Merge pull request #593 from NatLabRockies/hrly-gen-costs

Add Generator O&M Costs by Hour

Author: adfarth

CHANGELOG.md

@@ -25,6 +25,10 @@ Classify the change according to the following categories:
     ### Deprecated
     ### Removed
 
+## hrly-gen-costs
+### Added
+- **Generator** **om_cost_per_hr_per_kw_rated**: Generator non-fuel variable operations and maintenance costs in \$/hr/kw_rated (default of 0.0)
+
 ## v0.58.1 
 ### Fixed
 - Calculation of offgrid_microgrid_lcoe_dollars_per_kwh for sub-hourly runs.

src/constraints/generator_constraints.jl

@@ -36,7 +36,6 @@ function add_binGenIsOnInTS_constraints(m,p)
 	end 
 end
 
-
 function add_gen_can_run_constraints(m,p)
 	if p.s.generator.only_runs_during_grid_outage
 		for ts in p.time_steps_with_grid, t in p.techs.gen
@@ -58,6 +57,38 @@ function add_gen_rated_prod_constraint(m, p)
 	)
 end
 
+"""
+    add_generator_hourly_om_charges(m, p)
+
+- add decision variable "dvOMByHourBySizeGen" for the hourly Generator operations and maintenance costs
+- add the cost to TotalPerUnitHourOMCosts
+"""
+function add_generator_hourly_om_charges(m, p)
+    dv = "dvOMByHourBySizeGen"
+    m[Symbol(dv)] = @variable(m, [p.techs.gen, p.time_steps], base_name=dv, lower_bound=0)
+
+    #Constraint Generator-hourly-om-a: om per hour, per time step >= per_unit_size_cost * size for when on, >= zero when off
+	@constraint(m, GeneratorHourlyOMBySizeA[t in p.techs.gen, ts in p.time_steps],
+        p.s.generator.om_cost_per_hr_per_kw_rated * m[Symbol("dvSize")][t] -
+        (p.s.generator.existing_kw + p.s.generator.max_kw) * p.s.generator.om_cost_per_hr_per_kw_rated * (1-m[Symbol("binGenIsOnInTS")][t,ts])
+            <= m[Symbol("dvOMByHourBySizeGen")][t, ts]
+    )
+	#Constraint Generator-hourly-om-b: om per hour, per time step <= per_unit_size_cost * size for each hour
+	@constraint(m, GeneratorHourlyOMBySizeB[t in p.techs.gen, ts in p.time_steps],
+        p.s.generator.om_cost_per_hr_per_kw_rated * m[Symbol("dvSize")][t]
+            >= m[Symbol("dvOMByHourBySizeGen")][t, ts]
+    )
+	#Constraint Generator-hourly-om-c: om per hour, per time step <= zero when off, <= per_unit_size_cost*max_size
+	@constraint(m, GeneratorHourlyOMBySizeC[t in p.techs.gen, ts in p.time_steps],
+        (p.s.generator.existing_kw + p.s.generator.max_kw) * p.s.generator.om_cost_per_hr_per_kw_rated * m[Symbol("binGenIsOnInTS")][t,ts]
+            >= m[Symbol("dvOMByHourBySizeGen")][t, ts]
+    )
+    
+    m[:TotalHourlyGenOMCosts] = @expression(m, p.third_party_factor * p.pwf_om * 
+    	sum(m[Symbol(dv)][t, ts] * p.hours_per_time_step for t in p.techs.gen, ts in p.time_steps))
+    nothing
+end
+
 
 """
     add_gen_constraints(m, p)
@@ -70,6 +101,11 @@ function add_gen_constraints(m, p)
     add_gen_can_run_constraints(m,p)
     add_gen_rated_prod_constraint(m,p)
 
+	m[:TotalHourlyGenOMCosts] = 0
+	if p.s.generator.om_cost_per_hr_per_kw_rated > 1.0E-7
+        add_generator_hourly_om_charges(m, p)
+    end
+
     m[:TotalGenPerUnitProdOMCosts] = @expression(m, p.third_party_factor * p.pwf_om *
         sum(p.s.generator.om_cost_per_kwh * p.hours_per_time_step *
         m[:dvRatedProduction][t, ts] for t in p.techs.gen, ts in p.time_steps)

src/core/generator.jl

@@ -9,6 +9,7 @@
     installed_cost_per_kw::Real = off_grid_flag ? 880 : only_runs_during_grid_outage ? 650.0 : 800.0,
     om_cost_per_kw::Real = off_grid_flag ? 10.0 : 20.0,
     om_cost_per_kwh::Real = 0.0,
+    om_cost_per_hr_per_kw_rated::Float64 = 0.0, # Generator non-fuel variable operations and maintenance costs in \$/hr/kw_rated
     fuel_cost_per_gallon::Real = 2.25,
     electric_efficiency_full_load::Real = 0.322,
     electric_efficiency_half_load::Real = electric_efficiency_full_load,
@@ -57,6 +58,7 @@ struct Generator <: AbstractGenerator
     installed_cost_per_kw
     om_cost_per_kw
     om_cost_per_kwh
+    om_cost_per_hr_per_kw_rated
     fuel_cost_per_gallon
     electric_efficiency_full_load
     electric_efficiency_half_load
@@ -104,6 +106,7 @@ struct Generator <: AbstractGenerator
         installed_cost_per_kw::Real = off_grid_flag ? 880 : only_runs_during_grid_outage ? 650.0 : 800.0,
         om_cost_per_kw::Real= off_grid_flag ? 10.0 : 20.0,
         om_cost_per_kwh::Real = 0.0,
+        om_cost_per_hr_per_kw_rated::Float64 = 0.0, # Generator non-fuel variable operations and maintenance costs in \$/hr/kw_rated
         fuel_cost_per_gallon::Real = 2.25,
         electric_efficiency_full_load::Real = 0.322,
         electric_efficiency_half_load::Real = electric_efficiency_full_load,
@@ -152,6 +155,7 @@ struct Generator <: AbstractGenerator
             installed_cost_per_kw,
             om_cost_per_kw,
             om_cost_per_kwh,
+            om_cost_per_hr_per_kw_rated,
             fuel_cost_per_gallon,
             electric_efficiency_full_load,
             electric_efficiency_half_load,

src/core/reopt.jl

@@ -274,6 +274,7 @@ function build_reopt!(m::JuMP.AbstractModel, p::REoptInputs)
             add_gen_constraints(m, p)
             m[:TotalPerUnitProdOMCosts] += m[:TotalGenPerUnitProdOMCosts]
             m[:TotalFuelCosts] += m[:TotalGenFuelCosts]
+			m[:TotalPerUnitHourOMCosts] += m[:TotalHourlyGenOMCosts]
         end
 
         if !isempty(p.techs.chp)

src/mpc/model.jl

@@ -153,6 +153,7 @@ function build_mpc!(m::JuMP.AbstractModel, p::MPCInputs)
 
     m[:TotalFuelCosts] = 0.0
     m[:TotalPerUnitProdOMCosts] = 0.0
+	m[:TotalPerUnitHourOMCosts] = 0.0
 
     if !isempty(p.techs.gen)
         add_gen_constraints(m, p)
@@ -164,6 +165,7 @@ function build_mpc!(m::JuMP.AbstractModel, p::MPCInputs)
             sum(m[:dvFuelUsage][t,ts] * p.s.generator.fuel_cost_per_gallon for t in p.techs.gen, ts in p.time_steps)
         )
         m[:TotalFuelCosts] += m[:TotalGenFuelCosts]
+		m[:TotalPerUnitHourOMCosts] += m[:TotalHourlyGenOMCosts]
 	end
 
 	add_elec_utility_expressions(m, p)
@@ -203,7 +205,7 @@ function build_mpc!(m::JuMP.AbstractModel, p::MPCInputs)
 	@expression(m, Costs,
 
 		# Variable O&M
-		m[:TotalPerUnitProdOMCosts] +
+		m[:TotalPerUnitProdOMCosts] + m[:TotalPerUnitHourOMCosts] +
 
 		# Total Generator Fuel Costs
         m[:TotalFuelCosts] +

src/mpc/structs.jl

@@ -261,6 +261,7 @@ function MPCGenerator(;
     only_runs_during_grid_outage::Bool = true,
     sells_energy_back_to_grid::Bool = false,
     om_cost_per_kwh::Real=0.0,
+    om_cost_per_hr_per_kw_rated::Real=0.0,
     )
 ```
 """
@@ -276,6 +277,7 @@ struct MPCGenerator <: AbstractGenerator
     only_runs_during_grid_outage
     sells_energy_back_to_grid
     om_cost_per_kwh
+    om_cost_per_hr_per_kw_rated
 
     function MPCGenerator(;
         size_kw::Real,
@@ -288,6 +290,7 @@ struct MPCGenerator <: AbstractGenerator
         only_runs_during_grid_outage::Bool = true,
         sells_energy_back_to_grid::Bool = false,
         om_cost_per_kwh::Real=0.0,
+        om_cost_per_hr_per_kw_rated::Real=0.0,
         )
 
         max_kw = size_kw
@@ -304,6 +307,7 @@ struct MPCGenerator <: AbstractGenerator
             only_runs_during_grid_outage,
             sells_energy_back_to_grid,
             om_cost_per_kwh,
+            om_cost_per_hr_per_kw_rated
         )
     end
 end

src/results/generator.jl

@@ -4,8 +4,8 @@
 - `size_kw` Optimal generator capacity
 - `lifecycle_fixed_om_cost_after_tax` Lifecycle fixed operations and maintenance cost in present value, after tax
 - `year_one_fixed_om_cost_before_tax` fixed operations and maintenance cost over the first year, before considering tax benefits
-- `lifecycle_variable_om_cost_after_tax` Lifecycle variable operations and maintenance cost in present value, after tax
-- `year_one_variable_om_cost_before_tax` variable operations and maintenance cost over the first year, before considering tax benefits
+- `lifecycle_variable_om_cost_after_tax` Lifecycle variable operations and maintenance cost in present value, after tax. Includes om_cost_per_kwh and om_cost_per_hr_per_kw_rated
+- `year_one_variable_om_cost_before_tax` variable operations and maintenance cost over the first year, before considering tax benefits. Includes om_cost_per_kwh and om_cost_per_hr_per_kw_rated
 - `lifecycle_fuel_cost_after_tax` Lifecycle fuel cost in present value, after tax
 - `year_one_fuel_cost_before_tax` Fuel cost over the first year, before considering tax benefits. Does not include fuel use during outages if using multiple outage modeling.
 - `year_one_fuel_cost_after_tax` Fuel cost over the first year, after considering tax benefits. Does not include fuel use during outages if using multiple outage modeling.
@@ -28,17 +28,13 @@ function add_generator_results(m::JuMP.AbstractModel, p::REoptInputs, d::Dict; _
 
 	GenPerUnitSizeOMCosts = @expression(m, p.third_party_factor * p.pwf_om * sum(m[:dvSize][t] * p.om_cost_per_kw[t] for t in p.techs.gen))
 
-	GenPerUnitProdOMCosts = @expression(m, p.third_party_factor * p.pwf_om * p.hours_per_time_step *
-		sum(m[:dvRatedProduction][t, ts] * p.production_factor[t, ts] * p.s.generator.om_cost_per_kwh
-			for t in p.techs.gen, ts in p.time_steps)
-	)
 	r["size_kw"] = round(value(sum(m[:dvSize][t] for t in p.techs.gen)), digits=2)
 	r["lifecycle_fixed_om_cost_after_tax"] = round(value(GenPerUnitSizeOMCosts) * (1 - p.s.financial.owner_tax_rate_fraction), digits=0)
-	r["lifecycle_variable_om_cost_after_tax"] = round(value(m[:TotalPerUnitProdOMCosts]) * (1 - p.s.financial.owner_tax_rate_fraction), digits=0)
+	r["lifecycle_variable_om_cost_after_tax"] = round((value(m[:TotalGenPerUnitProdOMCosts]) + value(m[:TotalHourlyGenOMCosts])) * (1 - p.s.financial.owner_tax_rate_fraction), digits=0)
 	r["lifecycle_fuel_cost_after_tax"] = round(value(m[:TotalGenFuelCosts]) * (1 - p.s.financial.offtaker_tax_rate_fraction), digits=2)
 	r["year_one_fuel_cost_before_tax"] = round(value(m[:TotalGenFuelCosts]) / p.pwf_fuel["Generator"], digits=2)
 	r["year_one_fuel_cost_after_tax"] = r["year_one_fuel_cost_before_tax"] * (1 - p.s.financial.offtaker_tax_rate_fraction)
-	r["year_one_variable_om_cost_before_tax"] = round(value(GenPerUnitProdOMCosts) / (p.pwf_om * p.third_party_factor), digits=0)
+	r["year_one_variable_om_cost_before_tax"] = round(value(m[:TotalGenPerUnitProdOMCosts] + m[:TotalHourlyGenOMCosts]) / (p.pwf_om * p.third_party_factor), digits=0)
 	r["year_one_fixed_om_cost_before_tax"] = round(value(GenPerUnitSizeOMCosts) / (p.pwf_om * p.third_party_factor), digits=0)
 
 	if !isempty(p.s.storage.types.elec)

test/runtests.jl

@@ -2500,6 +2500,7 @@ else  # run HiGHS tests
             post["PV"]["max_kw"] = 0.0
             post["ElectricStorage"]["max_kw"] = 0.0
             post["Generator"]["min_turn_down_fraction"] = 0.0
+            post["Generator"]["om_cost_per_hr_per_kw_rated"] = 2.0
             finalize(backend(m))
             empty!(m)
             GC.gc()            
@@ -2518,7 +2519,9 @@ else  # run HiGHS tests
             @test r["Financial"]["lifecycle_capital_costs"] ≈ 100*(700+324.235442*(1-0.26)) + other_offgrid_capex_after_tax atol=0.1 # replacement in yr 10 is considered tax deductible
             @test r["Financial"]["initial_capital_costs_after_incentives"] ≈ 700*100 + other_offgrid_capex_after_tax 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 
+            @test r["Financial"]["replacements_present_cost_after_tax"] ≈ 100*(324.235442*(1-0.26)) atol=0.1
+            generator_hours_runtime = sum(x -> x > 0, r["Generator"]["electric_to_load_series_kw"]) + sum(x -> x > 0, r["Generator"]["electric_to_storage_series_kw"])
+            @test r["Generator"]["year_one_variable_om_cost_before_tax"] ≈ generator_hours_runtime * r["Generator"]["size_kw"] * post["Generator"]["om_cost_per_hr_per_kw_rated"] atol=0.1
 
             ## Scenario 3: Fixed Generator that can meet load, but cannot meet load operating reserve requirement
             ## This test ensures the load operating reserve requirement is being enforced