PyPSA · cpschau · Jan 21, 2026 · Jan 27, 2026 · Jan 27, 2026 · Jan 27, 2026
diff --git a/config/config.default.yaml b/config/config.default.yaml
@@ -688,6 +688,12 @@ sector:
     dh_areas:
       buffer: 1000
       handle_missing_countries: fill
+    subnodes:
+      enable: false
+      n_subnodes: 10
+      countries: []
+      demand_column: Dem_GWh
+      label_column: Label
   heat_pump_sources:
     urban central:
     - air

diff --git a/config/schema.json b/config/schema.json
@@ -3921,6 +3921,44 @@
               "additionalProperties": true,
               "description": "District heating areas settings.",
               "type": "object"
+            },
+            "subnodes": {
+              "description": "Configuration for `sector.district_heating.subnodes` settings.",
+              "properties": {
+                "enable": {
+                  "default": false,
+                  "description": "Enable subnodes in district heating sector.",
+                  "type": "boolean"
+                },
+                "n_subnodes": {
+                  "default": 10,
+                  "description": "Number of largest district heating subnodes that are explicitly represented in the network.",
+                  "type": "integer"
+                },
+                "countries": {
+                  "default": [],
+                  "description": "List of country codes to consider for district heating subnodes. If empty, all countries are considered.",
+                  "items": {
+                    "type": "string"
+                  },
+                  "type": "array"
+                },
+                "demand_column": {
+                  "default": "Dem_GWh",
+                  "description": "Name of the column in the single-system level data to use for subnodes.",
+                  "type": "string"
+                },
+                "label_column": {
+                  "default": "Label",
+                  "description": "Name of the column in the single-system level data to use for subnode labels.",
+                  "type": "string"
+              },
+              "use_isi_data_assumptions": {
+                "default": false,
+                "description": "If true, scale subnode demands to match the model's DH demand using ISI data assumptions as denominator.",
+                "type": "boolean"
+              }
+              }
             }
           }
         },
@@ -5966,6 +6004,44 @@
           "additionalProperties": true,
           "description": "District heating areas settings.",
           "type": "object"
+        },
+        "subnodes": {
+          "description": "Configuration for `sector.district_heating.subnodes` settings.",
+          "properties": {
+            "enable": {
+              "default": false,
+              "description": "Enable subnodes in district heating sector.",
+              "type": "boolean"
+            },
+            "n_subnodes": {
+              "default": 10,
+              "description": "Number of largest district heating subnodes that are explicitly represented in the network.",
+              "type": "integer"
+            },
+            "countries": {
+              "default": [],
+              "description": "List of country codes to consider for district heating subnodes. If empty, all countries are considered.",
+              "items": {
+                "type": "string"
+              },
+              "type": "array"
+            },
+            "demand_column": {
+              "default": "Dem_GWh",
+              "description": "Name of the column in the single-system level data to use for subnodes.",
+              "type": "string"
+            },
+            "label_column": {
+              "default": "Label",
+              "description": "Name of the column in the single-system level data to use for subnode labels.",
+              "type": "string"
+            },
+            "use_isi_data_assumptions": {
+              "default": false,
+              "description": "If true, scale subnode demands to match the model's DH demand using ISI data assumptions as denominator.",
+              "type": "boolean"
+            }
+          }
         }
       }
     },
@@ -7483,6 +7559,44 @@
         }
       }
     },
+    "_SubnodesConfig": {
+      "description": "Configuration for `sector.district_heating.subnodes` settings.",
+      "properties": {
+        "enable": {
+          "default": false,
+          "description": "Enable subnodes in district heating sector.",
+          "type": "boolean"
+        },
+        "n_subnodes": {
+          "default": 10,
+          "description": "Number of largest district heating subnodes that are explicitly represented in the network.",
+          "type": "integer"
+        },
+        "countries": {
+          "default": [],
+          "description": "List of country codes to consider for district heating subnodes. If empty, all countries are considered.",
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "demand_column": {
+          "default": "Dem_GWh",
+          "description": "Name of the column in the single-system level data to use for subnodes.",
+          "type": "string"
+        },
+        "label_column": {
+          "default": "Label",
+          "description": "Name of the column in the single-system level data to use for subnode labels.",
+          "type": "string"
+        },
+        "use_isi_data_assumptions": {
+          "default": false,
+          "description": "If true, scale subnode demands to match the model's DH demand using ISI data assumptions as denominator.",
+          "type": "boolean"
+        }
+      }
+    },
     "_TechnologyMappingConfig": {
       "description": "Configuration for `electricity.estimate_renewable_capacities.technology_mapping` settings.",
       "properties": {
@@ -10031,6 +10145,44 @@
               "additionalProperties": true,
               "description": "District heating areas settings.",
               "type": "object"
+            },
+            "subnodes": {
+              "description": "Configuration for `sector.district_heating.subnodes` settings.",
+              "properties": {
+                "enable": {
+                  "default": false,
+                  "description": "Enable subnodes in district heating sector.",
+                  "type": "boolean"
+                },
+                "n_subnodes": {
+                  "default": 10,
+                  "description": "Number of largest district heating subnodes that are explicitly represented in the network.",
+                  "type": "integer"
+                },
+                "countries": {
+                  "default": [],
+                  "description": "List of country codes to consider for district heating subnodes. If empty, all countries are considered.",
+                  "items": {
+                    "type": "string"
+                  },
+                  "type": "array"
+                },
+                "demand_column": {
+                  "default": "Dem_GWh",
+                  "description": "Name of the column in the single-system level data to use for subnodes.",
+                  "type": "string"
+                },
+                "label_column": {
+                  "default": "Label",
+                  "description": "Name of the column in the single-system level data to use for subnode labels.",
+                  "type": "string"
+              },
+              "use_isi_data_assumptions": {
+                "default": false,
+                "description": "If true, scale subnode demands to match the model's DH demand using ISI data assumptions as denominator.",
+                "type": "boolean"
+              }
+              }
             }
           }
         },

diff --git a/config/test/config.overnight.yaml b/config/test/config.overnight.yaml
@@ -74,6 +74,10 @@ sector:
       - 10
       - 21
   district_heating:
+    subnodes:
+      enable: true
+      n_subnodes: 3
+      countries: ['BE']
     ptes:
       supplemental_heating:
         enable: true

diff --git a/data/dh_area_assumptions.csv b/data/dh_area_assumptions.csv
@@ -0,0 +1,26 @@
+country,dh_connection_rate_2020,dh_connection_rate_2050,national_dh_share_2020,national_dh_share_2050,distribution_cost_ceiling_2050_eur_per_MWh,demand_in_dh_areas_2020_GWh,demand_in_dh_areas_2050_GWh,heat_demand_covered_by_dh_2020_GWh,heat_demand_covered_by_dh_2050_GWh,avg_distribution_cost_eur_per_MWh
+AT,0.55,0.8,0.253,0.332,36,38763,19890,21319,15912,28.1
+BE,0.15,0.7,0.034,0.141,34,26027,10636,3904,7445,32.8
+BG,0.64,0.75,0.267,0.349,38,10160,7382,6503,5536,28.7
+CZ,0.44,0.8,0.247,0.43,35,51729,30994,22761,24795,28.1
+DE,0.32,0.75,0.149,0.324,36,375321,171208,120103,128406,33.0
+DK,0.88,0.9,0.528,0.467,40,35273,20287,31040,18259,32.6
+EE,0.58,0.8,0.421,0.522,36,9105,4293,5281,3434,14.3
+EL,0.29,0.7,0.108,0.248,31,14346,11582,4160,8107,29.4
+ES,0.03,0.7,0.014,0.308,36,65881,54311,1976,38018,33.3
+FI,0.63,0.9,0.476,0.63,37,57870,33453,36458,30108,30.5
+FR,0.15,0.75,0.063,0.275,41,203160,123460,30474,92595,33.7
+HR,0.37,0.8,0.113,0.257,32,7702,3614,2850,2892,31.9
+HU,0.33,0.8,0.133,0.325,30,32249,18281,10642,14625,28.2
+IE,0.0,0.7,0.0,0.047,36,1760,1630,0,1141,33.1
+IT,0.17,0.7,0.079,0.31,36,178312,109970,30313,76979,33.8
+LT,0.78,0.9,0.492,0.592,32,10987,6625,8570,5962,15.9
+LU,0.29,0.8,0.195,0.517,32,5266,3066,1527,2453,29.0
+LV,0.57,0.8,0.415,0.599,32,11195,5253,6381,4203,15.9
+NL,0.26,0.75,0.09,0.265,38,46759,28372,12157,21279,35.7
+PL,0.51,0.8,0.272,0.38,31,130002,63942,66301,51153,29.6
+PT,0.33,0.7,0.064,0.139,41,5437,4390,1794,3073,40.5
+RO,0.43,0.75,0.15,0.26,32,29236,14314,12571,10735,29.8
+SE,0.86,0.9,0.663,0.655,42,66416,62989,57118,56690,30.7
+SI,0.52,0.8,0.136,0.192,31,3192,1809,1660,1447,30.7
+SK,0.74,0.9,0.327,0.369,32,13582,6614,10051,5952,29.4
diff --git a/doc/data_inventory.csv b/doc/data_inventory.csv
@@ -41,6 +41,7 @@
 "mobility_profiles","German Vehicle Activity Profiles","Vehicle activity profiles for different vehicle types and road types in Germany, based on monitoring data from the Federal Highway Research Institute (BASt). These profiles provide insights into travel behavior and patterns, which can be used for transport modeling and analysis.","Federal Highway Research Institute (BASt)","https://www.bast.de/DE/Themen/Digitales/HF_1/Massnahmen/verkehrszaehlung/Stundenwerte.html?nn=414410","CC-BY-4.0"
 "dh_areas","","Shapes of district heating areas","ISI Fraunhofer-Institut für System- und Innovationsforschung","https://fordatis.fraunhofer.de/handle/fordatis/341.5","CC-BY-4.0"
 "geothermal_heat_utilisation_potentials","","Potentials for Geothermal heat utilisation","ISI Fraunhofer-Institut für System- und Innovationsforschung","https://fordatis.fraunhofer.de/handle/fordatis/341.5","CC-BY-4.0"
+"geonames_cities","GeoNames cities500","Database of cities with a population > 500, used to map district heating areas to human-readable city names for subnode labelling.","GeoNames","https://download.geonames.org/export/dump/","CC-BY-4.0"
 "jrc_ardeco","Annual Regional Database of the European Commission's Directorate General for Regional and Urban Policy","The database contains a set of long time-series variables and indicators for EU regions, as well as for regions in some EFTA and candidate countries, at various statistical scales (NUTS1, NUTS2, NUTS3, metro regions).","European Commission","https://territorial.ec.europa.eu/ardeco","similar to CC-BY"
 "bidding_zones_electricitymaps","Electricity Maps Bidding Zones","Geospatial data defining bidding zones for electricity markets in Europe","Electricity Maps","https://github.com/electricitymaps/electricitymaps-contrib","AGPL-3.0"
 "bidding_zones_entsoepy","ENTSOE-PY Bidding Zones","Geospatial data defining bidding zones for electricity markets in Europe","EnergieID","https://github.com/EnergieID/entsoe-py","MIT"
diff --git a/doc/release_notes.rst b/doc/release_notes.rst
@@ -9,6 +9,9 @@ Release Notes
 Upcoming Release
 ================
 
+* Added option to model n largest district heating systems (according to demand in #1516) explicitly. Enable via ``sector: district_heating:
+  subnodes: enable: true``.
+
 * Remove snakemake's slurm plugin from windows installations (https://github.com/PyPSA/pypsa-eur/pull/2009).
 
 * Added Xpress solver configuration options (``xpress-default`` and ``xpress-gpu``) with barrier method settings optimized for large-scale linear programming problems.