Best Solar Design Software France: 2026 Guide

French solar design changed shape on 5 June 2026. The revised S21 tariff arrêté abolished the prime à l’autoconsommation for new installations and cut the surplus buyback rate to 1.1 centimes per kWh excluding tax. Against a regulated retail price many times higher, the value of an exported kilowatt-hour collapsed by an order of magnitude. Every design habit built over the previous decade, filling the available roof, treating surplus as revenue, positioning storage as an optional extra, is now wrong. This guide covers what French design software has to do under the new regime, and which tools do it.

Short version. The best solar design software for French installers in 2026 is SurgePV, because the reform turned French design into an hourly self-consumption and storage optimisation problem, and SurgePV runs 8,760-hour simulation with battery dispatch against French tariffs. PVsyst remains the bankable reference for large ground-mount. PV*SOL is credible for European residential detail. Aurora assumes US net metering, which France has never operated.

For the quoting side see our best solar proposal software France guide, and the global best solar design software ranking for the category without the local lens.

What The S21 Reform Actually Changes For Design

The old regime paid an upfront bonus per kilowatt installed and bought surplus at a rate that made export genuinely worthwhile. Both of those pushed in the same direction: install more capacity. The bonus scaled with size and the surplus had a buyer.

The new regime removes the bonus and prices surplus at 1.1 centimes. Nothing pushes toward capacity any more.

The last row is the design problem in one line. Capacity beyond what the household consumes during daylight now generates energy worth roughly a twentieth of what the same household pays to import. It is not quite worthless, but it is close enough that a designer who keeps adding modules is adding cost without adding value.

Self-Consumption Is Now The Whole Calculation

If surplus is worth 1.1 centimes and imported energy costs many times that, then the only number that matters is what proportion of generation the household actually uses at the moment it is generated.

That proportion is not a property of the array. It is a property of the load curve, and it varies enormously between households. A family working from home with an electric vehicle and a heat pump may self-consume most of what a modest array produces. A household that leaves at eight and returns at six may self-consume a third of it.

Two systems with identical hardware on identical roofs therefore have quite different economics, and the difference is invisible to any tool that compares annual generation against annual consumption. Annual totals will happily show a household “covering” its usage while in reality it exports at midday and imports all evening.

This is why hourly simulation stopped being a nicety in France. The design question is now specifically “in each of 8,760 hours, does generation meet load?” and only a tool that answers that question hour by hour can size the array or justify the battery.

Storage Moved From Upsell To Core Design

The battery arithmetic under the new regime is unusually favourable, and it is worth stating plainly because many French installers built their instincts under the old one.

Every kilowatt-hour a battery shifts from midday surplus to evening consumption converts energy worth 1.1 centimes into energy worth the full retail import price. Under the old tariff a battery competed against a decent export rate, so the spread it captured was modest. Now it captures nearly the entire retail price.

That does not make storage automatically correct. Battery cost, cycle life and the actual shiftable volume still decide it, and on a household with genuinely low evening demand there may be little to shift. But the calculation now starts from a much better place, and it is a calculation rather than a guess. Sizing a battery requires simulating dispatch against the hourly load and generation profiles together, which is a capability worth checking for specifically when evaluating tools.

The Rest Of The French Requirement Set

NF C 15-712-1 is the reference standard for photovoltaic installations connected to the public network, sitting alongside NF C 15-100 for the general low-voltage installation. A Consuel attestation of conformity is required before the connection is commissioned, and a design that has not been built against these will surface the problem at the worst point in the programme.

Enedis connection timing is now commercially significant in a way it was not before. The 5 June 2026 cutoff was defined by connection request validation, so the installed base splits into two populations with different economics for the next twenty years.

Regional irradiance variation matters. France spans a wide latitude range and the difference between Lille and Marseille is large enough to change the self-consumption balance, not just the total yield. Use site weather data.

The Six Platforms French Installers Should Evaluate

1. SurgePV, the all-in-one pick

8,760-hour simulation with hourly self-consumption analysis, battery dispatch modelling, French tariff and standards libraries, AI 3D roof modelling from satellite imagery, and white-label proposals with e-signature in 9 languages including French, generated from the same design record. $1,299 to $1,899 per user per year.

2. PVsyst

The bankable reference for large ground-mount and commercial projects, frequently named by lenders and offtakers. Strong simulation, no proposal layer, and French incentive logic has to be applied manually. See our PVsyst alternative review.

3. PV*SOL

Well established in European residential and small commercial work, with good component libraries and credible shading handling. Desktop-based, and its self-consumption tooling is solid. Our PV*SOL alternative guide covers the trade-offs.

4. OpenSolar

Free and quick for residential layout and a fast customer-facing document. Weaker on the hourly self-consumption and storage modelling that now decides French sizing. See our OpenSolar alternative comparison.

5. Aurora Solar

Strong residential design built around US net metering, which France has never had and is now further from than ever. Poor fit despite the quality. See our Aurora Solar alternative comparison.

6. Spreadsheets plus a generic yield tool

Still common in smaller French practices. Flexible, and the most likely place a pre-reform tariff assumption survives untouched into a 2026 quote.

France Solar Design Software Comparison

Worked Example: 6 kWp Near Lyon, Old Rules Versus New

An illustrative calculation showing how the reform changes the recommended design, not a specific customer project. Inputs: 6 kWp array, roughly 7,200 kWh annual generation, household consumption 4,000 kWh, 35% self-consumption without storage.

The 4,680 kWh of exported energy now earns roughly the price of a restaurant meal for the year. That is the whole argument for redesigning.

Two responses follow, and a good tool lets you compare them rather than assert one. Reducing the array to something closer to daytime load cuts cost while losing almost no value, because the energy removed was the near-worthless kind. Alternatively, keeping 6 kWp and adding storage lifts self-consumption toward 70% or more, converting several thousand kilowatt-hours a year from 1.1 centimes to full retail. Which one wins depends on battery cost against the value of the shifted energy, and on how much evening demand the household actually has.

What is no longer defensible is the third option: quoting 6 kWp with no storage and presenting the export as revenue.

Who Should Choose What

• Choose SurgePV if you need hourly self-consumption analysis, battery dispatch modelling and post-reform tariff logic in one tool.
• Choose PVsyst where a lender or offtaker names it on large ground-mount, paired with separate quoting.
• Choose PV*SOL if your team is desktop-based and works mostly on European residential with detailed component modelling.
• Avoid Aurora and pre-reform spreadsheet templates. Both will size French systems on logic that stopped applying in June 2026.

The Bottom Line

France did not adjust its solar incentives in June 2026. It removed them, and the design brief changed with them.

• Stop sizing to the roof. Surplus earns 1.1 centimes, so capacity beyond the daytime load curve is close to free energy for the grid.
• Model self-consumption hourly. Annual totals will tell you a household covers its usage while it exports at noon and imports all evening.
• Treat storage as a design decision. It now captures nearly the full retail spread, which is a far better case than it had a year ago.