Improve hydro inflow / run of river modelling

[fneum]

The per-country totals of energy capacities of the data/bundle/hydro_capacities.csv file were passed to us by direct communication from Alexander Kies as early as 2015 out of the RESTORE 2050 project.

It would be a good idea to revisit energy capacities, maybe using the JRC hydro database: https://github.com/energy-modelling-toolkit/hydro-power-database

See also PECD: https://zenodo.org/record/3929773#.XwLmMBFS8ch

Also: spatially resolved daily river discharge time-series are now available for Europe from CDS as part of the EFAS dataset (https://confluence.ecmwf.int/display/COPSRV/EFAS+available+data).

[matteodefelice]

FYI, I have started using the most recent PECD (that I have reformatted in Parquet here https://zenodo.org/record/5780185#.YeEViZLMKMo) for power system modelling. In my opinion, this is the best option available right now to model hydropower at country level (PECD uses market zones then for some countries there are multiple nodes)