Fix fuel cost calculation for non-hourly load data

CHANGELOG.md

@@ -25,6 +25,10 @@ Classify the change according to the following categories:
     ### Deprecated
     ### Removed
 
+## Develop fix-nonhourly-fuel-cost
+### Fixed
+- Modified the fuel cost calculation to correctly account for the time step duration when using non-hourly data.
+
 ## Develop degradation-cleanup
 ### Added
 - Battery residual value if choosing replacement strategy for degradation

src/core/utils.jl

@@ -290,7 +290,7 @@ end
 Convert a per hour value (eg. dollars/kWh) to time series that matches the settings.time_steps_per_hour
 """
 function per_hour_value_to_time_series(x::T, time_steps_per_hour::Int, name::String) where T <: Real
-    repeat([x / time_steps_per_hour], 8760 * time_steps_per_hour)
+    repeat([x], 8760 * time_steps_per_hour)
 end
 
 

test/runtests.jl

@@ -1829,45 +1829,81 @@ else  # run HiGHS tests
         end
 
         @testset "OffGrid" begin
-            ## Scenario 1: Solar, Storage, Fixed Generator
-            post_name = "off_grid.json" 
+            ## Scenario 1: Solar, Storage, Fixed Generator - Baseline Test
+            post_name = "off_grid.json"
             post = JSON.parsefile("./scenarios/$post_name")
+
+            # Set up model for time_steps_per_hour = 1 (1-hour intervals)
+            post["Settings"]["time_steps_per_hour"] = 1
             m = Model(optimizer_with_attributes(HiGHS.Optimizer, "output_flag" => false, "log_to_console" => false))
             scen = Scenario(post)
-            r = run_reopt(m, scen)
-            
+            r_1hr = run_reopt(m, scen)
+
             # Test default values 
             @test scen.electric_utility.outage_start_time_step ≈ 1
             @test scen.electric_utility.outage_end_time_step ≈ 8760 * scen.settings.time_steps_per_hour
             @test scen.storage.attr["ElectricStorage"].soc_init_fraction ≈ 1
             @test scen.storage.attr["ElectricStorage"].can_grid_charge ≈ false
             @test scen.generator.fuel_avail_gal ≈ 1.0e9
-            @test scen.generator.min_turn_down_fraction ≈ 0.15
+            @test scen.generator.min_turn_down_fraction ≈ 0.05
             @test sum(scen.electric_load.loads_kw) - sum(scen.electric_load.critical_loads_kw) ≈ 0 # critical loads should equal loads_kw
             @test scen.financial.microgrid_upgrade_cost_fraction ≈ 0
-
-            # Test outputs
-            @test r["ElectricUtility"]["annual_energy_supplied_kwh"] ≈ 0 # no interaction with grid
-            @test r["Financial"]["lifecycle_offgrid_other_capital_costs"] ≈ 2617.092 atol=0.01 # Check straight line depreciation calc
-            @test sum(r["ElectricLoad"]["offgrid_annual_oper_res_provided_series_kwh"]) >= sum(r["ElectricLoad"]["offgrid_annual_oper_res_required_series_kwh"]) # OR provided >= required
-            @test r["ElectricLoad"]["offgrid_load_met_fraction"] >= scen.electric_load.min_load_met_annual_fraction
-            @test r["PV"]["size_kw"] ≈ 5050.0
-            f = r["Financial"]
+
+            # Test baseline outputs
+            @test r_1hr["ElectricUtility"]["annual_energy_supplied_kwh"] ≈ 0
+            @test r_1hr["Financial"]["lifecycle_offgrid_other_capital_costs"] ≈ 2617.092 atol=0.01
+            @test sum(r_1hr["ElectricLoad"]["offgrid_annual_oper_res_provided_series_kwh"]) >= sum(r_1hr["ElectricLoad"]["offgrid_annual_oper_res_required_series_kwh"])
+            @test r_1hr["ElectricLoad"]["offgrid_load_met_fraction"] >= scen.electric_load.min_load_met_annual_fraction
+            @test r_1hr["PV"]["size_kw"] ≈ 5050.0
+
+            # Test financial components sum to LCC
+            f = r_1hr["Financial"]
             @test f["lifecycle_generation_tech_capital_costs"] + f["lifecycle_storage_capital_costs"] + f["lifecycle_om_costs_after_tax"] +
                     f["lifecycle_fuel_costs_after_tax"] + f["lifecycle_chp_standby_cost_after_tax"] + f["lifecycle_elecbill_after_tax"] + 
                     f["lifecycle_offgrid_other_annual_costs_after_tax"] + f["lifecycle_offgrid_other_capital_costs"] + 
                     f["lifecycle_outage_cost"] + f["lifecycle_MG_upgrade_and_fuel_cost"] - 
                     f["lifecycle_production_incentive_after_tax"] ≈ f["lcc"] atol=1.0
-
-            ## Scenario 2: Fixed Generator only
+
+            ## Scenario 2: Solar, Storage, Fixed Generator - 30-minute intervals
+            post["Settings"]["time_steps_per_hour"] = 2
+            m = Model(optimizer_with_attributes(HiGHS.Optimizer, "output_flag" => false, "log_to_console" => false))
+            scen_30min = Scenario(post)
+            r_30min = run_reopt(m, scen_30min)
+
+            # Validate consistency with 1-hour intervals
+            @test r_30min["ElectricUtility"]["annual_energy_supplied_kwh"] ≈ r_1hr["ElectricUtility"]["annual_energy_supplied_kwh"] atol=0.01
+            @test r_30min["Financial"]["lifecycle_offgrid_other_capital_costs"] ≈ r_1hr["Financial"]["lifecycle_offgrid_other_capital_costs"] atol=0.01
+            @test sum(r_30min["ElectricLoad"]["offgrid_annual_oper_res_provided_series_kwh"]) / 2 ≈ sum(r_1hr["ElectricLoad"]["offgrid_annual_oper_res_provided_series_kwh"]) rtol=0.002
+            @test r_30min["ElectricLoad"]["offgrid_load_met_fraction"] ≈ r_1hr["ElectricLoad"]["offgrid_load_met_fraction"] atol=0.01
+            @test r_30min["PV"]["size_kw"] ≈ r_1hr["PV"]["size_kw"] atol=0.01
+            @test r_30min["Generator"]["annual_fuel_consumption_gal"] ≈ r_1hr["Generator"]["annual_fuel_consumption_gal"] rtol=0.002
+            @test r_30min["Generator"]["year_one_fuel_cost_before_tax"] ≈ r_1hr["Generator"]["year_one_fuel_cost_before_tax"] rtol=0.002
+
+            ## Scenario 3: Solar, Storage, Fixed Generator - 15-minute intervals
+            post["Settings"]["time_steps_per_hour"] = 4
+            m = Model(optimizer_with_attributes(HiGHS.Optimizer, "output_flag" => false, "log_to_console" => false))
+            scen_15min = Scenario(post)
+            r_15min = run_reopt(m, scen_15min)
+
+            # Validate consistency with 1-hour intervals
+            @test r_15min["ElectricUtility"]["annual_energy_supplied_kwh"] ≈ r_1hr["ElectricUtility"]["annual_energy_supplied_kwh"] atol=0.01
+            @test r_15min["Financial"]["lifecycle_offgrid_other_capital_costs"] ≈ r_1hr["Financial"]["lifecycle_offgrid_other_capital_costs"] atol=0.01
+            @test sum(r_15min["ElectricLoad"]["offgrid_annual_oper_res_provided_series_kwh"]) / 4 ≈ sum(r_1hr["ElectricLoad"]["offgrid_annual_oper_res_provided_series_kwh"]) rtol=0.002
+            @test r_15min["ElectricLoad"]["offgrid_load_met_fraction"] ≈ r_1hr["ElectricLoad"]["offgrid_load_met_fraction"] atol=0.01
+            @test r_15min["PV"]["size_kw"] ≈ r_1hr["PV"]["size_kw"] atol=0.01
+            @test r_15min["Generator"]["annual_fuel_consumption_gal"] ≈ r_1hr["Generator"]["annual_fuel_consumption_gal"] rtol=0.002
+            @test r_15min["Generator"]["year_one_fuel_cost_before_tax"] ≈ r_1hr["Generator"]["year_one_fuel_cost_before_tax"] rtol=0.002
+
+            ## Scenario 4: Fixed Generator only
+            @info "Running Scenario 3: Fixed Generator only"
             post["ElectricLoad"]["annual_kwh"] = 100.0
             post["PV"]["max_kw"] = 0.0
             post["ElectricStorage"]["max_kw"] = 0.0
             post["Generator"]["min_turn_down_fraction"] = 0.0
-
+        
             m = Model(optimizer_with_attributes(HiGHS.Optimizer, "output_flag" => false, "log_to_console" => false))
             r = run_reopt(m, post)
-
+        
             # Test generator outputs
             @test r["Generator"]["annual_fuel_consumption_gal"] ≈ 7.52 # 99 kWh * 0.076 gal/kWh
             @test r["Generator"]["annual_energy_produced_kwh"] ≈ 99.0
@@ -1878,30 +1914,31 @@ else  # run HiGHS tests
             @test r["Financial"]["initial_capital_costs_after_incentives"] ≈ 700*100 atol=0.1
             @test r["Financial"]["replacements_future_cost_after_tax"] ≈ 700*100
             @test r["Financial"]["replacements_present_cost_after_tax"] ≈ 100*(324.235442*(1-0.26)) atol=0.1 
-
-            ## Scenario 3: Fixed Generator that can meet load, but cannot meet load operating reserve requirement
+
+            ## Scenario 5: Fixed Generator that can meet load, but cannot meet load operating reserve requirement
+            @info "Running Scenario 4: Fixed Generator with Load Operating Reserve Requirement"
             ## This test ensures the load operating reserve requirement is being enforced
             post["ElectricLoad"]["doe_reference_name"] = "FlatLoad"
             post["ElectricLoad"]["annual_kwh"] = 876000.0 # requires 100 kW gen
             post["ElectricLoad"]["min_load_met_annual_fraction"] = 1.0 # requires additional generator capacity
             post["PV"]["max_kw"] = 0.0
             post["ElectricStorage"]["max_kw"] = 0.0
             post["Generator"]["min_turn_down_fraction"] = 0.0
-
+        
             m = Model(optimizer_with_attributes(HiGHS.Optimizer, "output_flag" => false, "log_to_console" => false))
             r = run_reopt(m, post)
-
+        
             # Test generator outputs
             @test typeof(r) == Model # this is true when the model is infeasible
-
-            ### Scenario 3: Indonesia. Wind (custom prod) and Generator only
+        
+            ## Scenario 6: Indonesia. Wind (custom prod) and Generator only
             m = Model(optimizer_with_attributes(HiGHS.Optimizer, "output_flag" => false, "log_to_console" => false, "mip_rel_gap" => 0.01, "presolve" => "on"))
             post_name = "wind_intl_offgrid.json" 
             post = JSON.parsefile("./scenarios/$post_name")
             post["ElectricLoad"]["loads_kw"] = [10.0 for i in range(1,8760)]
             scen = Scenario(post)
             post["Wind"]["production_factor_series"] =  reduce(vcat, readdlm("./data/example_wind_prod_factor_kw.csv", '\n', header=true)[1])
-
+        
             results = run_reopt(m, post)
 
             @test results["ElectricLoad"]["offgrid_load_met_fraction"] >= scen.electric_load.min_load_met_annual_fraction
@@ -1911,11 +1948,10 @@ else  # run HiGHS tests
                     f["lifecycle_offgrid_other_annual_costs_after_tax"] + f["lifecycle_offgrid_other_capital_costs"] + 
                     f["lifecycle_outage_cost"] + f["lifecycle_MG_upgrade_and_fuel_cost"] - 
                     f["lifecycle_production_incentive_after_tax"] ≈ f["lcc"] atol=1.0
-
+        
             windOR = sum(results["Wind"]["electric_to_load_series_kw"]  * post["Wind"]["operating_reserve_required_fraction"])
             loadOR = sum(post["ElectricLoad"]["loads_kw"] * scen.electric_load.operating_reserve_required_fraction)
             @test sum(results["ElectricLoad"]["offgrid_annual_oper_res_required_series_kwh"]) ≈ loadOR  + windOR atol=1.0
-
         end
 
         @testset "GHP" begin

test/scenarios/off_grid.json

@@ -29,7 +29,8 @@
         "electric_efficiency_full_load": 0.3232898,
         "electric_efficiency_half_load": 0.3232898,
         "om_cost_per_kw": 20.0,
-        "fuel_cost_per_gallon": 3.0
+        "fuel_cost_per_gallon": 3.0,
+        "min_turn_down_fraction": 0.05
     },
     "ElectricLoad": {
         "doe_reference_name": "RetailStore",