diff --git a/scripts/add_electricity.py b/scripts/add_electricity.py
index bd17dbe5..87516a83 100755
--- a/scripts/add_electricity.py
+++ b/scripts/add_electricity.py
@@ -309,7 +309,7 @@ def attach_conventional_generators(n, costs, ppl, conventional_carriers, extenda
 
     ppl = (ppl.query('carrier in @carriers').join(costs, on='carrier', rsuffix='_r')
            .rename(index=lambda s: 'C' + str(s)))
-    ppl.efficiency.update(ppl.efficiency_r.dropna())
+    ppl["efficiency"] = ppl.efficiency.fillna(ppl.efficiency_r)
 
     logger.info('Adding {} generators with capacities [GW] \n{}'
                 .format(len(ppl), ppl.groupby('carrier').p_nom.sum().div(1e3).round(2)))
diff --git a/scripts/cluster_network.py b/scripts/cluster_network.py
index 642db4da..a3ce5c52 100644
--- a/scripts/cluster_network.py
+++ b/scripts/cluster_network.py
@@ -281,7 +281,9 @@ def clustering_for_n_clusters(n, n_clusters, custom_busmap=False, aggregate_carr
         aggregate_generators_carriers=aggregate_carriers,
         aggregate_one_ports=["Load", "StorageUnit"],
         line_length_factor=line_length_factor,
-        generator_strategies={'p_nom_max': p_nom_max_strategy, 'p_nom_min': pd.Series.sum},
+        generator_strategies={'p_nom_max': p_nom_max_strategy, 'p_nom_min': pd.Series.sum, 
+                              'build_year': lambda x: 0, 'lifetime': lambda x: np.inf, 
+                              'efficiency': np.mean},
         scale_link_capital_costs=False)
 
     if not n.links.empty:
@@ -342,7 +344,7 @@ if __name__ == "__main__":
 
     if snakemake.wildcards.clusters.endswith('m'):
         n_clusters = int(snakemake.wildcards.clusters[:-1])
-        aggregate_carriers = pd.Index(n.generators.carrier.unique()).difference(renewable_carriers)
+        aggregate_carriers = None
     elif snakemake.wildcards.clusters == 'all':
         n_clusters = len(n.buses)
         aggregate_carriers = None # All
diff --git a/scripts/simplify_network.py b/scripts/simplify_network.py
index 287dfe32..5f9aec6c 100644
--- a/scripts/simplify_network.py
+++ b/scripts/simplify_network.py
@@ -200,7 +200,14 @@ def _aggregate_and_move_components(n, busmap, connection_costs_to_bus, output, a
 
     _adjust_capital_costs_using_connection_costs(n, connection_costs_to_bus, output)
 
-    generators, generators_pnl = aggregategenerators(n, busmap, custom_strategies={'p_nom_min': np.sum})
+    strategies = {
+        'p_nom_min': np.sum, 
+        'p_nom_max': 'sum', 
+        'build_year': lambda x: 0, 
+        'lifetime': lambda x: np.inf, 
+        'efficiency': np.mean
+        }
+    generators, generators_pnl = aggregategenerators(n, busmap, custom_strategies=strategies)
     replace_components(n, "Generator", generators, generators_pnl)
 
     for one_port in aggregate_one_ports:
@@ -351,7 +358,11 @@ def aggregate_to_substations(n, buses_i=None):
                                             aggregate_generators_carriers=None,
                                             aggregate_one_ports=["Load", "StorageUnit"],
                                             line_length_factor=1.0,
-                                            generator_strategies={'p_nom_max': 'sum'},
+                                            generator_strategies={'p_nom_max': 'sum', 
+                                                                  'build_year': lambda x: 0, 
+                                                                  'lifetime': lambda x: np.inf, 
+                                                                  'efficiency': np.mean
+                                                                  },
                                             scale_link_capital_costs=False)
         
     return clustering.network, busmap