Fix overlapping bus regions when alternative clustering is selected

doc/release_notes.rst

@@ -18,6 +18,7 @@ This part of documentation collects descriptive release notes to capture the mai
 
 * Prevent computation of powerplantmatching if replace option is selected for custom_powerplants `PR #1281 <https://github.com/pypsa-meets-earth/pypsa-earth/pull/1281>`__
 
+* Fix overlapping bus regions when alternative clustering is selected `PR #1287 <https://github.com/pypsa-meets-earth/pypsa-earth/pull/1287>`__
 
 PyPSA-Earth 0.6.0
 =================

scripts/build_bus_regions.py

@@ -256,6 +256,26 @@ def get_gadm_shape(
         crs=country_shapes.crs,
     ).dropna(axis="index", subset=["geometry"])
 
+    if snakemake.params.alternative_clustering:
+        # determine isolated buses
+        n.determine_network_topology()
+        non_isolated_buses = n.buses.duplicated(subset=["sub_network"], keep=False)
+        isolated_buses = n.buses[~non_isolated_buses].index
+        non_isolated_regions = onshore_regions[
+            ~onshore_regions.name.isin(isolated_buses)
+        ]
+        isolated_regions = onshore_regions[onshore_regions.name.isin(isolated_buses)]
+
+        # Combine regions while prioritizing non-isolated ones
+        onshore_regions = pd.concat(
+            [non_isolated_regions, isolated_regions]
+        ).drop_duplicates("shape_id", keep="first")
+
+        if len(onshore_regions) < len(gadm_country):
+            logger.warning(
+                f"The number of remaining of buses are less than the number of administrative clusters suggested!"
+            )
+
     onshore_regions = pd.concat([onshore_regions], ignore_index=True).to_file(
         snakemake.output.regions_onshore
     )