Solar Resale in France: Why the Economic Model is Changing in 2026

TL;DR — What you need to remember

• Total resale has been abolished for installations ≤ 9 kWp since 2025, and the open-window threshold has moved from 500 to 100 kWp.
• In 2024, France experienced 359 hours of negative prices on the wholesale market—a figure multiplied by 3.5 in two years.
• The surplus feed-in tariff (≈ 4 c€/kWh) is now 4 to 6 times lower than the electricity purchase price (15-25 c€/kWh).
• Managed self-consumption + battery storage (BESS) has become the only model that maximizes the profitability of a corporate solar power plant.

The golden age of resale is over

For fifteen years, the economic model of French photovoltaics relied on a simple equation: produce solar electricity, inject it into the grid, and collect a feed-in tariff guaranteed for 20 years by EDF Obligation d'Achat (OA). This total resale logic, boosted by tariffs up to 60 c€/kWh in the 2010s, fulfilled its purpose: increasing installed capacity from a few hundred MW to 21 GW by the end of 2024, with a target of 75 to 100 GW by 2035 (source : ADEME).

But this industrial success spawned its own paradox. The abundance of solar electricity produced simultaneously by hundreds of thousands of installations caused the value of the photovoltaic kWh to collapse at the exact moment it is injected.

Result: in 2026, reselling your solar surplus to the grid is no longer profitable for the majority of corporate installations. Value creation has shifted behind the meter, towards battery-managed self-consumption..

The new 2026 tariff framework: the gradual death of resale

The S21 tariff order, updated for 2026, sends an unambiguous signal: the State no longer pays for grid injection; it pays for local consumption.

Small installations (≤ 9 kWp): total resale abolished

Since Q3 2025, and confirmed for 2026, installations under 9 kWp can no longer sell 100% of their production. Only self-consumption with surplus sale remains possible, at 4.00 c€/kWh.

The S21 Scale — Q2 2026

• ≤ 9 kWp — Total resale: Ineligible | Surplus sale: 4.00 c€/kWh
• 9 to 36 kWp — Total resale: 8.05 c€/kWh | Surplus sale: 4.73 c€/kWh
• 36 to 100 kWp — Total resale: 7.00 c€/kWh | Surplus sale: 4.73 c€/kWh

Compare this with the electricity purchase price for a business: 15 to 25 c€/kWh once supply, grid fees, and taxes are included (sources : Terre Solaire, Dualsun).

Sizing a plant for resale becomes economically irrational.

The self-consumption premium to compensate

To steer the market towards self-consumption, the State pays an investment premium:

• 140 €/kWp for installations up to 36 kWp
• 60 €/kWp for those from 36 to 100 kWp

Since November 1, 2022, for installations > 9 kWp, this premium is no longer paid all at once: 80% the first year, then 4 × 5% over the following four years.

100-500 kWp: time for the Simplified Call for Tenders (AOS)

Since September 22, 2025, any project > 100 kWp must go through the AOS administered by the CRE. The tariff is no longer imposed by the State: candidates propose their own price (€/MWh), and the lowest bidders win until the called volume is reached.

For the 2nd period of 2026:

• Called volume: 288 MWp
• Ceiling price: 95 €/MWh (any bid above is eliminated)
• Average winning price late 2025: 88.73 €/MWh (≈ 8.87 c€/kWh)

Added to this is a mandatory €10,000 bank guarantee to be deposited upon the grid connection request, seized in case of unjustified abandonment. End of the phantom projects that clogged Enedis.

> 500 kWp: the CRE remuneration supplement

Very large rooftops, carports, and agrivoltaic projects fall under standard CRE calls for tenders. Energy is sold on the wholesale market via an aggregator, and the State pays a supplement if the captured price is below the reference tariff.

Scoring out of 100 points:

• Proposed price: 70 points
• Carbon impact (ECS): 25 points — eliminating ceiling at 740 kg CO₂eq/kWp, maximum score at ≤ 420 kg CO₂eq/kWp
• Participatory governance: 2 or 5 points

Targeted winning tariffs for 2026: 85-90 €/MWh for rooftops, 110-118 €/MWh for parking carports (source : CRE).

Solar cannibalization: when abundance destroys value

On the wholesale market, prices are formed by merit order: production means are called upon by increasing marginal cost. Solar, with a marginal cost close to zero, is always called first.

However, most of the European production is concentrated between 12 PM and 4 PM, which is not when demand is at its peak. When this massive production exceeds the residual demand, prices collapse—and even cross into negative territory (sources : Opera Énergie, Virta).

The telling figures

• 2022 — Negative price hours in France: 102
• 2024 — Negative price hours in France: 359 (+ 550 additional hours at zero price)
• H1 2025 — Negative price hours in France: 8% of total time

Over the same period, the average daily spread between low and high prices doubled, going from 27 €/MWh in 2019 to 75 €/MWh in 2024—or 140% of the average energy price.

The CRE's response: end of immunity

For new remuneration supplement contracts:

• Shift to a 15-minute settlement time step.
• Gradual abolition of the "negative prices premium".
• If prices are negative for more than 15 cumulative hours per year, compensation is only paid if the installation physically stops injecting into the grid.

In practical terms, solar producers must now equip themselves with control systems capable of instantly decoupling the plant from the Enedis grid. The cannibalization risk is transferred from the State to the developer (source : CRE — délibération ISP15).

The paradigm shift: self-consuming rather than reselling

With a resale tariff at 4 c€/kWh against a purchase cost at 20 c€/kWh, the tradeoff is clear. Every self-consumed kWh is worth 4 to 6 times more than a resold kWh.

Self-consumption does not generate direct revenues—it avoids expenses. And it avoids not only the cost of the energy molecule itself, but also:

• The TICFE (excise duties), structurally trending upwards.
• Grid routing fees (TURPE)—which will increase by about 10% over 2025-2028.
• Suppliers' margins, now fully exposed to the free market since the end of ARENH (December 2025).

It is, in practice, a financial shield against electricity market volatility (source : ADEME — avis autoconsommation, janvier 2025).

Why PV alone is not enough

A solar installation without a battery, conservatively sized to avoid midday surpluses, struggles to exceed a 15-20% coverage rate on an industrial site. The desynchronization between daytime production and consumption profiles (morning, 3-shift schedules, evening peaks) mechanically limits the benefit.

If you try to force the rate by oversizing the panels, you generate massive midday surpluses that are:

• Either resold at 4 c€/kWh — value destruction.
• Or curtailed by the inverter — pure loss.

This is exactly where battery storage changes the equation.

Battery storage (BESS): the new profitable asset

A modern BESS system is not a simple reservoir. It is a controllable energy asset that reacts in milliseconds to price signals, weather variations, and transmission grid frequency commands.

Budget-wise, the industrial investment is currently between €250,000 and €350,000 per installed MWh (cells, power electronics, fire safety, transformer).

The golden rule: co-dimensioning

Concrete use case — industrial site consuming 5 GWh/year:

• PV alone: PV capacity: 1 MWp | Storage: — | Coverage rate: ≈ 17%
• Co-dimensioning: PV capacity: 2 MWp | Storage: 1.5 MW / 3 MWh | Coverage rate: ≈ 33%

The overall IRR remains between 15% and 20%. The return on investment for the solar part is between 5 and 7 years; the storage block alone, actively operated, can show an ROI of 3 to 4 years thanks to market volatility.

The LCOS equation

The LCOS (Levelized Cost of Storage) is the discounted cost of the kWh passing through the battery over its entire lifecycle (≈ 15 years for lithium-ion).

The battery is profitable if:

Price of electricity drawn from the grid > Surplus sale price + LCOS

In 2026, this equation is largely favorable to storage in the majority of industrial and commercial cases.

Value stacking: six levers of profitability

Self-consumption is only the base layer. A well-managed BESS stacks several value streams in parallel.

1. Spot market arbitrage: Charge at night or during the solar peak (low/negative prices), discharge during morning and evening peaks. For a factory consuming 25 GWh/year, an investment of about €1M generates ≈ €350,000 in annual gains.
2. TURPE peak/off-peak shifting: Short Utilization High Voltage (HTA) peak hours cost 60 €/MWh compared to 23 €/MWh in off-peak hours. Shifting consumption through the battery saves up to 37 €/MWh on transmission alone.
3. D341-9 abatement for electro-intensives: VHV (HTB) sites consuming > 10 GWh/year can obtain up to 74% TURPE abatement if they maintain an off-peak utilization rate > 0.44. The BESS guarantees this threshold.
4. Peak shaving: The battery injects its own energy during sudden power spikes, durably lowering the subscribed power and avoiding Enedis excess penalties.
5. RTE grid services + capacity mechanism: Primary/secondary frequency reserves, load shedding on winter PP1 days: direct revenues and recurring savings (≈ 30 €/MWh on capacity).
6. Process protection + reactive power: Complementing an UPS, the battery protects against micro-outages (critical in plastics, semiconductors). Its bidirectional inverters also manage the power factor (cos φ) and avoid penalties for poor power factor.

During the 2022 energy crisis, a 5 MWh battery would have saved a factory €500,000 in a single year thanks to daily spreads > 350 €/MWh.

Circular economy: second-life batteries are game-changers

The final link in this mutation is the origin of the batteries. First-life BESS (new cells) are highly CO₂-emitting during manufacturing, and their CAPEX remains high.

This is precisely the niche where Battwoo positions itself: repurposing EV traction batteries at the end of their automotive use (but which still retain 80 to 90% of their capacity) into industrial stationary storage systems. This approach makes it possible to:

• Divide by 4 the structural carbon impact of a storage project.
• Significantly lower the acquisition CAPEX compared to new cells.
• Secure a European value chain, independent of massive imports.

To discover how it works in practice: our solution · our expertise · our case-studies.

Key takeaways

• Today: Self-consume the maximum (vs. Resell 100% of production)
• Today: Competitive AOS + remuneration supplement (vs. 20-year guaranteed tariff by EDF OA)
• Today: PV plant + Controllable BESS (vs. Passive PV plant)
• Today: Cost avoidance: energy + TURPE + taxes (vs. Resale revenues)
• Today: Second-life batteries / circular economy (vs. New cells)

Corporate photovoltaics are not dead—they have changed nature. The right project in 2026 is no longer a plant that produces, it is an energy asset that manages, stores, and arbitrages.

FAQ

Is reselling solar electricity still profitable in 2026?

For installations > 36 kWp, yes, provided you win an AOS or a CRE tender. For small installations (< 9 kWp), total resale no longer exists: only self-consumption with surplus sale at 4 c€/kWh remains possible—which makes resale alone structurally unprofitable.

Why are feed-in tariffs dropping?

Because the cost of photovoltaic equipment has plummeted by over 80% in ten years. S21 tariffs are calibrated to offer reasonable profitability without creating windfall profits, so they mechanically follow the drop in CAPEX.

What is solar cannibalization?

It is the phenomenon where massive midday solar production causes the wholesale price of electricity to collapse during the hours it is produced. In concrete terms, solar producers are the victims of their own abundance.

Why are there negative prices on the electricity market?

When supply durably exceeds demand and grid storage capacities are saturated, producers prefer to pay to offload their electricity rather than shut down their power plants (nuclear, thermal) which would cost more to restart.

Is a stationary solar battery profitable for a business?

Yes, in the vast majority of industrial and commercial cases. The ROI of a well-managed storage unit is between 3 and 4 years, and the overall IRR of a PV + BESS project is between 15% and 20%.

What is a second-life battery?

It is a traction battery (from an electric vehicle at the end of its automotive life) repurposed for stationary use. It divides the project's carbon impact by 4.

Does my site need to be large for storage to be profitable?

No. As soon as a site consumes enough electricity during expensive hours (morning/evening peaks, post-ARENH, exposure to the free market), the LCOS calculation becomes favorable. It is the usage profile that matters, not just the size.

Planning a solar or storage project?

The energy ecosystem has changed. A photovoltaic project designed in 2020 no longer has the same profitability today, and a project designed without a battery leaves a significant amount of value on the table. Battwoo supports industrial, commercial, and agricultural businesses in sizing, installing, and managing their second-life battery storage systems.

→ Request a free audit of your project

Sources

• ADEME — Énergies renouvelables, flexibilité, stockage et autoconsommation (janvier 2025)
• ADEME — Avis sur l'autoconsommation photovoltaïque (janvier 2025)
• ADEME — Données photovoltaïque
• CRE — Propositions pour optimiser le développement des grandes installations photovoltaïques
• CRE — Délibération sur le pas de temps 15 minutes
• RTE — Bilan électrique 2025 : prix
• Terre Solaire — Tarifs d'achat photovoltaïque 2026
• Dualsun — Tarif de rachat électricité photovoltaïque 2026
• ECOinfos — Tarif rachat photovoltaïque EDF OA 2026
• Opera Énergie — Prix négatifs de l'électricité : définition, impacts & opportunités
• Virta — Électricité à prix négatif : comprendre, anticiper, saisir les opportunités