Generator vs Solar Cost Calculator
Compare multi-year generator running costs with an off-grid solar purchase.
What this comparison includes
The generator side includes daily fuel and annual maintenance. The solar side uses the entered installed price. The result shows the cost difference across the selected period rather than claiming one technology always wins.
How to use it
Use measured generator fuel consumption at a typical load where possible. Include oil, filters and servicing. Enter a complete solar quote that includes panels, regulator, inverter, battery, protection, wiring and installation.
Useful examples
- Testing whether frequent generator use justifies a larger battery system.
- Comparing a five-year fuel budget with a solar quote.
- Showing how reduced generator hours change the payback picture.
Important limits
The simple solar cost does not include finance, component replacement or lost investment returns. Generator efficiency changes with load. Solar availability changes with weather, shading and season, so professional sizing is still required.
Use measured numbers where possible
Small generators often consume more fuel per kilowatt-hour when lightly loaded. Record litres added and run time across several typical days. For solar, compare usable battery capacity rather than advertised nominal capacity and confirm that surge loads such as pumps, fridges and power tools are supported.
Worked example
A generator using 1.2 litres per hour for five hours daily at $2 per litre costs $12 per day, or $21,900 in fuel over five years. Adding $500 annual maintenance produces $24,400, making a $12,000 solar system appear $12,400 cheaper before solar maintenance or replacement costs.