Negative electricity prices: the new normal in France

Negative electricity prices are no longer an exception in France. In the first half of 2026, the wholesale price fell below zero for 407 hours, according to RTE's half-year report (in French). That is about 10% of the time.

In practice, midday electricity loses its value while evening electricity keeps it. For a business, shifting energy from midday to the evening is no longer a nice-to-have. It is simple economics.

What is a negative electricity price?

A negative electricity price is a wholesale price below zero: the seller pays to offload its output. It occurs when supply exceeds demand and some producers cannot, or have no reason to, shut down.

The price is set each day for the following day on EPEX SPOT, the European power exchange. Three reasons push producers to sell at a loss:

• Technical constraints: a nuclear reactor cannot ramp its output down without limits or costs.
• Support contracts: a guaranteed tariff long encouraged producers to generate, whatever the market price.
• Restart costs: shutting down and restarting can cost more than selling at a loss for a few hours.

The European market's price floor is set at -€500/MWh (Connaissance des Énergies/AFP, 2026). In spring 2026, France came within €2/MWh of it.

How many hours of negative prices has France recorded in 2026?

France recorded 407 hours of negative prices in H1 2026, up from 363 a year earlier (RTE, 2026). Six months were enough to reach almost 80% of the 2025 total of 513 hours (RTE, Electricity Report 2025).

In 2023, France recorded 147 negative hours over the whole year, a record at the time (RTE). From 1 January to 27 May 2026, it had already recorded 306 (Connaissance des Énergies/AFP). Over the same period in 2023, there had been only 24.

• All-time low: -€498.65/MWh on 1 May 2026, a public holiday with low demand (EPEX SPOT). On 26 April, the price had already reached -€478.8/MWh (RTE).
• Duration: a negative price episode lasts about five hours in a row (Connaissance des Énergies/AFP).
• Timing: episodes cluster between 11:00 and 16:00, at the solar peak (EPEX SPOT data, H1 2026).
• Depth: the average negative price is close to -€20/MWh in 2026, versus -€3.2/MWh in 2023 (Connaissance des Énergies/AFP).
• Working days: 38 of the 69 affected days in H1 2026 were working days (RTE).

Negative prices are therefore no longer limited to weekends and May bank holidays. They also occur during business hours.

France is also an outlier in Europe. In H1 2026, negative hours fell in Germany (298), the Netherlands (248) and Belgium (220). Among the countries RTE analysed, only Spain recorded more (628 hours).

Why are negative prices becoming structural in France?

Negative prices are becoming structural because low-carbon midday generation is growing faster than consumption. During solar hours, France produces more than it can consume or export.

• Solar: 30.4 GW installed at the end of 2025, including 5.9 GW connected during the year (RTE, Electricity Report 2025). In summer, the solar peak approaches 20 GW at midday (RTE, 2026).
• Nuclear: 373 TWh generated in 2025 (RTE). In H1 2026, the fleet modulated less: about 10 TWh, versus 15 to 20 TWh a year earlier (RTE).
• Consumption: 451 TWh in 2025, weather-adjusted, up 0.4% year on year (RTE, Electricity Report 2025).
• Exports: a record net export balance of 92.3 TWh in 2025 (RTE). But interconnection capacity is finite, and neighbouring countries also produce solar power at midday.

“Morning and evening price peaks are now higher […] the midday plateau has become a trough.” — RTE, Electricity Report 2025 (our translation)

Public authorities are responding. Up to 7.4 GW of wind and solar capacity under feed-in tariffs can now be curtailed during negative prices (RTE, 2026). Curtailment limits how deep prices fall, but it does not restore the value of a midday kWh.

What do negative prices change for a business?

Negative prices change the value of a kWh depending on when it is produced or consumed. The impact depends on your profile: solar producer, buyer on a market-indexed contract, or buyer on a fixed-price contract.

You produce solar electricity

Surplus exported at midday now earns almost nothing. Since 5 June 2026, the amended S21 Order sets surplus buyback at €0.011/kWh for new installations of 100 kWp or less. Our analysis of the S21 Order by power bracket details this new framework.

At that price, selling surplus covers only a small fraction of the cost of a kWh bought from the grid. On-site self-consumption becomes the main driver of a solar installation's profitability.

An order dated 20 July 2026 lowers the curtailment threshold during negative prices from 10 to 1 MWp. It covers solar and wind plants under public support contracts. It applies from 1 December 2026 above 5 MW, then from 1 March 2027 between 1 and 5 MW. Only producers who follow the stop signal are compensated.

You buy electricity on a market-indexed contract

With a contract indexed to the spot price, negative hours show up on the bill. The energy component collapses at midday, while evenings stay expensive. In H1 2026, the average gap between the day's highest and lowest prices reached €111.3/MWh (RTE).

That is the highest level outside 2022, and more than three times the 2010–2020 average of €33.6/MWh (RTE). This spread fuels spot market arbitrage: store when prices are low, consume when they are high.

You have a fixed-price contract

A fixed-price contract hides negative prices, but not their effects. At renewal, a load profile concentrated on expensive hours gets a higher fixed price. The TURPE (France's public electricity network tariff) for distribution also rose by 3.04% on 1 August 2026 (CRE, 2026).

The TURPE is also moving some off-peak hours to midday. In the low season, from April to October, the preferred off-peak windows are now 02:00–06:00 and 11:00–17:00 (CRE, deliberation no. 2026-33, in French). Enedis, France's main distribution network operator, is rolling out this reform. It covers 11 million customers between November 2025 and the end of 2027, businesses included (Enedis, 2025).

Why shift energy from midday to the evening?

Shifting energy from midday to the evening means storing electricity when it is abundant and cheap, then using it during expensive hours. In H1 2026, 69 days had at least one hour of negative prices (RTE).

A BESS (Battery Energy Storage System, a stationary battery installation) is built for exactly this shift. Its daily cycle runs in four steps:

1. From 11:00 to 16:00: the battery charges from surplus solar power, or from the grid during midday off-peak hours.
2. Late afternoon: it holds its charge while solar output declines.
3. Evening: it powers the site during the consumption and price peak.
4. Night: it tops up during off-peak hours if the site profile justifies it.

This cycle is the principle of peak/off-peak time-of-use shifting. A negative price episode lasts about five hours, enough for a full charge. Battwoo systems operate at C/3: they fully discharge in three hours, enough to cover an evening peak.

Which storage should you choose to handle negative prices?

To handle negative prices, the right storage is a BESS designed for one full cycle per day, over several years. Five criteria matter more than the headline capacity:

• Discharge duration: matched to the evening peak, i.e. three hours for a C/3 system.
• Cycle life: a contractual performance guarantee expressed in cycles, not just in years.
• Health monitoring: Battwoo's BMS (battery management system) measures the SoH (state of health) of every cell.
• Carbon footprint: a second-life battery reuses electric vehicle modules instead of new cells.
• Cost: a lower installed price per kWh than a new system, for equivalent performance over the stationary use window.

How do you assess the value of storage against negative prices?

The value of storage against negative prices is assessed site by site, from the actual load curve. Comparing prices per kWh before sizing means comparing batteries that do not deliver the same service.

1. Analyse the load curve at 10- or 30-minute intervals, over at least twelve months.
2. Overlay solar production, existing or planned, to measure the midday surplus.
3. Review the supply contract: fixed or indexed price, peak/off-peak windows, TURPE tariff option.
4. Simulate several battery sizes against actual hourly prices from 2025 and 2026.
5. Stack the use cases: self-consumption, peak/off-peak shifting, peak shaving, arbitrage and grid flexibility.
6. Size the system, and only then compare offers and prices.

This is the approach behind our sizing study: the right battery size depends on your data, not on a standard ratio. To measure the impact of negative prices on your site, request a study.

Negative prices: key takeaways

• 407 hours of negative prices in H1 2026, about 10% of the time (RTE).
• Episodes of about five hours, concentrated between 11:00 and 16:00.
• An average daily spread of €111.3/MWh between the highest and lowest prices (RTE).
• Solar surplus bought at €0.011/kWh for new installations of 100 kWp or less.
• Off-peak hours moving to 11:00–17:00 in the low season (CRE, 2026).
• A direct way to capture this spread: store at midday, consume in the evening.

FAQ on negative electricity prices

Why doesn't my bill go down when prices are negative?

A fixed-price contract does not pass wholesale prices through hour by hour. With an indexed contract, only the energy component falls, and only during the hours concerned. The TURPE and taxes still apply to every kWh drawn from the grid.

How many hours of negative prices did France have in 2025?

France recorded 513 hours of negative prices in 2025, up from 352 in 2024 (RTE, Electricity Report 2025). Yet the average spot price remained stable, at €61/MWh versus €58/MWh. Negative prices widen the gap between hours without lowering the average.

Will negative prices disappear?

In July 2026, RTE expected frequent episodes until the end of the summer. Curtailment from 1 MWp and the development of flexibility aim to limit how deep prices fall. Their frequency will depend on the pace of solar growth, +5.9 GW in 2025 (RTE), relative to midday consumption.

Do you need solar panels to benefit from negative prices?

No. A BESS can charge from the grid during midday off-peak hours or low-price hours, if the supply contract rewards it. With a solar installation, it also stores surplus that sells for only €0.011/kWh for new installations of 100 kWp or less.

What storage duration should you choose for negative prices?

The battery charges during the roughly five hours of a negative price episode, then covers the evening peak. A C/3 system, like Battwoo's, delivers its full capacity in three hours. The right duration for your site is then set from its load curve.