message_ix_models.tools.update_h2_blending.main

message_ix_models.tools.update_h2_blending.main(scen: Scenario) → None[source]

Revise hydrogen-blending constraints.

The revision of the constraints makes changes to three relations.

  1. For relation h2_scrub_limit, two CCS technologies are removed.

    The relation should limit hydrogen share via blending in all non-CCS gas applications to 50%, hence h2_mix has an entry of -.482 tC/kWa * 2 * input, while all other technologies have an entry of .482 tC/kWa * input. Greenfield CCS technologies do not require an entry into the relation, as well as any other technologies which require the “C” for the output e.g. meth_ng or h2_smr. A negative entry from the greenfield-CCS technologies would further reduce the “total” gas. Theoretically, gas_coal should also have an entry, but is not really necessary as this technology is only active in BAU scenarios, when this constraint is not active. bio_gas has a negative entry to ensure that it doesn’t count towards the total used to derive the share. The retro-fit CCS scrubbers require an entry, because the gas used in powerplants to which the retrofits apply, can be used for CCS purposes and this needs to be avoided. Only secondary-level technologies need to be added.

  2. The relation h2mix_direct is removed in favor of #3. This avoids having to add individual technologies at the final-energy level.

  3. The relation gas_mix_lim is used to limit the share of hydrogen blended into the natural-gas network based on total final-energy gas use. Previously, this constraint was only configured for AFR (at 20%). The constraint is carried over to other regions and set at 50% in all regions including AFR.