Python for Power System Analysis (PyPSA) is a free software toolbox for simulating and optimising modern power systems that include features such as conventional generators with unit commitment, variable wind and solar generation, storage units, sector coupling and mixed alternating and direct current networks. PyPSA is designed to scale well with large networks and long time series. Find out more at: https://pypsa.org/ and http://github.com/FRESNA/PyPSA This is release 0.13.0 of PyPSA. Hyperlinked release notes can be found here: https://www.pypsa.org/doc/release_notes.html#pypsa-0-13-0-25th-january-2018 This release contains new features aimed at coupling power networks to other energy sectors, fixes for library dependencies and some minor internal API changes. * If you want to define your own components and override the standard functionality of PyPSA, you can now override the standard components by passing pypsa.Network() the arguments override_components and override_component_attrs, see the section on Custom Components. There are examples for defining new components in the git repository in examples/new_components/, including an example of overriding network.lopf() for functionality for combined-heat-and-power (CHP) plants. * The Link component can now be defined with multiple outputs in fixed ratio to the power in the single input by defining new columns bus2, bus3, etc. (bus followed by an integer) in network.links along with associated columns for the efficiencies efficiency2, efficiency3, etc. The different outputs are then proportional to the input according to the efficiency; see sections Link with multiple outputs or inputs and Controllable branch flows: links and the example of a CHP with a fixed power-heat ratio. * Networks can now be exported to and imported from netCDF files with network.export_to_netcdf() and network.import_from_netcdf(). This is faster than using CSV files and the files take up less space. Import and export with HDF5 files, introduced in PyPSA 0.12.0, is now deprecated. * The export and import code has been refactored to be more general and abstract. This does not affect the API. * The internally-used sets such as pypsa.components.all_components and pypsa.one_port_components have been moved from pypsa.components to network, i.e. network.all_components and network.one_port_components, since these sets may change from network to network. * For linear power flow, PyPSA now pre-calculates the effective per unit reactance x_pu_eff for AC lines to take account of the transformer tap ratio, rather than doing it on the fly; this makes some code faster, particularly the kirchhoff formulation of the LOPF. * PyPSA is now compatible with networkx 2.0 and 2.1. * PyPSA now requires Pyomo version greater than 5.3. * PyPSA now uses the Travis CI continuous integration service to test every commit in the PyPSA GitHub repository. This will allow us to catch library dependency issues faster. We thank Russell Smith of Edison Energy for the pull request for the effective reactance that sped up the LOPF code and Tom Edwards for pointing out the Pyomo version dependency issue. For this release we also acknowledge funding to Tom Brown from the RE-InVEST project.

{"references": ["https://arxiv.org/abs/1707.09913"]}