Consider ship transport efficiencies and demands

[energyLS]

Currently, shipping demands are accounted as a certain percentage per kilometer of transport. While this makes sense for e.g. Ammonia (as it may be used as ship fuel), this is not the case for steel (as this will certainly not be used as ship fuels).

However, potentially this assumption is valid in principle, since it increases the necessary supply from renewable sources. Still, this needs to be veryfied and potentially the efficiencies adjusted from hydrogen to steel.

[energyLS]

Consider also the option https://github.com/energyLS/shift/blob/dev/config/config.yaml#L236 when tackling this.

[JanTautorus]

@energyLS Steel-IQ uses the following approach:

The calculation is based on the distances between countries (from the worksheet "Distances"), seaborne bulk transportation costs (based on values corresponding with the "through-the-cycle" average values of Baltic Dry Index), as well as costs of loading/unloading, inland transportation and port charges (based on research and analysis of data from public sources and expert inputs)

to calculate specific cost in USD/t for each country pair. Depending on distance of countries and material this varies between 20 - 100 USD/t