How SwiphtGreen Calculates Your Numbers

We don't think a savings calculator should be a black box.

For the full context behind the real cost of power in Nigeria — fuel rates, grid reliability, and the generator burden — read Why Solar?

Step 1 — Annual power yield

How much electricity your proposed system will actually generate in a year:

Annual Yield (kWh) = Panels × (Panel Wattage ÷ 1000) × Peak Sun Hours × 365 × System Efficiency

We use conservative peak sun hours and a realistic system efficiency factor that accounts for inverter losses, panel derating, and real-world conditions. That means the estimate is based on what your system is likely to produce, not manufacturer best-case numbers.

Step 2 — Annual financial savings

How much that generation is worth, based on what you would otherwise spend for the same energy:

Annual Savings (₦) = Annual Yield (kWh) × Effective Cost per kWh

We do not compare solely to the official grid tariff. Instead, we use a blended effective cost per kWh that reflects the real mix of reliable grid hours and generator-powered hours most households actually use.

Step 3 — System cost (CapEx)

The total cost includes panels, inverter(s), battery storage sized to support roughly 55% of daily generation, and installation. We pull these values from our current pricing sheet rather than a fixed flat estimate.

Step 4 — Payback period

How long it takes for your savings to cover the system cost:

Payback Period (Years) = Total System Cost (₦) ÷ Annual Savings (₦)

Every number in the calculator is grounded in actual prices and performance assumptions that are updated as conditions in Nigeria change, not left stale.

Sources

Nigerian Electricity Regulatory Commission (NERC) — Service-Based Tariff structure and 2026 Band A compensation directives
Guardian Nigeria — "How NERC is exploiting electric consumers with band structure"; "Nigeria's electricity is cheaper than everywhere and that's the problem"
Vanguard News — "Power sector crises: Band regime collapses, DisCos miss delivery targets"
Wikipedia — "Nigerian energy supply crisis"
ThisDayLive — "Nigeria's Electricity Paradox and the Unanswered Question of 2026"
TheCable — "Understanding Nigeria's power challenges"
Energy for Growth Hub — "160 Days in the Dark: Understanding Electricity Unreliability in Nigeria"
Connectnigeria — "How Much Does a Generator Cost in Nigeria in 2026?"
Titanium Power Solutions — "Diesel vs Petrol Generators in Nigeria: Which is Right for You? (2026 Guide)"
Renik Energy — "Solar vs Generator in Nigeria: Which Saves More Money?"
Ze-Gen — "Understanding Nigeria's Fossil Fuel Generator Challenge"
Intelpoint — "Only 2.4% of Nigerians earn above ₦200k per month"
Legit.ng — "Income Gap Widens As New Survey Shows Only 5% Of Nigerians Earn Above N500k Monthly" (citing SEID Nigerian Consumer Outlook Report 2025)
Guardian Nigeria — "What is the 1% Income in Nigeria?"
National Bureau of Statistics (NBS) — household petrol/diesel expenditure data