use higher lifetime only for existing German gas CHPs (#90)

* use higher lifetime only for existing German gas CHPs

* actually use adjusted lifetime when asset is created

* Revert "disable chps from prepare_sector_network"

This reverts commit ea88245.

* use pivot_table weighted by capacity to determine lifetimes

* remove old comments

* remove unused dropna

* make NA values for existing gas CHPs a config setting

* add changelog note

* use all lower case for config

Author: Micha

CHANGELOG.md

@@ -1,4 +1,6 @@
 # Changelog
+- Longer lifetime (40 years) is only applied to existing gas CHPs, not new ones. Added a new config entry `existing_capacities:fill_value_gas_chp_lifetime`
+- Bugfix: gas CHPs are extendable again
 - Simplified scenarion definition and made `Mix` the default scenario
 - 0.3: workflow is all public now, no longer requires credentials to internal data
 - Allowing myopic optimization until 2050

config/config.de.yaml

@@ -4,7 +4,7 @@
 
 # docs in https://pypsa-eur.readthedocs.io/en/latest/configuration.html#run
 run:
-  prefix: 20250514_dhsubnodes
+  prefix: 20253006_fix_chp_lifetime
   name:
   # - ExPol
   - KN2045_Mix
@@ -70,6 +70,7 @@ scenario:
 existing_capacities:
   grouping_years_power: [1920, 1950, 1955, 1960, 1965, 1970, 1975, 1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2020]
   grouping_years_heat: [1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2019] # heat grouping years >= baseyear will be ignored
+  fill_value_gas_chp_lifetime: 40 # if no explicit lifetime is given use 40 years. The number was chosen s.t. the existing capacities in 2020 match with statistics.
 
 
 # docs in https://pypsa-eur.readthedocs.io/en/latest/configuration.html#countries
@@ -275,8 +276,6 @@ costs:
 
 # docs in https://pypsa-eur.readthedocs.io/en/latest/configuration.html#sector
 sector:
-  chp:
-    enable: false # This should only deactivate the CHPs from prepare_sector_network, not those from add_existing_baseyear
   v2g: false
   solar_thermal: false
   district_heating:

scripts/add_existing_baseyear.py

@@ -510,6 +510,10 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
     chp["lifetime"] = (chp.DateOut - chp["grouping_year"] + 1).fillna(
         snakemake.params.costs["fill_values"]["lifetime"]
     )
+    chp.loc[chp.Fueltype == "gas", "lifetime"] = (
+        chp.DateOut - chp["grouping_year"] + 1
+    ).fillna(snakemake.params.existing_capacities["fill_value_gas_chp_lifetime"])
+
     chp = chp.loc[
         chp.grouping_year + chp.lifetime > baseyear
     ]  # in add_brownfield this is build_year + lifetime <= baseyear
@@ -572,6 +576,12 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
             aggfunc=lambda x: np.average(x, weights=mastr_chp.loc[x.index, "p_nom"]),
         )
 
+        mastr_chp_lifetime = mastr_chp.pivot_table(
+            index=["grouping_year", "Fueltype"],
+            columns="bus",
+            values="lifetime",
+            aggfunc=lambda x: np.average(x, weights=mastr_chp.loc[x.index, "p_nom"]),
+        )
         mastr_chp_p_nom = mastr_chp.pivot_table(
             index=["grouping_year", "Fueltype"],
             columns="bus",
@@ -589,12 +599,13 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
         # add everything as Link
         for grouping_year, generator in mastr_chp_p_nom.index:
             # capacity is the capacity in MW at each node for this
-            p_nom = mastr_chp_p_nom.loc[grouping_year, generator].dropna()
+            p_nom = mastr_chp_p_nom.loc[grouping_year, generator]
             threshold = snakemake.params.existing_capacities["threshold_capacity"]
             p_nom = p_nom[p_nom > threshold]
 
             efficiency_power = mastr_chp_efficiency_power.loc[grouping_year, generator]
             efficiency_heat = mastr_chp_efficiency_heat.loc[grouping_year, generator]
+            lifetime = mastr_chp_lifetime.loc[grouping_year, generator]
 
             for bus in p_nom.index:
                 # check if link already exists and set p_nom_min and efficiency
@@ -636,11 +647,11 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
                         overnight_cost=costs.at[key, "investment"]
                         * costs.at[key, "efficiency"],
                         marginal_cost=costs.at[key, "VOM"],
-                        efficiency=efficiency_power.dropna().loc[bus],
-                        efficiency2=efficiency_heat.dropna().loc[bus],
+                        efficiency=efficiency_power.loc[bus],
+                        efficiency2=efficiency_heat.loc[bus],
                         efficiency3=costs.at[generator, "CO2 intensity"],
                         build_year=grouping_year,
-                        lifetime=costs.at[key, "lifetime"],
+                        lifetime=lifetime.loc[bus],
                     )
                 else:
                     key = "central solid biomass CHP"
@@ -661,7 +672,7 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
                         efficiency=efficiency_power.loc[bus],
                         efficiency2=efficiency_heat.loc[bus],
                         build_year=grouping_year,
-                        lifetime=costs.at[key, "lifetime"],
+                        lifetime=lifetime.loc[bus],
                     )
 
     # CHPs that are not from MaStR
@@ -671,10 +682,17 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
         values="Capacity",
         aggfunc="sum",
     )
+    chp_nodal_lifetime = chp.pivot_table(
+        index=["grouping_year", "Fueltype"],
+        columns="bus",
+        values="lifetime",
+        aggfunc=lambda x: np.average(x, weights=chp.loc[x.index, "Capacity"]),
+    )
     for grouping_year, generator in chp_nodal_p_nom.index:
-        p_nom = chp_nodal_p_nom.loc[grouping_year, generator].dropna()
+        p_nom = chp_nodal_p_nom.loc[grouping_year, generator]
         threshold = snakemake.params.existing_capacities["threshold_capacity"]
         p_nom = p_nom[p_nom > threshold]
+        lifetime = chp_nodal_lifetime.loc[grouping_year, generator]
 
         for bus in p_nom.index:
             # check if link already exists and set p_nom_min and efficiency
@@ -726,7 +744,7 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
                     efficiency2=costs.at[key, "efficiency"] / costs.at[key, "c_b"],
                     efficiency3=costs.at[generator, "CO2 intensity"],
                     build_year=grouping_year,
-                    lifetime=costs.at[key, "lifetime"],
+                    lifetime=lifetime.loc[bus],
                 )
             else:
                 key = "central solid biomass CHP"
@@ -747,7 +765,7 @@ def add_chp_plants(n, grouping_years, costs, baseyear):
                     efficiency=costs.at[key, "efficiency"],
                     efficiency2=costs.at[key, "efficiency-heat"],
                     build_year=grouping_year,
-                    lifetime=costs.at[key, "lifetime"],
+                    lifetime=lifetime.loc[bus],
                 )
 
 
@@ -1085,9 +1103,8 @@ def add_heating_capacities_installed_before_baseyear(
 
         snakemake = mock_snakemake(
             "add_existing_baseyear",
-            configfiles=["config/test/config.dach.yaml"],
-            clusters="5",
-            ll="v1.5",
+            clusters="27",
+            ll="vopt",
             opts="",
             sector_opts="none",
             planning_horizons="2020",

scripts/pypsa-de/modify_cost_data.py

@@ -140,12 +140,6 @@ def carbon_component_fossils(costs, co2_price):
         f"Scaling central water tank storage investment costs to KEA Technikkatalog: {costs.loc['central water tank storage', 'investment'].value} {costs.loc['central water tank storage', 'investment'].unit}."
     )
 
-    # increase central gas CHP lifetime to 40 years
-    costs.at[("central gas CHP", "lifetime"), "value"] = 40
-    logger.info(
-        f"Setting lifetime of central gas CHP to {costs.at[('central gas CHP', 'lifetime'), 'value']} {costs.at[('central gas CHP', 'lifetime'), 'unit']}."
-    )
-
     # decrease Fischer-Tropsch efficiency
     costs.at[("Fischer-Tropsch", "efficiency"), "value"] = (
         1 / costs.at[("Fischer-Tropsch", "hydrogen-input"), "value"]