net-zero biofuels trade scenario

[Renato-Rodrigues]

Purpose of this PR

• Add EU net-zero trade scenario for high biomass availability sensitivity.

  • set the switch cm_import_EU either to nzero_bio to enable the scenario with biofuels, synfuels and H2 trade to the EU, or
  • set the switch cm_import_EU either to high_bio to enable the scenario with biofuels trade to the EU.

• Bio-liquids trade assumptions:

  ***   All EU-27 and UKI regions import quantities proportional to their 2050 `FE|Transport|Pass|Aviation + FE|Industry|Chemicals|Liquids` in the reference NPi run.
  ***   Exporting regions: SSA and LAM (half each)
  ***   Import quantities: exponential increase from 0.3 EJ by 2030 (EU-27) to 7.44 EJ by 2050 for Germany. Fixed from 2050 onward.
  PS: 7.44 EJ =~ 8 EJ of biomass primary energy, assuming pebioil.seliqbio.biodiesel eta

• H2 trade assumptions:

  ***   Importing regions: Germany, from 12 TWh by 2030 to 100 TWh/yr by 2050; and EWN, proportional to German values and `FE|Gases` demand by 2050 in the reference NPi run.
  ***   Exporting regions: UK, Norway and Spain (one-third each)
  ***   Trajectory: exponential curve in between 2030 and 2050 and fixed from 2050 onward.

• E-fuels (e-liquids) trade assumptions:

  ***   All EU-27 and UKI regions import quantities proportional to their 2050 `FE|Transport|Pass|Aviation + FE|Industry|Chemicals|Liquids` in the reference NPi run.
  ***   Exporting regions: SSA, LAM and MEA (one-third each)
  ***   Import quantities: exponential increase from 0.6 TWh/yr by 2030 to 50 TWh/yr by 2050 for Germany. Fixed from 2050 onward.

Type of change

• [x] New feature

Checklist:

• [x] My code follows the coding etiquette
• [x] I performed a self-review of my own code
• [x] I explained my changes within the PR, particularly in hard-to-understand areas
• [x] All automated model tests pass (FAIL 0 in the output of make test)
• [x] The changelog CHANGELOG.md has been updated correctly

Further information (optional):

• Test runs are here: WIP: /p/projects/ecemf/REMIND/2040_scenarios/v06_2024_05_14_rev1_SWG/output