diff --git a/main.py b/main.py
index 0b261b1..18794d7 100644
--- a/main.py
+++ b/main.py
@@ -27,9 +27,9 @@ from energy_systems_sizing import EnergySystemsSizing
 
 from life_cycle_costs import LifeCycleCosts
 
-def _npv_from_list(discount_rate, list_cashflow):
-  lcc_value = np.npv(discount_rate,list_cashflow)
-  raise KeyError('bad inputs')
+def _npv_from_list(npv_discount_rate, list_cashflow):
+  lcc_value = np.npv(npv_discount_rate, list_cashflow)
+  return lcc_value
 
 def _search_archetype(costs_catalog, building_function):
   costs_archetypes = costs_catalog.entries('archetypes').archetypes
@@ -154,8 +154,8 @@ for retrofitting_scenario in retrofitting_scenarios:
                            lcc.calculate_total_operational_costs()['PV_maintenance']
     df_operational_incomes = lcc.calculate_total_operational_incomes()['Incomes electricity']
 
-    life_cycle_costs_capital_skin=_npv_from_list(discount_rate , df_capital_costs_skin.values.tolist())
-    life_cycle_costs_capital_systems=_npv_from_list(discount_rate , df_capital_costs_systems.values.tolist())
+    life_cycle_costs_capital_skin = _npv_from_list(discount_rate, df_capital_costs_skin.values.tolist())
+    life_cycle_costs_capital_systems = _npv_from_list(discount_rate, df_capital_costs_systems.values.tolist())
     life_cycle_costs_end_of_life_costs = _npv_from_list(discount_rate, df_end_of_life_costs.values.tolist())
     life_cycle_operational_costs = _npv_from_list(discount_rate, df_operational_costs.values.tolist())
     life_cycle_maintenance_costs = _npv_from_list(discount_rate, df_maintenance_costs.values.tolist())
@@ -176,5 +176,6 @@ for retrofitting_scenario in retrofitting_scenarios:
                                 'total_operational_costs','total_maintenance_costs','life_cycle_costs',
                                 'maintenance_costs']
 
-    life_cycle_results.to_excel(Path(__file__).parent/'out_files'/f'Results{building.name}.xlsx', index=True)
+
+#life_cycle_results.to_excel(Path(__file__).parent/'out_files'/f'Results{building.name}.xlsx', index=True)