Fix Bond Financing Start Year off-by-one index implementation error. Treat bond financing start years prior to construction as equivalent to the first construction year.

Author: softwareengineerprogrammer

src/geophires_x/Economics.py

@@ -1185,9 +1185,9 @@ def __init__(self, model: Model):
                         f'and normalized to sum to 1.0.'
         )
 
-        default_bond_financing_start_year = 0
-        latest_allowed_bond_financing_start_year_index = 0
         bond_financing_start_year_name = 'Bond Financing Start Year'
+        default_bond_financing_start_year = -1*(MAX_CONSTRUCTION_YEARS - 1)
+        latest_allowed_bond_financing_start_year_index = 0
         self.bond_financing_start_year = self.ParameterDict[self.bond_financing_start_year.Name] = intParameter(
             bond_financing_start_year_name,
             DefaultValue=default_bond_financing_start_year,
@@ -1201,15 +1201,15 @@ def __init__(self, model: Model):
             ToolTipText=f'Project year index when bond financing (debt/loans) starts '
                         f'(if {self.FIB.Name} is >0). '
                         f'Prior years will be financed with equity only. '
-                        f'By default, bond financing starts during the first construction year '
+                        f'By default, bond financing starts during the first construction year '  # TODO lead with this
                         f'which has year index {{({model.surfaceplant.construction_years.Name} - 1) * -1}}. '
-                        f'For example, a project with 4 '
-                        # f'{model.surfaceplant.construction_years.Name} '
-                        'construction years '
-                        f'where bond '
-                        f'financing starts on the third {model.surfaceplant.construction_years.Name[:-1]} would have '
-                        f'a {bond_financing_start_year_name} value of -1; construction starts in Year -3, the second'
-                        f'year is Year -2, and the final 2 bond-financed construction years are Year -1 and Year 0.'
+                        f'For example, a project with 4 construction years '
+                        f'where bond financing starts on the third {model.surfaceplant.construction_years.Name[:-1]} '
+                        f'would have a {bond_financing_start_year_name} value of -1; construction starts in Year -3, '
+                        f'the second year is Year -2, and the final 2 bond-financed construction years are Year -1 '
+                        f'and Year 0. '
+                        f'Bond financing will start on the first construction year if the specified year index is '
+                        f'prior to the first construction year.'
         )
 
         self.contingency_percentage = self.ParameterDict[self.contingency_percentage.Name] = floatParameter(

src/geophires_x/EconomicsSam.py

@@ -204,9 +204,9 @@ def _inv_msg(param_name: str, invalid_value: Any, supported_description: str) ->
 
     construction_years = model.surfaceplant.construction_years.value
     if abs(econ.bond_financing_start_year.value) >= construction_years:
-        raise ValueError(
-            f'{econ.bond_financing_start_year.Name} ({econ.bond_financing_start_year.value}) may not be earlier than '
-            f'first {model.surfaceplant.construction_years.Name[:-1]} ({-1*(construction_years-1)}). '
+        model.logger.debug(
+            f'{econ.bond_financing_start_year.Name} ({econ.bond_financing_start_year.value}) is earlier than '
+            f'first {model.surfaceplant.construction_years.Name[:-1]} ({-1 * (construction_years - 1)}). (OK)'
         )
 
 

src/geophires_x/EconomicsSamPreRevenue.py

@@ -68,8 +68,9 @@ def calculate_pre_revenue_costs_and_cashflow(model: 'Model') -> PreRevenueCostsA
     construction_years: int = model.surfaceplant.construction_years.value
 
     # Translate from negative year index input value to start-year-0-indexed calculation value
-    debt_financing_start_year: int = (
-        construction_years - abs(econ.bond_financing_start_year.value) if econ.bond_financing_start_year.Provided else 0
+    debt_financing_start_year: int = max(
+        construction_years - abs(econ.bond_financing_start_year.value) - 1,
+        0,  # Treat bond financing years prior to construction as starting in the first year of construction
     )
 
     return _calculate_pre_revenue_costs_and_cashflow(

src/geophires_x_schema_generator/geophires-request.json

@@ -1785,11 +1785,11 @@
       "maximum": 1.0
     },
     "Bond Financing Start Year": {
-      "description": "Project year index when bond financing (debt/loans) starts (if Fraction of Investment in Bonds is >0). Prior years will be financed with equity only. By default, bond financing starts during the first construction year which has year index {(Construction Years - 1) * -1}. For example, a project with 4 construction years where bond financing starts on the third Construction Year would have a Bond Financing Start Year value of -1; construction starts in Year -3, the secondyear is Year -2, and the final 2 bond-financed construction years are Year -1 and Year 0.",
+      "description": "Project year index when bond financing (debt/loans) starts (if Fraction of Investment in Bonds is >0). Prior years will be financed with equity only. By default, bond financing starts during the first construction year which has year index {(Construction Years - 1) * -1}. For example, a project with 4 construction years where bond financing starts on the third Construction Year would have a Bond Financing Start Year value of -1; construction starts in Year -3, the second year is Year -2, and the final 2 bond-financed construction years are Year -1 and Year 0. Bond financing will start on the first construction year if the specified year index is prior to the first construction year.",
       "type": "integer",
       "units": "yr",
       "category": "Economics",
-      "default": 0,
+      "default": -14,
       "minimum": -14,
       "maximum": 0
     },