prepare_sector_network: reorder buses for dac components

doc/release_notes.rst

@@ -57,6 +57,8 @@ Upcoming Release
 
 * Add the option to customise map projection in plotting config.
 
+* The order of buses (bus0, bus1, ...) for DAC components has changed to meet the convention of the other components. Therefore, `bus0` refers to the electricity bus (input), `bus1` to the heat bus (input), 'bus2' to the CO2 atmosphere bus (input), and `bus3` to the CO2 storage bus (output).
+
 * The rule ``plot_network`` has been split into separate rules for plotting
   electricity, hydrogen and gas networks.
 

scripts/add_electricity.py

@@ -288,7 +288,7 @@ def attach_load(n, regions, load, nuts3_shapes, ua_md_gdp, countries, scaling=1.
 
     ua_md_gdp = pd.read_csv(ua_md_gdp, dtype={"name": "str"}).set_index("name")
 
-    logger.info(f"Load data scaled with scalling factor {scaling}.")
+    logger.info(f"Load data scaled by factor {scaling}.")
     opsd_load *= scaling
 
     nuts3 = gpd.read_file(nuts3_shapes).set_index("index")

scripts/prepare_sector_network.py

@@ -710,27 +710,27 @@ def add_dac(n, costs):
     heat_buses = n.buses.index[n.buses.carrier.isin(heat_carriers)]
     locations = n.buses.location[heat_buses]
 
-    efficiency2 = -(
+    electricity_input = (
         costs.at["direct air capture", "electricity-input"]
         + costs.at["direct air capture", "compression-electricity-input"]
-    )
-    efficiency3 = -(
+    )  # MWh_el / tCO2
+    heat_input = (
         costs.at["direct air capture", "heat-input"]
         - costs.at["direct air capture", "compression-heat-output"]
-    )
+    )  # MWh_th / tCO2
 
     n.madd(
         "Link",
         heat_buses.str.replace(" heat", " DAC"),
-        bus0="co2 atmosphere",
-        bus1=spatial.co2.df.loc[locations, "nodes"].values,
-        bus2=locations.values,
-        bus3=heat_buses,
+        bus0=locations.values,
+        bus1=heat_buses,
+        bus2="co2 atmosphere",
+        bus3=spatial.co2.df.loc[locations, "nodes"].values,
         carrier="DAC",
-        capital_cost=costs.at["direct air capture", "fixed"],
-        efficiency=1.0,
-        efficiency2=efficiency2,
-        efficiency3=efficiency3,
+        capital_cost=costs.at["direct air capture", "fixed"] / electricity_input,
+        efficiency=-heat_input / electricity_input,
+        efficiency2=-1 / electricity_input,
+        efficiency3=1 / electricity_input,
         p_nom_extendable=True,
         lifetime=costs.at["direct air capture", "lifetime"],
     )