LCOX calculation with strict enforcement of units

Cargo.toml

@@ -31,6 +31,7 @@ indexmap = "2.9.0"
 human-panic = "2.0.2"
 clap-markdown = "0.1.5"
 platform-info = "2.0.5"
+derive_more = "0.99"
 
 [dev-dependencies]
 regex = "1.11.1"

src/lib.rs

@@ -7,13 +7,15 @@ pub mod commodity;
 pub mod id;
 pub mod input;
 pub mod log;
+pub mod metrics;
 pub mod model;
 pub mod output;
 pub mod process;
 pub mod region;
 pub mod settings;
 pub mod simulation;
 pub mod time_slice;
+pub mod units;
 pub mod year;
 
 #[cfg(test)]

src/metrics.rs

@@ -0,0 +1,65 @@
+#![allow(missing_docs)]
+
+use crate::units::*;
+
+/// Calculates the capital recovery factor (CRF) for a given lifetime and discount rate.
+///
+/// The CRF is used to annualize capital costs over the lifetime of an asset.
+pub fn capital_recovery_factor(lifetime: IYear, discount_rate: Dimensionless) -> Dimensionless {
+    if lifetime == IYear(0) {
+        return Dimensionless(0.0);
+    }
+    if discount_rate == Dimensionless(0.0) {
+        return Dimensionless(1.0 / lifetime.0 as f64);
+    }
+    let factor = (Dimensionless(1.0) + discount_rate).powi(lifetime.0 as i32);
+    (discount_rate * factor) / (factor - Dimensionless(1.0))
+}
+
+/// Calculates the annual capital cost for a technology
+pub fn annual_capital_cost(
+    capital_cost: MoneyPerCapacity,
+    capacity: Capacity,
+    lifetime: IYear,
+    discount_rate: Dimensionless,
+) -> MoneyPerYear {
+    let crf = capital_recovery_factor(lifetime, discount_rate);
+    let total_capital_cost = capital_cost * capacity * crf;
+    let annual_capital_cost = total_capital_cost * crf;
+    MoneyPerYear(annual_capital_cost.0) // this is an annualized quantity, so we return it as such
+}
+
+/// Calculates the annual fixed operating cost for a technology
+pub fn annual_fixed_operating_cost(
+    fixed_operating_cost: MoneyPerCapacityPerYear,
+    capacity: Capacity,
+) -> MoneyPerYear {
+    fixed_operating_cost * capacity
+}
+
+/// Calculates the annual fixed costs for a technology
+///
+/// This is the sum of the annual capital cost and the annual fixed operating cost.
+pub fn annual_fixed_costs(
+    capital_cost: MoneyPerCapacity,
+    capacity: Capacity,
+    lifetime: IYear,
+    discount_rate: Dimensionless,
+    fixed_operating_cost: MoneyPerCapacityPerYear,
+) -> MoneyPerYear {
+    let annual_capital_cost = annual_capital_cost(capital_cost, capacity, lifetime, discount_rate);
+    let annual_fixed_operating_cost = annual_fixed_operating_cost(fixed_operating_cost, capacity);
+    annual_capital_cost + annual_fixed_operating_cost
+}
+
+/// Calculates the annual variable cost for a technology
+pub fn annual_variable_cost(
+    variable_operating_cost: MoneyPerActivity,
+    capacity: Capacity,
+    cap2act: ActivityPerCapacity,
+    utilization: Dimensionless,
+) -> MoneyPerYear {
+    let capacity_a = capacity * cap2act;
+    let annual_variable_cost = variable_operating_cost * capacity_a * utilization;
+    MoneyPerYear(annual_variable_cost.0) // this is an annualized quantity, so we return it as such
+}