Solar Panel Payback Calculator for France: Self-Consumption

Solar panel payback in France: the 2026 calculation

Annual gain = self-consumed kWh × grid price + exported kWh × feed-in tariff. For a 3 kWp system costing €7,500 in a region yielding 1,150 kWh/kWp, with 65% self-consumption, the tool finds about €462 in year one and a 13.9-year payback at October 2026 French rates.

Method

• Annual output = kWp × solar yield (950 kWh/kWp in the north of France, 1,150 in the centre-west, 1,400 in the south).
• Net investment = cost incl. VAT − grant; the "Official grant" option applies €300/kWp up to 3 kWp, €230/kWp up to 9 kWp and €200/kWp above.
• Each year: saving = self-consumed kWh × grid price (raised by your inflation rate); export income = surplus × feed-in tariff (flat). Output declines by 0.5% a year, never below 80%.
• Payback is interpolated within the year when cumulative gains exceed the net investment; avoided CO₂ is estimated at 0.08 kg per kWh produced.

Example with the default values

3 kWp produce 3,450 kWh; 2,243 kWh are self-consumed and 1,208 kWh exported. At €0.2003/kWh the year-one saving is €449, plus €13 of export income at €0.011/kWh: €462. With 3% inflation, the €7,500 is recovered in 13.9 years and the 25-year net gain is about €8,081. For 6 kWp at €13,000, payback drops to 12.3 years.

What changed in 2026

For grid connection requests filed since 5 June 2026, French surplus power is bought at 1.1 c€/kWh excl. VAT (indexed by 2% a year, not modelled) and investment grants no longer exist, so the grant option is off by default. Its built-in per-kWp amounts are indicative and unverified; only enable it for a project under the former scheme, using the grant actually awarded. With such a low feed-in rate, profitability depends mainly on self-consumption.

Indicative estimate; it does not replace an installer's quote. To measure the effect of a battery, use the dedicated simulator; for a US installation, use the solar ROI calculator with the federal tax credit.

Sources and dates: French order of 1 June 2026 amending the S21 tariff order (Official Journal, 04/06/2026) and photovoltaique.info, summary of the changes (17/06/2026): single tariff and end of grants for requests from 05/06/2026; default grid price = Tarif Bleu Base 3-6 kVA on 01/08/2026, 13.61 c€/kWh excl. tax (CRE deliberation 2026-147, annex B) + €30.85/MWh excise (BOFiP) + 20% VAT = €0.2003/kWh. The 0.08 kg CO₂/kWh factor is an indicative, unverified value. Checked on 14/10/2026.

Frequently Asked Questions

How many years do solar panels take to pay for themselves?

With the default values (3 kWp for €7,500, 65% self-consumption, electricity at €0.2003/kWh), the tool finds 13.9 years. For 6 kWp at €13,000, payback falls to 12.3 years.

What is the French feed-in rate for surplus solar power in 2026?

For grid connection requests filed since 5 June 2026 there is a single rate: 1.1 c€/kWh excl. VAT for systems up to 100 kWp, indexed by 2% a year over 20 years. Contracts signed earlier keep their former rate.

Does the French self-consumption grant still exist?

Not for new requests: the order of 1 June 2026 abolished investment grants from 5 June 2026. The tool therefore leaves the grant option off by default.

How much does 1 kWp of solar produce in France?

The tool uses 950 kWh per kWp per year in the north, 1,150 in the centre-west and 1,400 in the south. A 3 kWp system therefore produces between 2,850 and 4,200 kWh a year.

Is it better to self-consume or sell the surplus?

With a feed-in rate of €0.011/kWh and a grid price of €0.2003/kWh, each self-consumed kWh is worth about 18 times more than an exported one. Shifting loads such as the washing machine or water heater to daytime clearly improves returns.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.