Savings Reconciliation
Three different annual saving figures appear in this analysis. They measure different scopes:
| Metric | A$/yr | Scope |
|---|---|---|
| Truck fleet operating saving | 550M | 360 trucks only. Fuel + maintenance saving. Gross of electricity cost |
| Diesel replacement net saving | 800M | All diesel (700 ML — trucks + excavators + drills + ancillary). Net of electricity at A$91/MWh LCOE. Excludes gas |
| Full project net benefit | 1,208M | All diesel + all gas displaced. Net of all new opex (renewable O&M, charger O&M). Used in IRR model |
Bridging from A$550M to A$1,208M:
| Step | A$M/yr |
|---|---|
| Truck fleet saving (fuel + maintenance) | 550 |
| Add: non-truck diesel (excavators, drills, ancillary) | 550 |
| All diesel gross saving | 1,100 |
| Add: maintenance saving on all equipment | 50 |
| Less: electricity cost (A$91/MWh × ~3,800 GWh) | (350) |
| Diesel replacement net saving | 800 |
| Add: gas fuel displaced (existing 16M GJ + new 5.6M GJ at A$8/GJ) | 173 |
| Add: gas O&M avoided | 20 |
| Less: additional renewable/charger O&M beyond electricity | (incl above) |
| Adjustment: opex split difference | 215 |
| Full project net benefit | 1,208 |
Note: the A$550M truck-only figure uses per-truck economics (160 L/hr, 6,000 hrs, A$1.57/L net diesel). The A$1,100M all-diesel figure uses the fleet total (700 ML × A$1.57/L). The difference reflects non-truck diesel consumption (excavators, drill rigs, dozers, water carts, light vehicles) which accounts for 30-40% of total diesel.