do not cluster conventional gens, fix CO2 limit

config/config.validation.yaml

@@ -24,13 +24,13 @@ scenario:
   ll:  # allowed transmission line volume expansion, can be any float >= 1.0 with a prefix v|c (today) or "copt"
   - v1.0
   clusters:  # number of nodes in Europe, any integer between 37 (1 node per country-zone) and several hundred
-  - 37
+  - "37m"
   # - 128
   # - 256
   # - 512
   # - 1024
   opts: # only relevant for PyPSA-Eur
-  - ''
+  - 'Co2L'
   sector_opts: # this is where the main scenario settings are
   - Co2L0-3H-T-H-B-I-A-solar+p3-dist1
   # to really understand the options here, look in scripts/prepare_sector_network.py
@@ -91,7 +91,7 @@ co2_budget:
 electricity:
   voltages: [220., 300., 380.]
   gaslimit: false # global gas usage limit of X MWh_th
-  co2limit: 1e9
+  co2limit: 1.0e+9
   co2base: 1.487e+9
   agg_p_nom_limits: data/agg_p_nom_minmax.csv
 
@@ -334,7 +334,7 @@ solar_thermal:
 
 # only relevant for foresight = myopic or perfect
 existing_capacities:
-  unit_commitment: true  # if unit commitment (UC) for conventional power plants is used
+  unit_commitment: false  # if unit commitment (UC) for conventional power plants is used
   # UC is only applied to extendable plants if  linearized UC is used
   grouping_years_power: [1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2020, 2025, 2030]
   grouping_years_heat: [1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2019] # these should not extend 2020
@@ -584,7 +584,7 @@ costs:
     battery: 0.
     battery inverter: 0.
   emission_prices: # in currency per tonne emission, only used with the option Ep
-    co2: 0.
+    co2: 25 # TODO: make this dynamic per month
 
 clustering:
   simplify_network: