diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index 86c79026..89d5cd7d 100755
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -2905,7 +2905,9 @@ def add_industry(n, costs):
 
     if cf_industry["waste_to_energy"] or cf_industry["waste_to_energy_cc"]:
 
-        non_sequestered_hvc_locations = pd.Index(spatial.oil.demand_locations) + " non-sequestered HVC"
+        non_sequestered_hvc_locations = (
+            pd.Index(spatial.oil.demand_locations) + " non-sequestered HVC"
+        )
 
         n.madd(
             "Bus",
@@ -2956,7 +2958,7 @@ def add_industry(n, costs):
                 * costs.at["waste CHP", "efficiency"],
                 marginal_cost=costs.at["waste CHP", "VOM"],
                 efficiency=costs.at["waste CHP", "efficiency"],
-                efficiency2=costs.at['waste CHP', 'efficiency-heat'],
+                efficiency2=costs.at["waste CHP", "efficiency-heat"],
                 efficiency3=costs.at["oil", "CO2 intensity"],
                 lifetime=costs.at["waste CHP", "lifetime"],
             )
@@ -2977,8 +2979,9 @@ def add_industry(n, costs):
                 * costs.at["waste CHP CC", "efficiency"],
                 marginal_cost=costs.at["waste CHP CC", "VOM"],
                 efficiency=costs.at["waste CHP CC", "efficiency"],
-                efficiency2=costs.at["waste CHP CC", 'efficiency-heat'],
-                efficiency3=costs.at["oil", "CO2 intensity"] * (1 - options["cc_fraction"]),
+                efficiency2=costs.at["waste CHP CC", "efficiency-heat"],
+                efficiency3=costs.at["oil", "CO2 intensity"]
+                * (1 - options["cc_fraction"]),
                 efficiency4=costs.at["oil", "CO2 intensity"] * options["cc_fraction"],
                 lifetime=costs.at["waste CHP CC", "lifetime"],
             )