diff --git a/src/demand_side.jl b/src/demand_side.jl
index faaa358..75fe348 100644
--- a/src/demand_side.jl
+++ b/src/demand_side.jl
@@ -2,7 +2,7 @@ struct DemandSideTechnology{T <: PSY.StaticInjection} <: Technology
     name::String
     available::Bool
     power_systems_type::Type{T}
-    capital_cost::Float64
+    capital_cost::IS.FunctionData
     supplemental_attributes_container::IS.SupplementalAttributesContainer
     time_series_container::IS.TimeSeriesContainer
     internal::InfrastructureSystemsInternal
diff --git a/src/storage.jl b/src/storage.jl
index da92a9d..b187736 100644
--- a/src/storage.jl
+++ b/src/storage.jl
@@ -2,10 +2,10 @@ struct StorageTechnology{T <: PSY.Storage} <: Technology
     name::String
     available::Bool
     power_systems_type::Type{T}
-    capital_cost::Float64
+    capital_cost::IS.FunctionData
     battery_chemistry::String # Implement Chemistry Type Enums in PowerSystems
     prime_mover::PSY.Primer_mover
-    capital_cost::Float64
+    capital_cost::IS.FunctionData
     operational_cost::PSY.OperationalCost
     supplemental_attributes_container::IS.SupplementalAttributesContainer
     time_series_container::IS.TimeSeriesContainer
diff --git a/src/supply.jl b/src/supply.jl
index 00c1598..fe680c4 100644
--- a/src/supply.jl
+++ b/src/supply.jl
@@ -5,7 +5,7 @@ struct SupplyTechnology{T <: PSY.Generator} <: Technology
     fuel::PSY.ThermalFuels
     prime_mover::PSY.Primer_mover
     capacity_factor::Float64
-    capital_cost::Float64
+    capital_cost::IS.FunctionData
     operational_cost::PSY.OperationalCost
     supplemental_attributes_container::IS.SupplementalAttributesContainer
     time_series_container::IS.TimeSeriesContainer
diff --git a/src/transport.jl b/src/transport.jl
index e5eaf1a..06ddcfb 100644
--- a/src/transport.jl
+++ b/src/transport.jl
@@ -2,7 +2,7 @@ struct TransportTechnology{T <: PSY.Device} <: Technology
     name::String
     available::Bool
     power_systems_type::Type{T}
-    capital_cost::Float64
+    capital_cost::IS.FunctionData
     supplemental_attributes_container::IS.SupplementalAttributesContainer
     time_series_container::IS.TimeSeriesContainer
     internal::InfrastructureSystemsInternal