Savings & Payback
Show what a system displaces in fuel and grid spend.
Free to use without an account. A free installer account adds saved work, A4 previews and branded PDF exports.
Savings and payback compares what you spend now on generator fuel, generator maintenance and grid power with the cost of a solar system, then estimates monthly saving, annual saving, five-year saving and payback period.
How the Savings & Payback works
Enter current spending
Use real fuel consumption per hour, hours of generator use, the current fuel price and your average monthly grid bill. Include generator servicing.
Describe the solar system
Enter the installed system cost, expected daily generation and the tariff the solar generation displaces.
Read the payback
The tool combines displaced grid spend with a conservative share of generator spend, then divides system cost by annual saving.
Worked example
A shop running a generator six hours a day
4 litres per hour at ₦1,050, 6 hours a day, ₦25,000 monthly maintenance, ₦35,000 grid spend and a ₦6m system generating 9 kWh a day at a ₦220/kWh tariff.
- About ₦781,000 monthly generator cost
- About ₦606,000 estimated monthly saving
- About ₦7.3m saved per year
- Payback in under a year on these inputs
Assumptions and limits
- Fuel price, tariff and generator hours change. Re-run the figures when any of them move.
- The saving is capped conservatively rather than assuming solar removes every naira of generator spend.
- Payback is not a guarantee. Maintenance, financing cost and battery replacement are not included.
Frequently asked questions
How is solar payback calculated?
The tool divides the estimated system cost by the monthly value of displaced generator fuel and grid spending to estimate how long the system takes to pay for itself.
What costs should I include?
Include the full installed system cost and your current generator fuel, maintenance and grid spending. More accurate inputs produce a more reliable payback estimate.
Are the savings guaranteed?
No. Results are indicative. Actual savings depend on tariff changes, fuel prices, system performance, usage patterns and maintenance.
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Last updated 17 October 2026Maintained by Mishka Energy.
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