Document existing and planned validation

PyPSA-Eur(-Sec) can be validated against historical data about the energy system to see if it reproduces energy balances, energy prices, import/export flows, curtailment, redispatch and various other energy system statistics. Several validations have already been done, and some are planned. The different validations should be collected here, and then added to a new page "Validation" in the documentation for PyPSA-Eur. Since PyPSA-Eur-Sec will be merged into PyPSA-Eur, we include issues affected other energy sectors too.

Existing validation

• PyPSA-Eur paper includes validation of circuit lengths, network topology and matching of load to grid (looking at load shedding)
• @martacki paper validating historical curtailment in German transmission network
• validation of historical redispatch in Germany by ETH Zürich group (in Willem Laumen Master thesis)
• some validation of curtailment in DLR paper by @FabianHofmann and @p-glaum
• validation by Freiburg group by Freddie, Mirko and Anke, for import/export flows and load distribution
• @matteodefelice modelling of European system with ENTSO-E data (no PyPSA-Eur), including price time series where peaks are missed (probably because of missing unit commitment)
• comparison of TYNDP model thermal ratings to PyPSA-Eur defaults shows PyPSA-Eur defaults are close to mean for most large countries

Ongoing and planned validation

• Validation of power system against 2019 - should include electricity price time series with linearised unit commitment, ramping, CO2 certificate price time series from historical, heat-led CHP and updated varied efficiencies of gas plants
• Improved differentiation of vehicle types in transport model in PyPSA-Eur-Sec
• Improved spatial distribution of district heating, particularly in Germany
• Improved development of RE over 2020-2050 (e.g. going from existing power plants to those with higher hub height, smaller generator to rotor ratio and larger size for wind, and axis tracking for PV with lower AC-DC ratio)
• Comparison of network impedances with Core FBMC model, see @fneum Core TSO project
• Redispatch again following SciGRID redispatch example
• Comparison with CORE grid model and OSM from PyPSA-Earth
• TYNDP projects PR from @grecht

Start with the PyPSA-Eur documentation and review the existing validation references and linked issues, especially issue 363 and the PyPSA-Eur-Sec items. Document the existing and planned validations on a new "Validation" page, with links and enough context to distinguish completed work from future comparisons.