Checklist

• I am using the current master branch or the latest release. Please indicate.
• I am running on an up-to-date pypsa-eur environment. Update via conda env update -f envs/environment.yaml.

Describe the Bug

We currently assume in the config MWh_H2_per_tNH3_electrolysis: 6.5 to get the hydrogen demand based on paper. But it seems like they calculated with the efficiency of electrolysis of 66% which we shouldn't do since we add the hydrogen and not the electricity demand to the model.

I would suggest switching to the values from the technology-data of

Haber-Bosch    hydrogen-input    1.1484    MWh_H2/MWh_NH3    DECHEMA 2017: DECHEMA: Low carbon energy and feedstock for the European chemical industry (https://dechema.de/dechema_media/Downloads/Positionspapiere/Technology_study_Low_carbon_energy_and_feedstock_for_the_European_chemical_industry.pdf), pg. 57.    178 kg_H2 per t_NH3, LHV for both assumed.

which would result in 1.1484 MWh_H2/MWh_NH3 = ~5.95 MWh_H2/t_NH3 with 1 MWh_NH3 = 0.193 t

@fneum Or am I missing something here?