Does the total system cost include CO2 cost in the model of pypsa-earth?

[Haiping007]

Hi, there is a question raised about the CO2 emission cost from the system:
Does the total system cost include CO2 cost in the model of pypsa-earth?
I added one scenario (for Kenya) without CO2 constraints and the result is a bit out of expectation that geothermal takes the largest share (>80%) instead of fossil fuels (gas and oil only have a small share).
Maybe it is driven by the cost that geothermal has a lower cost than fossil fuels. (So far, I haven't modified the fuel cost and technology cost in the new scenario).
Do you have any comments or suggestions?
Thank you!