Fervo cape station 500 MWe

src/geophires_x/Economics.py

@@ -6,7 +6,7 @@
 from geophires_x import EconomicsSam
 from geophires_x.EconomicsSam import calculate_sam_economics, SamEconomicsCalculations
 from geophires_x.EconomicsUtils import BuildPricingModel, wacc_output_parameter, nominal_discount_rate_parameter, \
-    real_discount_rate_parameter
+    real_discount_rate_parameter, after_tax_irr_parameter
 from geophires_x.OptionList import Configuration, WellDrillingCostCorrelation, EconomicModel, EndUseOptions, PlantType, \
     _WellDrillingCostCorrelationCitation
 from geophires_x.Parameter import intParameter, floatParameter, OutputParameter, ReadParameter, boolParameter, \
@@ -884,7 +884,7 @@ def __init__(self, model: Model):
             PreferredUnits=PercentUnit.TENTH,
             CurrentUnits=PercentUnit.TENTH,
             ErrMessage="assume default fraction of investment in bonds (0.5)",
-            ToolTipText="Fraction of geothermal project financing through bonds (see docs)"
+            ToolTipText="Fraction of geothermal project financing through bonds (debt)."
         )
         self.BIR = self.ParameterDict[self.BIR.Name] = floatParameter(
             "Inflated Bond Interest Rate",
@@ -1581,12 +1581,19 @@ def __init__(self, model: Model):
             PreferredUnits=CurrencyUnit.MDOLLARS,
             CurrentUnits=CurrencyUnit.MDOLLARS
         )
+
+        # See TODO re:parameterizing indirect costs at src/geophires_x/Economics.py:652
+        #    (https://github.com/NREL/GEOPHIRES-X/issues/383)
         self.Cexpl = self.OutputParameterDict[self.Cexpl.Name] = OutputParameter(
             Name="Exploration cost",
             display_name='Exploration costs',
             UnitType=Units.CURRENCY,
             PreferredUnits=CurrencyUnit.MDOLLARS,
-            CurrentUnits=CurrencyUnit.MDOLLARS
+            CurrentUnits=CurrencyUnit.MDOLLARS,
+            ToolTipText=f'Default correlation: 60% of the cost of one production well plus 15% contingency '
+                        f'plus 12% indirect costs. '
+                        f'Provide {self.ccexpladjfactor.Name} to multiply the default correlation. '
+                        f'Provide {self.ccexplfixed.Name} to override the default correlation and set your own cost.'
         )
 
         self.Cwell = self.OutputParameterDict[self.Cwell.Name] = OutputParameter(
@@ -1597,6 +1604,7 @@ def __init__(self, model: Model):
             CurrentUnits=CurrencyUnit.MDOLLARS,
 
             # See TODO re:parameterizing indirect costs at src/geophires_x/Economics.py:652
+            #    (https://github.com/NREL/GEOPHIRES-X/issues/383)
             ToolTipText="Includes total drilling and completion cost of all injection and production wells and "
                         "laterals, plus 5% indirect costs."
         )
@@ -1776,6 +1784,8 @@ def __init__(self, model: Model):
             CurrentUnits=PercentUnit.PERCENT
         )
 
+        self.after_tax_irr = self.OutputParameterDict[self.after_tax_irr.Name] = (
+            after_tax_irr_parameter())
         self.real_discount_rate = self.OutputParameterDict[self.real_discount_rate.Name] = (
             real_discount_rate_parameter())
         self.nominal_discount_rate = self.OutputParameterDict[self.nominal_discount_rate.Name] = (
@@ -2767,7 +2777,9 @@ def Calculate(self, model: Model) -> None:
             self.nominal_discount_rate.value = self.sam_economics_calculations.nominal_discount_rate.value
             self.ProjectNPV.value = self.sam_economics_calculations.project_npv.quantity().to(
                 convertible_unit(self.ProjectNPV.CurrentUnits)).magnitude
-            self.ProjectIRR.value = self.sam_economics_calculations.project_irr.quantity().to(
+
+            self.ProjectIRR.value = non_calculated_output_placeholder_val  # SAM calculates After-Tax IRR instead
+            self.after_tax_irr.value = self.sam_economics_calculations.after_tax_irr.quantity().to(
                 convertible_unit(self.ProjectIRR.CurrentUnits)).magnitude
 
             self.ProjectVIR.value = non_calculated_output_placeholder_val  # TODO SAM VIR

src/geophires_x/EconomicsSam.py

@@ -27,7 +27,12 @@
 
 from geophires_x import Model as Model
 from geophires_x.EconomicsSamCashFlow import _calculate_sam_economics_cash_flow
-from geophires_x.EconomicsUtils import BuildPricingModel, wacc_output_parameter, nominal_discount_rate_parameter
+from geophires_x.EconomicsUtils import (
+    BuildPricingModel,
+    wacc_output_parameter,
+    nominal_discount_rate_parameter,
+    after_tax_irr_parameter,
+)
 from geophires_x.GeoPHIRESUtils import is_float, is_int
 from geophires_x.OptionList import EconomicModel, EndUseOptions
 from geophires_x.Parameter import Parameter, OutputParameter, floatParameter
@@ -44,24 +49,22 @@ class SamEconomicsCalculations:
             CurrentUnits=EnergyCostUnit.CENTSSPERKWH,
         )
     )
+
     capex: OutputParameter = field(
         default_factory=lambda: OutputParameter(
             UnitType=Units.CURRENCY,
             CurrentUnits=CurrencyUnit.MDOLLARS,
         )
     )
+
     project_npv: OutputParameter = field(
         default_factory=lambda: OutputParameter(
             UnitType=Units.CURRENCY,
             CurrentUnits=CurrencyUnit.MDOLLARS,
         )
     )
-    project_irr: OutputParameter = field(
-        default_factory=lambda: OutputParameter(
-            UnitType=Units.PERCENT,
-            CurrentUnits=PercentUnit.PERCENT,
-        )
-    )
+
+    after_tax_irr: OutputParameter = field(default_factory=after_tax_irr_parameter)
 
     nominal_discount_rate: OutputParameter = field(default_factory=nominal_discount_rate_parameter)
 
@@ -157,7 +160,7 @@ def sf(_v: float) -> float:
 
     sam_economics: SamEconomicsCalculations = SamEconomicsCalculations(sam_cash_flow_profile=cash_flow)
     sam_economics.lcoe_nominal.value = sf(single_owner.Outputs.lcoe_nom)
-    sam_economics.project_irr.value = sf(single_owner.Outputs.project_return_aftertax_irr)
+    sam_economics.after_tax_irr.value = sf(single_owner.Outputs.project_return_aftertax_irr)
     sam_economics.project_npv.value = sf(single_owner.Outputs.project_return_aftertax_npv * 1e-6)
     sam_economics.capex.value = single_owner.Outputs.adjusted_installed_cost * 1e-6
 

src/geophires_x/EconomicsUtils.py

@@ -37,27 +37,39 @@ def BuildPricingModel(plantlifetime: int, StartPrice: float, EndPrice: float,
     return Price
 
 
+def after_tax_irr_parameter() -> OutputParameter:
+    return OutputParameter(
+        Name='After-Tax IRR',
+        UnitType=Units.PERCENT,
+        CurrentUnits=PercentUnit.PERCENT,
+        PreferredUnits=PercentUnit.PERCENT,
+        ToolTipText='The After-Tax IRR (internal rate of return) is the nominal discount rate that corresponds to '
+                    'a net present value (NPV) of zero for PPA SAM Economic models. '
+                    'See https://samrepo.nrelcloud.org/help/mtf_irr.html.'
+    )
+
+
 def real_discount_rate_parameter() -> OutputParameter:
     return OutputParameter(
-            Name="Real Discount Rate",
-            UnitType=Units.PERCENT,
-            CurrentUnits=PercentUnit.PERCENT,
-            PreferredUnits=PercentUnit.PERCENT,
-        )
+        Name="Real Discount Rate",
+        UnitType=Units.PERCENT,
+        CurrentUnits=PercentUnit.PERCENT,
+        PreferredUnits=PercentUnit.PERCENT,
+    )
 
 
 def nominal_discount_rate_parameter() -> OutputParameter:
     return OutputParameter(
-            Name="Nominal Discount Rate",
-            ToolTipText="Nominal Discount Rate is displayed for SAM Economic Models. "
-                        "It is calculated "
-                        "per https://samrepo.nrelcloud.org/help/fin_single_owner.html?q=nominal+discount+rate: "
-                        "Nominal Discount Rate = [ ( 1 + Real Discount Rate ÷ 100 ) "
-                        "× ( 1 + Inflation Rate ÷ 100 ) - 1 ] × 100.",
-            UnitType=Units.PERCENT,
-            CurrentUnits=PercentUnit.PERCENT,
-            PreferredUnits=PercentUnit.PERCENT,
-        )
+        Name="Nominal Discount Rate",
+        ToolTipText="Nominal Discount Rate is displayed for SAM Economic Models. "
+                    "It is calculated "
+                    "per https://samrepo.nrelcloud.org/help/fin_single_owner.html?q=nominal+discount+rate: "
+                    "Nominal Discount Rate = [ ( 1 + Real Discount Rate ÷ 100 ) "
+                    "× ( 1 + Inflation Rate ÷ 100 ) - 1 ] × 100.",
+        UnitType=Units.PERCENT,
+        CurrentUnits=PercentUnit.PERCENT,
+        PreferredUnits=PercentUnit.PERCENT,
+    )
 
 
 def wacc_output_parameter() -> OutputParameter:

src/geophires_x/Outputs.py

@@ -1,4 +1,5 @@
 import datetime
+import math
 import time
 import sys
 from pathlib import Path
@@ -274,7 +275,12 @@ def PrintOutputs(self, model: Model):
                 # TODO should use CurrentUnits instead of PreferredUnits
                 f.write(f'      {npv_field_label}{e_npv.value:10.2f} {e_npv.PreferredUnits.value}\n')
 
-                f.write(f'      {econ.ProjectIRR.display_name}:                                     {econ.ProjectIRR.value:10.2f} {econ.ProjectIRR.PreferredUnits.value}\n')
+                irr_output_param: OutputParameter = econ.ProjectIRR \
+                    if econ.econmodel.value != EconomicModel.SAM_SINGLE_OWNER_PPA else econ.after_tax_irr
+                irr_field_label = Outputs._field_label(irr_output_param.display_name, 49)
+                irr_display_value = f'{irr_output_param.value:10.2f}' \
+                    if not math.isnan(irr_output_param.value) else 'NaN'
+                f.write(f'      {irr_field_label}{irr_display_value} {irr_output_param.CurrentUnits.value}\n')
 
                 if econ.econmodel.value != EconomicModel.SAM_SINGLE_OWNER_PPA:
                     # VIR, MOIC, and Payback period not currently supported by SAM economic model(s)

src/geophires_x/sam_economics/Generic_400_MWe/Generic_400_MWe.json

@@ -220,7 +220,7 @@
     "pbi_oth_escal" : 0,
     "pbi_oth_tax_fed" : 1,
     "pbi_oth_tax_sta" : 1,
-    "term_tenor" : 30,
+    "term_tenor" : 20,
     "term_int_rate" : 5,
     "dscr" : 1.05,
     "dscr_limit_debt_fraction" : 0,

src/geophires_x/sam_economics/Generic_400_MWe/Generic_400_MWe_singleowner.json

@@ -172,7 +172,7 @@
 	"pbi_oth_escal" : 0,
 	"pbi_oth_tax_fed" : 1,
 	"pbi_oth_tax_sta" : 1,
-	"term_tenor" : 30,
+	"term_tenor" : 20,
 	"term_int_rate" : 5,
 	"dscr" : 1.05,
 	"dscr_limit_debt_fraction" : 0,

src/geophires_x_client/geophires_x_result.py

@@ -862,8 +862,8 @@ def _parse_number(self, number_str, field='string') -> int | float:
             return None
 
         try:
-            number_str = number_str.replace(',', '')
-            if '.' in number_str:
+            number_str = number_str.replace(',', '').lower()
+            if '.' in number_str or number_str == 'nan':
                 # TODO should probably ideally use decimal.Decimal to preserve precision,
                 #  i.e. 1.00 for USD instead of 1.0
                 return float(number_str)

src/geophires_x_schema_generator/geophires-request.json

@@ -1595,7 +1595,7 @@
       "maximum": null
     },
     "Fraction of Investment in Bonds": {
-      "description": "Fraction of geothermal project financing through bonds (see docs)",
+      "description": "Fraction of geothermal project financing through bonds (debt).",
       "type": "number",
       "units": "",
       "category": "Economics",

src/geophires_x_schema_generator/geophires-result.json

@@ -362,7 +362,7 @@
         "Total surface equipment costs": {},
         "Exploration costs": {
           "type": "number",
-          "description": "Exploration cost",
+          "description": "Exploration cost. Default correlation: 60% of the cost of one production well plus 15% contingency plus 12% indirect costs. Provide Exploration Capital Cost Adjustment Factor to multiply the default correlation. Provide Exploration Capital Cost to override the default correlation and set your own cost.",
           "units": "MUSD"
         },
         "Investment Tax Credit": {