slice pre-revenue years based on construction years (instead of hardcoding to 1). note this doesn't have any effect until SAM-EM supports multiple construction years (NREL#406)

Author: softwareengineerprogrammer

src/geophires_x/Economics.py

@@ -3356,11 +3356,14 @@ def _calculate_sam_economics(self, model: Model) -> None:
 
 
         if self.royalty_rate.Provided:
-            average_annual_royalties = np.average(  # TODO unit conversion
-                self.sam_economics_calculations.royalties_opex.value[1:]  # ignore pre-revenue year(s) (Year 0)
+            # ignore pre-revenue year(s) (e.g. Year 0)
+            pre_revenue_years_slice_index = model.surfaceplant.construction_years.value
+
+            average_annual_royalties = np.average(
+                self.sam_economics_calculations.royalties_opex.value[pre_revenue_years_slice_index:]
             )
 
-            self.royalties_average_annual_cost.value = average_annual_royalties
+            self.royalties_average_annual_cost.value = average_annual_royalties  # TODO unit conversion
             self.Coam.value += self.royalties_average_annual_cost.quantity().to(self.Coam.CurrentUnits.value).magnitude
 
             self.royalty_holder_npv.value = calculate_npv(
@@ -3370,7 +3373,7 @@ def _calculate_sam_economics(self, model: Model) -> None:
             )
             self.royalty_holder_annual_revenue.value = self.royalties_average_annual_cost.value
             self.royalty_holder_total_revenue.value = np.sum(  # TODO unit conversion
-                self.sam_economics_calculations.royalties_opex.value[1:]  # ignore pre-revenue year(s) (Year 0)
+                self.sam_economics_calculations.royalties_opex.value[pre_revenue_years_slice_index:]
             )