Generator vs Battery Operating Cost Comparator
Compare the modeled operating cost of delivered backup electricity from a fuel generator and a battery system. Keep fuel cost, charging electricity, conversion losses and fixed operating costs visible in one calculation.
Compare backup energy cost
Backup operating-cost result
| System | Input energy | Variable cost | Fixed cost | Total cost | Delivered cost/kWh |
|---|
How the comparison works
The generator case uses the entered fuel intensity and fuel price to calculate fuel cost per delivered kilowatt-hour, then adds other variable and fixed costs. The battery case works backward from the required delivered energy by accounting for charging and discharge losses.
Generator variable cost/kWh = Fuel intensity × Fuel price + Other generator cost
Battery charging energy = Delivered energy ÷ (Charge efficiency × Discharge efficiency)
Battery cost = Charging energy × Charging electricity price + Degradation cost + Fixed cost
Why battery input energy can exceed delivered energy
Charging and discharge are not lossless. The battery system therefore requires more upstream electricity than the energy ultimately delivered to the load.
Fixed costs need a comparison basis
A fixed cost has to be allocated to a defined comparison volume. This page spreads the entered fixed cost across the delivered energy entered in the form. For a different operating period, adjust the fixed-cost assumption accordingly.
Important limitations
- Generator fuel intensity is user-entered and can vary strongly with load.
- Battery degradation cost is an economic assumption, not a physical loss.
- Capital cost, replacement timing, maintenance and financing are not automatically annualized.
- Grid charging source characteristics are not evaluated.
FAQs
Does the battery always cost less?
No. Its result depends on charging electricity price, efficiency and degradation assumptions.
Can the charging price be zero?
Yes. Zero can represent free energy for a specific modeled charging case, although the broader system economics may still have costs.
Does generator efficiency matter directly?
Its effect is already reflected in the fuel-use-per-kWh input.
Can this compare capital cost?
Only the fixed comparison costs entered by the user are included. A full lifecycle investment study requires a separate financial model.