Merge pull request #615 from PyPSA/biogas-upgrade-cc

allow carbon capture in biogas upgrading

config/config.default.yaml

@@ -497,6 +497,7 @@ sector:
   gas_distribution_grid_cost_factor: 1.0
   biomass_spatial: false
   biomass_transport: false
+  biogas_upgrading_cc: false
   conventional_generation:
     OCGT: gas
   biomass_to_liquid: false
@@ -778,6 +779,7 @@ plotting:
     fossil gas: '#e05b09'
     natural gas: '#e05b09'
     biogas to gas: '#e36311'
+    biogas to gas CC: '#e51245'
     CCGT: '#a85522'
     CCGT marginal: '#a85522'
     allam: '#B98F76'

doc/configtables/sector.csv

@@ -118,6 +118,7 @@ gas_distribution_grid _cost_factor,,,Multiplier for the investment cost of the g
 ,,,
 biomass_spatial,--,"{true, false}",Add option for resolving biomass demand regionally
 biomass_transport,--,"{true, false}",Add option for transporting solid biomass between nodes
+biogas_upgrading_cc,--,"{true, false}",Add option to capture CO2 from biomass upgrading
 conventional_generation,,,Add a more detailed description of conventional carriers. Any power generation requires the consumption of fuel from nodes representing that fuel.
 biomass_to_liquid,--,"{true, false}",Add option for transforming solid biomass into liquid fuel with the same properties as oil
 biosng,--,"{true, false}",Add option for transforming solid biomass into synthesis gas with the same properties as natural gas

doc/release_notes.rst

@@ -48,6 +48,8 @@ Upcoming Release
 
 * The ``mock_snakemake`` function can now be used with a Snakefile from a different directory using the new ``root_dir`` argument.
 
+* Add option to capture CO2 contained in biogas when upgrading (``sector: biogas_to_gas_cc``).
+
 * Merged option to extend geographical scope to Ukraine and Moldova. These
   countries are excluded by default and is currently constrained to power-sector
   only parts of the workflow. A special config file

scripts/prepare_sector_network.py

@@ -95,12 +95,14 @@ def define_spatial(nodes, options):
         spatial.gas.industry = nodes + " gas for industry"
         spatial.gas.industry_cc = nodes + " gas for industry CC"
         spatial.gas.biogas_to_gas = nodes + " biogas to gas"
+        spatial.gas.biogas_to_gas_cc = nodes + "biogas to gas CC"
     else:
         spatial.gas.nodes = ["EU gas"]
         spatial.gas.locations = ["EU"]
         spatial.gas.biogas = ["EU biogas"]
         spatial.gas.industry = ["gas for industry"]
         spatial.gas.biogas_to_gas = ["EU biogas to gas"]
+        spatial.gas.biogas_to_gas_cc = ["EU biogas to gas CC"]
         if options.get("co2_spatial", options["co2network"]):
             spatial.gas.industry_cc = nodes + " gas for industry CC"
         else:
@@ -2170,12 +2172,42 @@ def add_biomass(n, costs):
         bus1=spatial.gas.nodes,
         bus2="co2 atmosphere",
         carrier="biogas to gas",
-        capital_cost=costs.at["biogas upgrading", "fixed"],
+        capital_cost=costs.at["biogas", "fixed"]
+        + costs.at["biogas upgrading", "fixed"],
         marginal_cost=costs.at["biogas upgrading", "VOM"],
+        efficiency=costs.at["biogas", "efficiency"],
         efficiency2=-costs.at["gas", "CO2 intensity"],
         p_nom_extendable=True,
     )
 
+    if options.get("biogas_upgrading_cc"):
+        # Assuming for costs that the CO2 from upgrading is pure, such as in amine scrubbing. I.e., with and without CC is
+        # equivalent. Adding biomass CHP capture because biogas is often small-scale and decentral so further
+        # from e.g. CO2 grid or buyers. This is a proxy for the added cost for e.g. a raw biogas pipeline to a central upgrading facility
+
+        n.madd(
+            "Link",
+            spatial.gas.biogas_to_gas_cc,
+            bus0=spatial.gas.biogas,
+            bus1=spatial.gas.nodes,
+            bus2="co2 stored",
+            bus3="co2 atmosphere",
+            carrier="biogas to gas CC",
+            capital_cost=costs.at["biogas CC", "fixed"]
+            + costs.at["biogas upgrading", "fixed"]
+            + costs.at["biomass CHP capture", "fixed"]
+            * costs.at["biogas CC", "CO2 stored"],
+            marginal_cost=costs.at["biogas CC", "VOM"]
+            + costs.at["biogas upgrading", "VOM"],
+            efficiency=costs.at["biogas CC", "efficiency"],
+            efficiency2=costs.at["biogas CC", "CO2 stored"]
+            * costs.at["biogas CC", "capture rate"],
+            efficiency3=-costs.at["gas", "CO2 intensity"]
+            - costs.at["biogas CC", "CO2 stored"]
+            * costs.at["biogas CC", "capture rate"],
+            p_nom_extendable=True,
+        )
+
     if options["biomass_transport"]:
         # add biomass transport
         transport_costs = pd.read_csv(