add flow path expansion

dodo.py

@@ -188,6 +188,9 @@ def create_pypsa_inputs_from_config_and_ispypsa_inputs(
     )
     lines_interregional_or_subregional = translate_flow_paths_to_lines(
         ispypsa_inputs_location,
+        config.network.transmission_expansion,
+        config.wacc,
+        config.network.annuitisation_lifetime,
     )
     lines_rez_to_region_or_subregion = (
         translate_renewable_energy_zone_build_limits_to_flow_paths(
@@ -309,6 +312,7 @@ def task_create_ispypsa_inputs():
                 "mapping_nem_region_to_single_sub_region.csv",
             ),
             Path(_ISPYPSA_INPUT_TABLES_DIRECTORY, "flow_paths.csv"),
+            Path(_ISPYPSA_INPUT_TABLES_DIRECTORY, "transmission_expansion_costs.csv"),
             Path(_ISPYPSA_INPUT_TABLES_DIRECTORY, "ecaa_generators.csv"),
             Path(_ISPYPSA_INPUT_TABLES_DIRECTORY, "coal_prices.csv"),
             Path(_ISPYPSA_INPUT_TABLES_DIRECTORY, "gas_prices.csv"),

ispypsa_runs/development/ispypsa_inputs/ispypsa_config.yaml

@@ -13,6 +13,9 @@ scenario: Step Change
 # costs, as a fraction, i.e. 0.07 is 7%.
 wacc: 0.07
 network:
+  # Does the model consider the expansion of sub-region to sub-region transmission
+  # capacity
+  transmission_expansion: True
   # Does the model consider the expansion of renewable energy zone transmission
   # capacity
   rez_transmission_expansion: True

src/ispypsa/config/validators.py

@@ -15,6 +15,7 @@ class NodesConfig(BaseModel):
 class NetworkConfig(BaseModel):
     nodes: NodesConfig
     annuitisation_lifetime: int
+    transmission_expansion: bool
     rez_transmission_expansion: bool
     rez_to_sub_region_transmission_default_limit: float
 

src/ispypsa/templater/manually_extracted_template_tables/6.0/transmission_expansion_costs.csv

@@ -0,0 +1,14 @@
+flow_path_name,indicative_transmission_expansion_cost_$/mw
+CQ-NQ,1.126363636
+CQ-GG,0.838709677
+SQ-CQ,0.513333333
+NNSW-SQ,1.702027027
+Terranora,NA
+CNSW-NNSW,0.497666667
+CNSW-SNW,0.284
+SNSW-CNSW,0.502333333
+VIC-SNSW,2.00554939
+Heywood,0.454333333
+SESA-CSA,0.602333333
+Murraylink,NA
+Basslink,3.646666667

src/ispypsa/translator/lines.py

@@ -2,22 +2,45 @@
 
 import pandas as pd
 
+from ispypsa.translator.helpers import annuitised_investment_costs
 from ispypsa.translator.mappings import _LINE_ATTRIBUTES
 
 
-def translate_flow_paths_to_lines(ispypsa_inputs_path: Path | str) -> pd.DataFrame:
+def translate_flow_paths_to_lines(
+    ispypsa_inputs_path: Path | str,
+    expansion_on: bool,
+    wacc: float,
+    asset_lifetime: int,
+) -> pd.DataFrame:
     """Process network line data into a format aligned with PyPSA inputs.
 
     Args:
         ispypsa_inputs_path: Path to directory containing modelling input template CSVs.
+        expansion_on: bool indicating if transmission line expansion is considered.
+        wacc: float, as fraction, indicating the weighted average coast of capital for
+            transmission line investment, for the purposes of annuitising capital
+            costs.
+        asset_lifetime: int specifying the nominal asset lifetime in years or the
+            purposes of annuitising capital costs.
 
     Returns:
         `pd.DataFrame`: PyPSA style generator attributes in tabular format.
     """
     lines = pd.read_csv(ispypsa_inputs_path / Path("flow_paths.csv"))
+    costs = pd.read_csv(ispypsa_inputs_path / Path("transmission_expansion_costs.csv"))
+    lines = pd.merge(lines, costs, how="left", on="flow_path_name")
+
     lines = lines.loc[:, _LINE_ATTRIBUTES.keys()]
     lines = lines.rename(columns=_LINE_ATTRIBUTES)
     lines = lines.set_index("name", drop=True)
+
+    lines["capital_cost"] = lines["capital_cost"].apply(
+        lambda x: annuitised_investment_costs(x, wacc, asset_lifetime)
+    )
+
+    # not extendable by default
     lines["s_nom_extendable"] = False
-    lines["capital_cost"] = 0.0
+    # If a non-nan capital_cost is given then set to extendable
+    lines.loc[~lines["capital_cost"].isna(), "s_nom_extendable"] = expansion_on
+
     return lines

src/ispypsa/translator/mappings.py

@@ -11,6 +11,7 @@
     "node_from": "bus0",
     "node_to": "bus1",
     "forward_direction_mw_summer_typical": "s_nom",
+    "indicative_transmission_expansion_cost_$/mw": "capital_cost",
     # TODO: implement reverse direction limit
     # "reverse_direction_mw_summer_typical": ""
 }

tests/config/test_pydantic_model_config.py

@@ -22,6 +22,7 @@ def test_valid_config(
             "scenario": scenario,
             "wacc": 0.07,
             "network": {
+                "transmission_expansion": True,
                 "rez_transmission_expansion": True,
                 "annuitisation_lifetime": 30,
                 "nodes": {
@@ -55,6 +56,7 @@ def test_invalid_scenario():
                 "scenario": "BAU",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -88,6 +90,7 @@ def test_invalid_node_granularity():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -121,6 +124,7 @@ def test_invalid_nodes_rezs():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -154,6 +158,7 @@ def test_not_a_directory_parsed_traces_path():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -187,6 +192,7 @@ def test_invalid_parsed_traces_path():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -220,6 +226,7 @@ def test_invalid_end_year():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -253,6 +260,7 @@ def test_invalid_representative_weeks():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -286,6 +294,7 @@ def test_invalid_wacc():
                 "scenario": "Step Change",
                 "wacc": "7%",
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -319,6 +328,7 @@ def test_invalid_annuitisation_lifetime():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": "years",
                     "nodes": {
@@ -344,6 +354,40 @@ def test_invalid_annuitisation_lifetime():
         )
 
 
+def test_invalid_transmission_expansion():
+    with pytest.raises(ValidationError):
+        ModelConfig(
+            **{
+                "ispypsa_run_name": "test",
+                "scenario": "Step Change",
+                "wacc": 0.07,
+                "network": {
+                    "transmission_expansion": "help",
+                    "rez_transmission_expansion": True,
+                    "annuitisation_lifetime": 30,
+                    "nodes": {
+                        "regional_granularity": "sub_regions",
+                        "rezs": "discrete_nodes",
+                    },
+                    "rez_to_sub_region_transmission_default_limit": 1e6,
+                },
+                "temporal": {
+                    "operational_temporal_resolution_min": 30,
+                    "path_to_parsed_traces": "tests/test_traces",
+                    "year_type": "fy",
+                    "start_year": 2025,
+                    "end_year": 2026,
+                    "reference_year_cycle": [2018],
+                    "aggregation": {
+                        "representative_weeks": [0],
+                    },
+                },
+                "solver": "highs",
+                "iasr_workbook_version": "6.0",
+            }
+        )
+
+
 def test_invalid_rez_transmission_expansion():
     with pytest.raises(ValidationError):
         ModelConfig(
@@ -352,6 +396,7 @@ def test_invalid_rez_transmission_expansion():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": "help",
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -385,6 +430,7 @@ def test_invalid_rez_to_sub_region_transmission_default_limit():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {
@@ -418,6 +464,7 @@ def test_invalid_iasr_workbook_version():
                 "scenario": "Step Change",
                 "wacc": 0.07,
                 "network": {
+                    "transmission_expansion": True,
                     "rez_transmission_expansion": True,
                     "annuitisation_lifetime": 30,
                     "nodes": {