Merge pull request #491 from NREL/add-cost-constraint

Option to constrain initial CAPEX

Author: adfarth

CHANGELOG.md

@@ -25,6 +25,9 @@ Classify the change according to the following categories:
     ### Deprecated
     ### Removed
 
+## add-cost-constraint
+### Added
+- Added new fields `min_initial_capital_costs_before_incentives` and `max_initial_capital_costs_before_incentives` which, when floating-point numbers are provided, provide upper and lower bounds on initial capital costs for all technologies.  When active, this also warns the user that the problem may become infeasible when performed in combination with resilience requirements.
 
 ## fix-pbi
 ### Fixed

src/constraints/cost_curve_constraints.jl

@@ -6,7 +6,7 @@ There are two situations under which we add binary constraints to the model in o
 for a technology:
     1. When a technology has tax or investment incentives with upper capacity limits < tech.max_kw
         - first segment(s) have lower slope than last segment
-    2. When a technology has multiple cost/size pairs (not implemented yet, used for CHP in v1)
+    2. When a technology has multiple cost/size pairs
         - we interpolate the slope between the cost/size points, typically with economies of scale pricing
 We used to use cost curve segments for when a technology has a non-zero existing_kw by setting the first segment to a
 zero cost (and slope) from zero kw to the existing_kw. Instead, we now have dvPurchaseSize >= dvSize - existing_kw.
@@ -65,4 +65,154 @@ function add_cost_curve_vars_and_constraints(m, p; _n="")
     @constraint(m, [t in p.techs.segmented],
         m[Symbol("dvPurchaseSize"*_n)][t] == m[Symbol("dvSize"*_n)][t] - p.existing_sizes[t]
     )
+end
+
+function add_capex_constraints(m, p; _n="")
+    @warn "Adding capital costs constraints. These may cause an infeasible problem in some cases, particularly for resilience runs."
+    if (!isnothing(p.s.financial.min_initial_capital_costs_before_incentives) && !isnothing(p.s.financial.max_initial_capital_costs_before_incentives)
+            && p.s.financial.min_initial_capital_costs_before_incentives > p.s.financial.max_initial_capital_costs_before_incentives)
+        throw(@error("Minimum required capital cost is larger than maximum required capital cost - this problem is infeasible.")) 
+    end
+    if !isnothing(p.s.financial.min_initial_capital_costs_before_incentives)
+        @constraint(m,
+            m[:InitialCapexNoIncentives] >= p.s.financial.min_initial_capital_costs_before_incentives
+        )
+    end
+    if !isnothing(p.s.financial.max_initial_capital_costs_before_incentives)
+        @constraint(m,
+            m[:InitialCapexNoIncentives] <= p.s.financial.max_initial_capital_costs_before_incentives
+        )
+    end
+end
+
+function initial_capex_no_incentives(m::JuMP.AbstractModel, p::REoptInputs; _n="")
+    m[:InitialCapexNoIncentives] = JuMP.GenericAffExpr{Float64, JuMP.VariableRef}(0.0) # Avoids MethodError
+    
+    add_to_expression!(m[:InitialCapexNoIncentives], 
+        p.s.financial.offgrid_other_capital_costs - m[Symbol("AvoidedCapexByASHP"*_n)] - m[Symbol("AvoidedCapexByGHP"*_n)]
+    )
+
+    if !isempty(p.techs.gen) && isempty(_n)  # generators not included in multinode model
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            p.s.generator.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)]["Generator"]
+        )
+    end
+
+    if !isempty(p.techs.pv)
+        for pv in p.s.pvs
+            add_to_expression!(m[:InitialCapexNoIncentives], 
+                pv.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)][pv.name]
+            )
+        end
+    end
+
+    for b in p.s.storage.types.elec
+        if p.s.storage.attr[b].max_kw > 0
+            add_to_expression!(m[:InitialCapexNoIncentives], 
+                p.s.storage.attr[b].installed_cost_per_kw * m[Symbol("dvStoragePower"*_n)][b]
+                + p.s.storage.attr[b].installed_cost_per_kwh * m[Symbol("dvStorageEnergy"*_n)][b]
+            )
+        end
+    end
+
+    for b in p.s.storage.types.thermal
+        if p.s.storage.attr[b].max_kw > 0
+            add_to_expression!(m[:InitialCapexNoIncentives], 
+                p.s.storage.attr[b].installed_cost_per_kwh * m[Symbol("dvStorageEnergy"*_n)][b]
+            )
+        end
+    end
+
+    if "Wind" in p.techs.all
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            p.s.wind.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)]["Wind"]
+        )
+    end
+
+    if "CHP" in p.techs.all
+        m[:CHPCapexNoIncentives] = JuMP.GenericAffExpr{Float64, JuMP.VariableRef}()
+        cost_list = p.s.chp.installed_cost_per_kw
+        size_list = p.s.chp.tech_sizes_for_cost_curve
+
+        t="CHP"
+        if t in p.techs.segmented
+            # Use "no incentives" version of p.cap_cost_slope and p.seg_yint
+            cost_slope_no_inc = [cost_list[1]]
+            seg_yint_no_inc = [0.0]
+            for s in range(2, stop=length(size_list))
+                tmp_slope = round((cost_list[s] * size_list[s] - cost_list[s-1] * size_list[s-1]) /
+                                (size_list[s] - size_list[s-1]), digits=0)
+                tmp_y_int = round(cost_list[s-1] * size_list[s-1] - tmp_slope * size_list[s-1], digits=0)
+                append!(cost_slope_no_inc, tmp_slope)
+                append!(seg_yint_no_inc, tmp_y_int)
+            end
+            append!(cost_slope_no_inc, cost_list[end])
+            append!(seg_yint_no_inc, 0.0)
+
+            add_to_expression!(m[:CHPCapexNoIncentives],
+                sum(cost_slope_no_inc[s] * m[Symbol("dvSegmentSystemSize"*t)][s] + 
+                    seg_yint_no_inc[s] * m[Symbol("binSegment"*t)][s] for s in 1:p.n_segs_by_tech[t])
+            )
+        else
+            add_to_expression!(m[:CHPCapexNoIncentives], cost_list * m[Symbol("dvPurchaseSize"*_n)]["CHP"])
+        end
+        if p.s.chp.supplementary_firing_capital_cost_per_kw > 0
+            add_to_expression!(m[:CHPCapexNoIncentives], 
+                p.s.chp.supplementary_firing_capital_cost_per_kw * m[Symbol("dvSupplementaryFiringSize"*_n)]["CHP"]
+            )
+        end
+        add_to_expression!(m[:InitialCapexNoIncentives], m[:CHPCapexNoIncentives])
+    end
+
+    if "SteamTurbine" in p.techs.all
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            p.s.steam_turbine.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)]["SteamTurbine"]
+        )
+    end
+
+    if "Boiler" in p.techs.all
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            p.s.boiler.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)]["Boiler"]
+        )
+    end
+
+    if "AbsorptionChiller" in p.techs.all
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            p.s.absorption_chiller.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)]["AbsorptionChiller"]
+        )
+    end
+
+    if !isempty(p.s.ghp_option_list)
+        for option in enumerate(p.s.ghp_option_list)
+            if option[2].heat_pump_configuration == "WSHP"
+                add_to_expression!(m[:InitialCapexNoIncentives], 
+                    option[2].installed_cost_per_kw[2]*option[2].heatpump_capacity_ton*m[Symbol("binGHP"*_n)][option[1]]
+                )
+            elseif option[2].heat_pump_configuration == "WWHP"
+                add_to_expression!(m[:InitialCapexNoIncentives], 
+                    (option[2].wwhp_heating_pump_installed_cost_curve[2]*option[2].wwhp_heating_pump_capacity_ton + option[2].wwhp_cooling_pump_installed_cost_curve[2]*option[2].wwhp_cooling_pump_capacity_ton)*m[Symbol("binGHP"*_n)][option[1]]
+                )
+            else
+                @warn "Unknown heat pump configuration provided, excluding GHP costs from initial capital costs."
+            end
+        end
+    end
+
+    if "ASHPSpaceHeater" in p.techs.all
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            p.s.ashp.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)]["ASHPSpaceHeater"]
+        )
+    end
+
+    if "ASHPWaterHeater" in p.techs.all
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            p.s.ashp_wh.installed_cost_per_kw * m[Symbol("dvPurchaseSize"*_n)]["ASHPWaterHeater"]
+        )
+    end
+
+    if !isempty(p.s.electric_utility.outage_durations)
+        add_to_expression!(m[:InitialCapexNoIncentives], 
+            m[:mgTotalTechUpgradeCost] + m[:dvMGStorageUpgradeCost]
+        )
+    end
 end

src/core/financial.jl

@@ -19,7 +19,9 @@
     macrs_five_year::Array{Float64,1} = [0.2, 0.32, 0.192, 0.1152, 0.1152, 0.0576],  # IRS pub 946
     macrs_seven_year::Array{Float64,1} = [0.1429, 0.2449, 0.1749, 0.1249, 0.0893, 0.0892, 0.0893, 0.0446],
     offgrid_other_capital_costs::Real = 0.0, # only applicable when `off_grid_flag` is true. Straight-line depreciation is applied to this capex cost, reducing taxable income.
-    offgrid_other_annual_costs::Real = 0.0 # only applicable when `off_grid_flag` is true. Considered tax deductible for owner. Costs are per year. 
+    offgrid_other_annual_costs::Real = 0.0 # only applicable when `off_grid_flag` is true. Considered tax deductible for owner. Costs are per year.
+    min_initial_capital_costs_before_incentives::Union{Nothing,Real} = nothing # minimum up-front capital cost for all technologies, excluding replacement costs and incentives.
+    max_initial_capital_costs_before_incentives::Union{Nothing,Real} = nothing # maximum up-front capital cost for all technologies, excluding replacement costs and incentives.
     # Emissions cost inputs
     CO2_cost_per_tonne::Real = 51.0,
     CO2_cost_escalation_rate_fraction::Real = 0.042173,
@@ -62,6 +64,8 @@ struct Financial
     macrs_seven_year::Array{Float64,1}
     offgrid_other_capital_costs::Float64
     offgrid_other_annual_costs::Float64
+    min_initial_capital_costs_before_incentives::Union{Nothing,Real}
+    max_initial_capital_costs_before_incentives::Union{Nothing,Real}
     CO2_cost_per_tonne::Float64
     CO2_cost_escalation_rate_fraction::Float64
     NOx_grid_cost_per_tonne::Float64
@@ -94,6 +98,8 @@ struct Financial
         macrs_seven_year::Array{<:Real,1} = [0.1429, 0.2449, 0.1749, 0.1249, 0.0893, 0.0892, 0.0893, 0.0446],
         offgrid_other_capital_costs::Real = 0.0, # only applicable when `off_grid_flag` is true. Straight-line depreciation is applied to this capex cost, reducing taxable income.
         offgrid_other_annual_costs::Real = 0.0, # only applicable when `off_grid_flag` is true. Considered tax deductible for owner.
+        min_initial_capital_costs_before_incentives::Union{Nothing,Real} = nothing,
+        max_initial_capital_costs_before_incentives::Union{Nothing,Real} = nothing,
         # Emissions cost inputs
         CO2_cost_per_tonne::Real = 51.0,
         CO2_cost_escalation_rate_fraction::Real = 0.042173,
@@ -191,6 +197,8 @@ struct Financial
             macrs_seven_year,
             offgrid_other_capital_costs,
             offgrid_other_annual_costs,
+            min_initial_capital_costs_before_incentives,
+            max_initial_capital_costs_before_incentives,
             CO2_cost_per_tonne,
             CO2_cost_escalation_rate_fraction,
             NOx_grid_cost_per_tonne,

src/core/reopt.jl

@@ -398,7 +398,7 @@ function build_reopt!(m::JuMP.AbstractModel, p::REoptInputs)
         @warn "Adding binary variable(s) to model cost curves"
         add_cost_curve_vars_and_constraints(m, p)
         for t in p.techs.segmented  # cannot have this for statement in sum( ... for t in ...) ???
-            m[:TotalTechCapCosts] += p.third_party_factor * (
+			m[:TotalTechCapCosts] += p.third_party_factor * (
                 sum(p.cap_cost_slope[t][s] * m[Symbol("dvSegmentSystemSize"*t)][s] + 
                     p.seg_yint[t][s] * m[Symbol("binSegment"*t)][s] for s in 1:p.n_segs_by_tech[t])
             )
@@ -477,6 +477,12 @@ function build_reopt!(m::JuMP.AbstractModel, p::REoptInputs)
 		end
 	end
 
+	# Get CAPEX expressions and optionally constrain CAPEX 
+	initial_capex_no_incentives(m, p)
+	if !isnothing(p.s.financial.min_initial_capital_costs_before_incentives) || !isnothing(p.s.financial.max_initial_capital_costs_before_incentives)
+		add_capex_constraints(m, p)
+	end
+
 	#################################  Objective Function   ########################################
 	@expression(m, Costs,
 		# Capital Costs

src/results/chp.jl

@@ -21,6 +21,7 @@
 - `year_one_standby_cost_after_tax` CHP standby charges in year one, after tax
 - `lifecycle_standby_cost_after_tax` Present value of all CHP standby charges, after tax.
 - `thermal_production_series_mmbtu_per_hour`  
+- `initial_capital_costs` Initial capital costs of the CHP system, before incentives [\$]
 
 !!! note "'Series' and 'Annual' energy outputs are average annual"
 	REopt performs load balances using average annual production values for technologies that include degradation. 
@@ -137,7 +138,7 @@ function add_chp_results(m::JuMP.AbstractModel, p::REoptInputs, d::Dict; _n="")
 	r["year_one_standby_cost_before_tax"] = round(value(m[Symbol("TotalCHPStandbyCharges")]) / p.pwf_e, digits=0)
 	r["year_one_standby_cost_after_tax"] = r["year_one_standby_cost_before_tax"] * (1 - p.s.financial.offtaker_tax_rate_fraction)
 	r["lifecycle_standby_cost_after_tax"] = round(value(m[Symbol("TotalCHPStandbyCharges")]) * (1 - p.s.financial.offtaker_tax_rate_fraction), digits=0)
-
+	r["initial_capital_costs"] = round(value(m[Symbol("CHPCapexNoIncentives")]), digits=2)
 
     d["CHP"] = r
     nothing