Solar ROI Calculator

Payback period on a solar PV system.

Reviewed by The QuickCalc Editorial Team · Last updated 14 July 2026 · About our methodology

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Enter your details

Total installed cost

Estimated monthly saving

Result

Payback period

4.0 years

Inputs & results at a glance

Updates live as you change the form above.

Item	Type	Value
System cost	Input	R120 000,00
Monthly saving	Input	R2 500,00
Payback	Result	4.0 years

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About this calculator

A solar ROI calculator estimates how many years a solar PV installation will take to pay itself back out of the electricity bill savings it produces. Enter the total installed cost of the system (panels, inverter, batteries if any, installation) and your expected monthly saving on your electricity bill.

The payback is simply Total cost ÷ (Monthly saving × 12). A R150,000 system saving R2,500 per month has a straight payback of 5 years. That figure doesn't account for annual Eskom tariff increases (which shorten the payback) or system degradation and inverter replacement (which lengthen it), so most South African households experience a real payback in the 4–7 year range on a well-sized grid-tied system.

The bigger picture matters too. Solar with batteries removes most load-shedding disruption, which many households effectively pay for through generators, UPS units and lost productivity. Newer inverter-and-battery hybrid systems also enable feeding surplus power back into the grid where the municipality allows it. Get quotes from at least three SAPVIA-accredited installers before committing.

How to use it

1Enter the total system cost. Installed price including panels, inverter, batteries and labour.
2Enter monthly saving. Estimated reduction in your electricity bill after solar.
3Read the payback years. How many years the savings take to recover the cost.

How it works

The calculator divides the total installed cost of your solar PV system by the annualised electricity bill saving it produces (monthly saving × 12) to give a straight-line payback in years.

In reality, Eskom tariff increases (which shorten the payback) and system degradation, inverter replacement, and financing costs (which lengthen it) both apply. Most South African households on well-sized grid-tied systems experience a real payback in the 4–7 year range. Add the intangible value of load-shedding avoidance for a fuller picture.

Formula

Payback years = System cost ÷ (Monthly saving × 12)

System cost = total installed cost; Monthly saving = expected monthly electricity bill reduction.

Worked examples

R120,000 system saving R2,500/month

Payback ≈ 4 years.

R200,000 system saving R3,500/month

Payback ≈ 4.8 years.

Frequently asked questions

What's the payback period on solar in South Africa?

Typically 4–7 years on a well-sized residential grid-tied system, driven by rising Eskom tariffs and load-shedding avoidance value.

Does this include batteries?

It uses whatever total system cost you enter. Battery systems cost more upfront but recover the value of load-shedding avoidance.

What monthly savings should I use?

Estimate your typical electricity bill reduction after solar. A 5 kWp system in Gauteng typically covers 50–70% of an average home's usage.

Should I add the value of no load-shedding?

It's hard to quantify, but many households effectively pay a premium for reliable power — factor that into your decision.

What about maintenance?

PV panels are largely maintenance-free for 20+ years. Inverters typically need replacement at year 8–12; batteries at year 6–10.

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Legal disclaimer

The results produced by this calculator are estimates for general guidance only and do not constitute financial, legal, tax, accounting or professional advice. QuickCalc makes no warranty, express or implied, regarding the accuracy, completeness, reliability or suitability of the information for your specific circumstances.

Calculations may not reflect the latest fees, interest rates, statutory thresholds, exchange rates or regulatory changes. Always confirm figures with a qualified professional (such as a registered financial advisor, attorney, accountant or tax practitioner) and with the relevant institution before making any decision or entering into any agreement.

To the maximum extent permitted by law, QuickCalc and its operators accept no liability for any loss, damage or cost arising from reliance on the output of this tool. By using this calculator you acknowledge and accept these terms.

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