Length based pipeline efficiency

Major changes:
- change the efficiency of H2 pipelines from a static value (that is somewhat faulty see BR pypsa-meets-earth#1213) to a length based calculation similar to PyPSA-Eur in scripts/add_extra_components.py.

Minor changes:
- override the networks component attributes in scripts/add_extra_components.py and scripts/solve_network.py to accomodate the length based efficiencies.
- add the transmission efficiencies of H2 pipelines to the config.

config.default.yaml

@@ -522,6 +522,14 @@ sector:
   lignite:
     spatial_lignite: false
 
+  # TODO: move this section to a different file
+  # efficiencies for length based link efficiencies. Copied from PyPSA-Eur.
+  transmission_efficiency:
+    H2 pipeline:
+      efficiency_static: 1
+      efficiency_per_1000km: 1 # 0.982
+      compression_per_1000km: 0.018
+
   international_bunkers: false #Whether or not to count the emissions of international aviation and navigation
 
   oil:

scripts/add_extra_components.py

@@ -57,7 +57,7 @@
 import numpy as np
 import pandas as pd
 import pypsa
-from _helpers import configure_logging, create_logger
+from _helpers import configure_logging, create_logger, override_component_attrs
 from add_electricity import (
     _add_missing_carriers_from_costs,
     add_nice_carrier_names,
@@ -261,10 +261,49 @@ def attach_hydrogen_pipelines(n, costs, config):
         p_nom_extendable=True,
         length=h2_links.length.values,
         capital_cost=costs.at["H2 pipeline", "capital_cost"] * h2_links.length,
-        efficiency=costs.at["H2 pipeline", "efficiency"],
         carrier="H2 pipeline",
     )
 
+    # TODO: when using the lossy_bidirectional_links fix, move this line AFTER lossy_bidirectional_links() 
+    # set the pipelines's efficiency
+    set_length_based_efficiency(n, "H2 pipeline", " H2",config)
+
+
+def set_length_based_efficiency(n: pypsa.components.Network, carrier: str, bus_suffix: str, config: dict) -> None:
+
+    '''
+    Set the efficiency of all links of type carrier in network n based on their length and the values specified in the config.
+    Additionally add the length based electricity demand, required for compression (if applicable).
+    '''
+
+    # get the links length based efficiency and required compression
+    efficiencies = config["sector"]["transmission_efficiency"][carrier]
+    efficiency_static = efficiencies.get("efficiency_static", 1)
+    efficiency_per_1000km = efficiencies.get("efficiency_per_1000km", 1)
+    compression_per_1000km = efficiencies.get("compression_per_1000km", 0)
+
+    # indetify all links of type carrier
+    carrier_i = n.links.loc[n.links.carrier == carrier].index
+
+    # set the links' length based efficiency
+    n.links.loc[carrier_i, "efficiency"] = (
+        efficiency_static
+        * efficiency_per_1000km ** (n.links.loc[carrier_i, "length"] / 1e3)
+    )
+
+    # set the links's electricity demand for compression
+    if compression_per_1000km > 0:
+        n.links.loc[carrier_i, "bus2"] = n.links.loc[carrier_i, "bus0"].str.removesuffix(bus_suffix)
+        # TODO: use these lines to set bus 2 instead, once n.buses.location is functional and remove bus_suffix.
+        '''
+        n.links.loc[carrier_i, "bus2"] = n.links.loc[carrier_i, "bus0"].map(
+            n.buses.location
+        )  # electricity
+        '''
+        n.links.loc[carrier_i, "efficiency2"] = (
+            -compression_per_1000km * n.links.loc[carrier_i, "length"] / 1e3 # TODO: change to length_original when using the lossy_bidirectional_links fix
+        )
+
 
 if __name__ == "__main__":
     if "snakemake" not in globals():
@@ -274,7 +313,8 @@ def attach_hydrogen_pipelines(n, costs, config):
 
     configure_logging(snakemake)
 
-    n = pypsa.Network(snakemake.input.network)
+    overrides = override_component_attrs(snakemake.input.overrides)
+    n = pypsa.Network(snakemake.input.network, override_component_attrs=overrides)
     Nyears = n.snapshot_weightings.objective.sum() / 8760.0
     config = snakemake.config
 

scripts/solve_network.py

@@ -986,11 +986,8 @@ def solve_network(n, config, solving={}, opts="", **kwargs):
 
     is_sector_coupled = "sopts" in snakemake.wildcards.keys()
 
-    if is_sector_coupled:
-        overrides = override_component_attrs(snakemake.input.overrides)
-        n = pypsa.Network(snakemake.input.network, override_component_attrs=overrides)
-    else:
-        n = pypsa.Network(snakemake.input.network)
+    overrides = override_component_attrs(snakemake.input.overrides)
+    n = pypsa.Network(snakemake.input.network, override_component_attrs=overrides)
 
     if snakemake.params.augmented_line_connection.get("add_to_snakefile"):
         n.lines.loc[n.lines.index.str.contains("new"), "s_nom_min"] = (