard.

How to create a Datapackage

We adhere to the frictionless (tabular) datapackage standard. On top of that structure we add our own logic. We require at least two things:

1. A directory named data containing at least one sub-folder called elements (optionally it may contain a directory sequences and hubs. Of course you may add any other directory, data or other information.)
2. A valid meta-data .json file for the datapackage

NOTE: You MUST provide one file with the buses / hubs called bus.csv!

The resulting tree of the datapackage could for example look like this:

  |-- datapackage
      |-- data
          |-- elements
              |-- demand.csv
              |-- generator.csv
              |-- storage.csv
              |-- bus.csv
          |-- sequences
      |-- scripts
      |-- datapackage.json

To simplifiy the process of creating and processing datapackage you may also use the (datapackage-utilities). The datamodel used for creating facades and examples is also based on the datamodel described there.

Elements

We recommend using one tabular data resource (i.e. one csv-file) for each type you want to model. The fields (i.e. column names) match the attribute names specified in the description of the facade classes.

Example for Demand:

name	type	amount	profile	bus
el-demand	demand	2000	demand-profile1	electricity-bus
...	...	...	...	...

Example for Generator:

name	type	capacity	capacity_cost	bus	marginal_cost
gen	generator	null	800	electricity-bus	75
...	...	...	...	...	...

Sequences

A resource stored under /sequences should at leat contain the field timeindex with the following standard format ISO 8601, i.e. YYYY-MM-DDTHH:MM:SS.

Example:

timeindex	demand-profile1	demand-profile2
2016-01-01T00:00	0.1	0.05
2016-01-01T01:00	0.2	0.1

Scripting

Currently the only way to construct a model and compute it is by using the oemof.solph library. As described above, you can simply use the command line tool on your created datapackage. However, you may also use the facades.py module and write your on application.

Just read the .json file to create an solph.EnergySystem object from the datapackage. Based on this you can create the model, compute it and process the results.

    from oemof.solph import EnergySystem, Model
    from renpass.facades import Load, Dispatchable, Bus

    es = EnergySystem.from_datapackage(
        'datapackage.json',
        attributemap={
            Demand: {"demand-profiles": "profile"}},
        typemap={
            'load': Load,
            'dispatchable': Dispatchable,
            'bus': Bus})

    m = Model(es)
    m.solve()

Note: You may use the attributemap to map your your field names to facade class attributes. In addition you may also use different names for types in your datapackage and map those to the facade classes (use typemap attribute for this)

Write results

Not implemented yet...

Debugging

Debugging can sometimes with tricky, here are some things you might want to consider:

Components do not end up in the model

• Does the data resource (i.e. csv-file) for your components exist in the datapackage.json file.
• Did you set the attributemap and typemap arguments of the EnergySystem.from_datapackge() method of correctly? Make sure all classes with their types are present.

Cast errors when reading a datapackage

• Does the column order match the order of fields in the (tabular) data resource?
• Does the type match the types in of the columns (i.e. for integer, obviously only integer values should be in the respective column)

oemof related errors If you encounter errors from oemof, the objects are not instantiated correctly which may happen if something of the following is wrong in your metadata file:

• foreign-keys Errors regarding the non-int type like this one:

  ...
  self.flows[o, i].nominal_value)
  TypeError: can't multiply sequence by non-int of type 'float'

Check your type(s) in the datapackage.json file. If meta-data are inferred types might be string instead of number or integer which most likely causes such an error.

pyomo related errors

If you encounter an error for writing a lp-file, you might want to check if your foreign-keys are set correctly. In particular for resources with fk's for sequences. If this is missing, you will get unsupported operation string and numeric. This will unfortunately only be happen on the pyomo level currently.

Other ressources

• Preceding project renpass.

Related publications

Boysen, C., Grotlüschen, H., Großer, H., Kaldemeyer, C., and Tuschy, I. (2017). Druckluftspeicherkraftwerk Schleswig-Holstein - Untersuchung zur Eignung Schleswig-Holsteins als Modellstandort für die Energiewende. Nr. 5 der Reihe Forschungsergebnisse des ZNES Flensburg (elektronisch: ISSN 2196-7164 / Print: ISSN 2195-4925)

Mueller, U. P., Wienholt, L., Kleinhans, D., Cussmann, I., Bunke, W.-D., Pleßmann, G. and Wendiggensen, J. (2018) 'The eGo grid model: An open source approach towards a model of German high and extra-high voltage power grids'. Journal of Physics: Conference Series, 977(1), article id. 012003, doi: 10.1088/1742-6596/977/1/012003

Becker, L., Bunke, W., Christ, M., Degel, M., Grünert, J., Söthe, M., Wiese, F. and Wingenbach, C. (2016). VerNetzen: Sozial-ökologische und technisch-ökonomische Modellierung von Entwicklungspfaden der Energiewende. Nr. 4 der Reihe Forschungsergebnisse des ZNES Flensburg (elektronisch: ISSN 2196-7164)

Berg, M., Bohm, S., Fink, T., Hauser, M., Komendantova, N. and Soukup, O. (2016). 'Scenario development and multi-criteria analysis for Morocco’s future electricity system in 2050. Summary of workshop results.' Elaboration et évaluation des différents scénarios du mix électrique futur du Maroc, 23-24 May 2016, Rabat, Morocco.