Negative power prices 2026: what they take from your solar system
In 2025, the German wholesale price was below zero for 573 hours, and 24 % of German solar output fell into those hours. A new 10 kWp system with a smart meter loses about €166 of feed-in payment a year as a result.
Checked by Radif Partners · Editorial policy · How we calculate
What negative prices mean for your feed-in
Payment lost per year
€166
| Hours with negative prices 2025 | 573 |
| Share of solar output in those hours | 24 % |
| Rule for your system | no payment (section 51 EEG) |
Negative power prices occur when more electricity is offered on the exchange than is demanded and generators pay to get rid of it. The Federal Network Agency’s market data platform SMARD shows the trend: in 2024 there were 457 hours with a negative day-ahead price, in 2025 already 573. Most fall on sunny middays between April and August; June 2025 alone had 141 hours. For solar, what matters most is how much solar power is produced in those hours: 24 % in 2025. Under section 51 EEG, new systems earn nothing for those quarter-hours once a smart meter is installed, small systems from the following calendar year. A 10 kWp system on the national average loses €166 a year, or €135 with an 8 kWh battery. Without a smart meter the payment stays whole, but the 60 % cap applies. Section 51a adds half of the lost time to the end of support.
Why power sometimes costs less than nothing
On the exchange’s day-ahead market, a price is set for every hour of the next day, and since 2025 for every quarter-hour. When supply exceeds demand the price falls, and if power stations cannot throttle quickly enough or systems are paid a fixed rate, it slips below zero. Sellers then pay for someone to take their power. For owners of small solar systems this long had no consequences, because their rate was fixed. Since 25 February 2025, new systems are treated differently: section 51 EEG sets the reference value to zero for those periods.
The years compared
| Year | Hours with negative price | Share of solar output | Market value of solar |
|---|---|---|---|
| 2024 | 457 | 18.4 % | 4.62 ct/kWh |
| 2025 | 573 | 24.1 % | 4.61 ct/kWh |
| 2026 (to 15 October 2026) | 460 | 21.7 % | 5.94 ct/kWh |
The number of hours keeps rising because several gigawatts of PV are added every year, all producing at the same time around noon. For system owners, the share of solar output in negative hours is the more important figure: it tells you which part of annual exports would go unpaid. The output-weighted market value also shows how little a kilowatt-hour of solar power earns on the market on average, compared with the fixed rate of 7.70 ct/kWh for a new 10 kWp system.
Month by month
| Month | Hours 2024 | Hours 2025 | Hours 2026 | Solar share 2025 |
|---|---|---|---|---|
| January | 16 | 14 | 2 | 3.5 % |
| February | 4 | 0 | 7 | 0.0 % |
| March | 12 | 30 | 33 | 13.4 % |
| April | 50 | 75 | 123 | 32.6 % |
| May | 78 | 129 | 77 | 43.7 % |
| June | 64 | 141 | 49 | 46.9 % |
| July | 81 | 12 | 79 | 5.2 % |
| August | 68 | 64 | 54 | 22.2 % |
| September | 40 | 60 | 36 | 24.5 % |
| October | 25 | 48 | 0 | 8.7 % |
| November | 11 | 0 | – | 0.0 % |
| December | 8 | 0 | – | 0.0 % |
The pattern is clear. In winter, negative prices occur almost only on windy nights, when there is hardly any solar output; the solar share then stays at zero. From April to August, by contrast, they fall at midday, exactly when a rooftop system exports most. The 141-hour month of June 2025 took 46.9 % of the monthly payment from a system with a smart meter. Individual months also swing strongly between years: weather, holidays and wind move the figures considerably.
What it means for your payment
Whether your system is affected depends on its commissioning date and meter. Systems running before 25 February 2025 follow the old rule. New systems below 100 kW keep earning on every kilowatt-hour without a smart metering system. With a smart meter, the zero rate applies from 1 January of the year after installation.
| System (smart meter) | Export | Payment without zero rate | of which lost |
|---|---|---|---|
| 5 kWp | 3,906 kWh | €301 | €73 |
| 10 kWp | 8,936 kWh | €688 | €166 |
| 10 kWp with 8 kWh battery | 7,273 kWh | €560 | €135 |
| 10 kWp east-west | 6,937 kWh | €534 | €129 |
| 15 kWp | 14,098 kWh | €1,037 | €250 |
The calculation assumes your system is affected in the same proportion as German solar output as a whole. A battery reduces the loss only a little, because on sunny days it is usually full by midday; only a control that charges it deliberately during negative hours turns this into an advantage. The loss is partly made up by section 51a EEG: half of the lost quarter-hours is added as a time allowance after the 20 years. Details on this and on the switch between cap and zero rate are under solar peak law.
Who supplies the figures
Whether a quarter-hour was negative is not left to your grid operator’s judgement. Each year, by mid-January, the power exchanges report the number of zero-rated quarter-hours and hours to the transmission system operators, who publish them by the end of January on a joint website (section 51a(3) and (4) EEG). This also sets the time allowance for the later extension. In your annual statement, the deduction shows up as a lower payment for the affected periods; you can check it against your smart meter’s load profile.
Dynamic tariffs as the flip side
For households with a smart meter, negative prices also have an upside. Dynamic electricity tariffs pass on the exchange price hourly or per quarter-hour; network charges, levies and VAT are added, but the energy price drops sharply in those hours. If you control an electric car, a heat pump with a buffer tank or an immersion heater flexibly, you can draw power exactly then. With your own solar system the benefit is smaller, since your own power is there at midday anyway; it shows mainly on dull, windy days. Which meter you need is under meters. Under the government draft of the EEG 2027, the zero rate at negative prices would remain for new systems (feed-in tariff 2027).