Solar panel financial return in 2026: an honest look at the ROI
From 14 to 18 years of payback for a typical household, 8 to 11 years in the best cases. We give you the real figures, the real conditions, and what salespeople do not always tell you.
What “financial return” really means for solar panels
The financial return of a solar installation is its ability to recover over time what it cost to install. Unlike other investments, it does not take the form of a direct income stream, but of savings on your electricity bill and, to a lesser extent, of the sale of surplus generation.
There are two main indicators:
- Payback time (ROI): the number of years needed for cumulative savings to cover the initial installation cost. This is the most intuitive metric.
- The internal rate of return (IRR): the equivalent annual rate of return over the installation's lifespan. Useful for comparing with other financial investments.
Realistic figures for 2026: forget the 7-year promises
Adverts regularly claim a payback period of 7 or 8 years. These figures are technically achievable, but only under very favourable conditions that do not match most households. In practice:
The reference table by capacity
| System size | Cost incl. VAT (5.5% VAT) | Estimated annual saving* | Indicative ROI | Estimated IRR |
|---|---|---|---|---|
| 3 kWp | 6,900–7,800 € | 270–535 €/year | 11–22 years | 1–8 % |
| 6 kWp | 11,200–13,000 € | 535–1,070 €/year | 9–19 years | 2–10 % |
| 9 kWp | 15,000–17,600 € | 800–1,600 €/year | 8–18 years | 3–12 % |
* Annual saving = self-consumed kWh × 0.2001 €/kWh (EDF tarif bleu) + surplus sold × 0.011 €/kWh, with no self-consumption bonus (abolished by the 1 June 2026 arrêté). Generation of 1,030 to 1,550 kWh/kWp/year depending on the city (23 cities, PVGIS), self-consumption rate 40–55%, tariff inflation 3%/year, panel degradation 0.5%/year. Cost: simulator estimate, tiled roof and central inverter at the low end of the range, slate and microinverters at the high end.
Why sales figures are often optimistic
Sales pitches often add up all the favourable assumptions at once: perfect orientation, high self-consumption rate, strong electricity inflation, maximum subsidies. None of these assumptions is guaranteed. Our recommendation: simulate with average assumptions, not maximum ones, to avoid disappointment.
Conditions for an optimal financial return
Certain parameters are decisive in making your investment truly profitable. Here are the main levers, and those you cannot change.
What works in your favour ✓
What can compromise the financial return ✗
What is often forgotten in financial return calculations
Financial return projections rely on several assumptions that deserve to be questioned before signing a quote.
The electricity inflation assumption
Most ROI calculations assume an electricity price rise of 3 to 5% per year. This is a reasonable assumption given recent history, but prices can stagnate or fall, as in the 2015-2020 period. If electricity does not rise, your annual saving grows more slowly and the ROI lengthens.
Performance degradation
Solar panels lose on average 0.3 to 0.5% of their output per year. A panel installed in 2026 will produce about 87% of its initial power in 2051. This is a gradual and predictable decline, but it must be built into projections, which not every salesperson does.
Maintenance and replacement costs
The inverter has a lifespan of 10 to 15 years, shorter than that of the panels. Replacing it costs 600 to 2,000 € depending on the type, to be anticipated in the real ROI calculation. The panels themselves need occasional cleaning but little structural maintenance.
The TURPE for self-generators
Any grid-connected installation exporting surplus is subject to the residential self-generator TURPE grid access charge, set at 26.40 € excl. VAT/year for low-voltage subscriptions ≤ 36 kVA. This modest recurring cost must be included in the 25-year projections.
How to calculate your own payback period
The basic formula is simple, but the input data are crucial:
Net cost = Price incl. VAT − aid (reduced VAT)
Saving = self-consumed kWh × 0.2001 € + surplus × 0.011 €
Worked example: standard household in Lyon, 6 kWp
| Parameter | Value | Note |
|---|---|---|
| Installation price incl. VAT | 13,000 € | Median quote for 6 kWp, Lyon, including the 5.5% VAT rate |
| Self-consumption bonus | 0 € | Abolished since 1 June 2026 |
| Net cost | ~13,000 € | |
| Annual generation | ~6,600 kWh | Lyon, south-facing, 30° |
| Estimated self-consumption rate | 45 % | Partial presence during the day |
| Self-consumed kWh / year | ~2,970 kWh | 6,600 × 45% |
| Self-consumption saving / year | ~594 € | 2,970 × 0.2001 €/kWh |
| Surplus sold / year | ~40 € | 3,630 kWh × 0.011 €/kWh |
| Total saving, year 1 | ~634 € | Excluding inflation and degradation |
| Estimated ROI (no inflation) | ~20.5 years | 13,000 / 634 |
| ROI with 3%/year inflation | ~17 years | Savings growing over time |
This illustrative calculation relies on average assumptions. Our simulator performs this calculation with your actual data (GPS location, consumption, measured orientation) and provides a 25-year projection panel by panel.
Solar versus other investments: an honest comparison
Is it better to invest in solar panels than to put the money elsewhere? The answer depends on your situation, but here are the objective elements.
| Investment | Estimated net return | Duration | Taxation | Risk |
|---|---|---|---|---|
| Solar panels (favourable profile) | 5–8%/year | 25 years | Not taxed (≤ 3 kWp) | Poor match |
| Solar panels (standard profile) | 3–5%/year | 25 years | Not taxed (≤ 3 kWp) | Poor match |
| Livret A (regulated savings account) | 3%/year | Instant access | Tax-free | None |
| Life insurance (euro funds) | 2.5–3.5%/year | 8 years min. | Reduced taxation | Very low |
| SCPI (property investment company) | 4–5%/year | 10 years min. | Taxable (income tax) | Moderate |
| Equities (CAC 40 historical) | ~7%/year | Long term | Taxable (30% flat tax, PFU) | High |
Solar is not a financial investment in the strict sense: it is above all home-improvement spending that generates savings. It nevertheless offers a notable tax advantage for small installations: the income remains exempt from income tax for households whose installation does not exceed 3 kWp, which improves the real net return compared with other taxable investments.
Frequently asked questions about solar financial return
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