Negative Electricity Prices in 2026: How Often They Occur and What They Cost PV Investors
In 2025, the exchange price was below zero for 573 hours. How often do negative electricity prices occur, when exactly—and why it is not the exchange figure that counts for revenue calculations, but rather the figures reported by the transmission system operators.
The short answer
Negative electricity prices are a sign of an oversupply of electricity and reflect a profound transformation in the energy system—a phenomenon that has emerged as a result of the energy transition and the expansion of wind and solar energy. They occur when a high and inflexible supply meets low demand, typically on sunny or windy weekends and holidays. For photovoltaic systems, Section 51 of the Renewable Energy Sources Act (EEG) applies: During periods with a negative spot market price, the applicable value is reduced to zero. Which systems are affected and for how long depends on their commissioning date—five different regimes apply in parallel. By no means does every system receive compensation through an extension of the feed-in tariff period under Section 51a of the EEG.
Negative electricity prices are no longer a rare occurrence for operators of photovoltaic systems. In 2025, the price on the electricity exchange was below zero for 573 hours—compared to 301 hours in 2023. These hours of negative prices are not an outlier, but a pattern. During these periods, a large proportion of the systems lose their entitlement to compensation entirely.
This article is intended for operators, investors, and consultants in the photovoltaic sector. It answers three questions using verified data: How often will negative electricity prices actually occur in Germany in 2026, at what exact times of day, and what are the implications for the revenue calculation of a commercial system or solar farm? All figures are sourced from SMARD, the Federal Network Agency, the transmission system operators, and the text of the law, each with the respective effective date.
Two points to note up front. First: Negative electricity prices are increasingly affecting the economic viability of PV systems and presenting operators with new challenges—they are not just a minor issue, but a cost factor in the calculation. Second: There are two different sets of data circulating regarding negative electricity prices, and they do not measure the same thing. If you mix them up, your calculations will be wrong. We cover the legal framework in detail in our article on the Solar Peak Act and Section 51a of the EEG.
How Negative Electricity Prices Arise
The Mechanism of the Electricity Market
On the day-ahead market of the electricity exchange, the price for each delivery period of the following day is determined by supply and demand. Trading takes place via the EPEX SPOT electricity trading platform within the European market network. If there is a large supply of electricity from wind and solar energy while electricity consumption is low, the exchange price on the electricity exchange can drop below zero. The electricity price on the wholesale market then reflects the fact that there is more electricity in the grid than the power system can use at that moment.
The Federal Network Agency describes the mechanism on its market data portal, SMARD, as follows: Negative prices occur when high and inflexible supply meets low demand. This can happen more frequently, for example, on weekends in the summer or on holidays.
Why the offer is inflexible
The key word here is “inflexible.” Conventional power plants have minimum technical load requirements and cannot be shut down on short notice; starting and shutting them down incurs costs that must be recouped within a few hours of operation. For these providers, it makes economic sense to pay for off-take on the wholesale market rather than interrupting generation.
Added to this is the expansion of photovoltaic and wind power plants, which creates power peaks in the grid. The more electricity from renewable sources flows into the grid at the same time, the more frequently negative prices occur on the exchange. And plants that receive subsidies regardless of the market price have historically had no incentive to curtail output—this is precisely where Section 51 of the EEG comes into play. That is the actual purpose of the provision: it is intended to link the control of feed-in to the price signal.
How Often Do Negative Electricity Prices Occur? The Numbers
The number of hours worked at negative wages in Germany has increased significantly in recent years. This trend is clearly evident in the official figures.
| Year | Hours with a negative price | Percentage of the Year |
|---|---|---|
| 2023 | 301 of 8,760 | 3,4 % |
| 2024 | 457 of 8,784 | 5,2 % |
| 2025 | 573 of 8,760 | 6,5 % |
Time series break since October 2025
For 2026, only quarterly figures are available so far, and they are not directly comparable with previous years. Since October 2025, all products on the day-ahead market have been traded in quarter-hourly units, and SMARD has adjusted its database accordingly. The market data portal therefore notes that this change must be taken into account when comparing the data with earlier quarterly and annual reports.
Accordingly, the figures for 2026 are as follows: 172 negative quarter-hours in the first quarter and 1,006 in the second. In the second quarter of 2025, the figure was 1,380.
Extreme Values
The lowest electricity price on the exchange was minus 500.00 euros per megawatt-hour in 2023, minus 135.45 euros in 2024, and minus 250.32 euros in 2025. In the second quarter of 2026, the price once again reached minus 500.00 euros per megawatt-hour—equivalent to minus 50 cents per kilowatt-hour. During the same period, the highest price was 747.10 euros per megawatt-hour, or about 75 cents per kilowatt-hour. The range on a single market thus exceeds 1,200 euros per megawatt-hour, or 1.20 euros per kilowatt-hour—a fluctuation that did not exist in this form before the expansion of renewables.
Two Ways of Counting, Two Numbers — and Why It Matters
This is where this article differs from most accounts. There is not just one figure for negative hours, but rather two official data series with different meanings.
- The exchange data compiled by SMARD and the Federal Network Agency tracks every hour during which the day-ahead price was below zero. It answers the question: How often was electricity priced negatively on the exchange? This is the figure that typically appears in media reports on hourly electricity prices.
- The EEG calculation performed by the four transmission system operators pursuant to Section 51a(4) of the EEG covers the periods during which the applicable value actually fell to zero. It answers the question: How often was the remuneration not paid?
The two sets of rules diverge because the older legal provisions require contiguous periods of a minimum duration. A single negative hour between two positive hours does not trigger any legal consequences under those provisions.
Three legally required rows
Section 51a(4) of the EEG requires transmission system operators to publish three separate sets of data—each by January 31 for the previous year:
- Subsection (a): Quarter-hours, as defined in the current version of Section 51(1)
- Subsection (b): Hours, as amended on February 24, 2025
- Subsection (c): Hours, as of December 31, 2022
On the netztransparenz.de portal, the daily data can even be filtered by seven different eligibility criteria: six hours, four hours, three hours, two hours, one hour, a quarter-hour, and the two-cent threshold for biogas. The six-hour category exists because this rule still applies to older facilities.
Which series applies to your bill
For revenue calculations, the EEG meter reading is the correct basis—specifically, the reading corresponding to the commissioning date of the respective plant. For hourly-based systems, this means that anyone who uses the exchange figure will overestimate the shortfall.
For installations starting on or after February 25, 2025, this is reversed. In that case, every negative quarter-hour counts, while a calendar hour in the hourly tables is only considered negative if the arithmetic mean of its four quarter-hours is below zero. The outage can therefore also exceed the number of exchange hours. For example: On Wednesday, July 29, 2026, the hourly table shows two hours without entitlement, whereas the quarter-hour table shows the period from 12:30 p.m. to 2:45 p.m.—that is, 2.25 hours.
When Negative Electricity Prices Occur
This distribution throughout the day is particularly unfavorable for photovoltaics because it coincides with the peak in generation. The official overview from the transmission system operators illustrates this very clearly for any given summer week.
A Summer Week in the Official Standings
The following example is taken from the hourly table based on a one-hour entitlement and therefore applies to plants commissioned between January 1, 2023, and February 24, 2025, for which the 2026 threshold is two consecutive hours. For older plants subject to the four- or six-hour rule, the shorter time periods do not apply; for plants commissioned on or after February 25, 2025, the quarter-hour table with different time periods applies. During the week of July 25–31, 2026, there was no entitlement to remuneration:
- Saturday, July 25: from 10 a.m. to 5 p.m., or seven consecutive hours
- Sunday, July 26: 11 a.m. to 4 p.m.
- Monday, July 27: from 12 p.m. to 5 p.m.
- Tuesday, July 28: from 12:00 p.m. to 3:00 p.m.
- Wednesday, July 29: from 1:00 p.m. to 3:00 p.m.
- Thursday and Friday: no cancellations
In the quarter-hour schedule, service interruptions sometimes begin at staggered times: on Saturday at 10:15 a.m. instead of 10:00 a.m., and on Sunday starting at 11:30 a.m. instead of 11:00 a.m. Anyone doing precise calculations based on specific systems must refer to the schedule that corresponds to their own basis for entitlement.
The Holiday Effect
The pattern is typical: midday hours, especially on weekends. May 1, 2026, provides another example. SMARD records particularly low prices in Germany and other European countries for the period from 1:15 p.m. to 2:30 p.m. The skies across Europe were nearly cloudless, resulting in correspondingly high feed-in from PV systems across the entire domestic electricity market—and because May 1 is a holiday in most European countries, demand was low throughout Europe.
More solar power does not automatically mean more negative hours
The relationship between expansion and price trends is often portrayed as a simple causal chain. The data supports this only to a limited extent.
| Cutoff Date | Gross Installed PV Capacity | Negative Hours |
|---|---|---|
| End of 2023 | 83,239 MW | 301 |
| End of 2024 | 100,723 MW | 457 |
| End of 2025 | 117,978 MW | 573 |
| June 2026 | 125,372 MW | Quarterly figures only |
These figures refer to gross capacity in the market master data register. The expansion of solar energy is thus the most visible development in the German electricity system in recent years. SMARD reports 103.3 gigawatts for the same quarter because it uses net nominal capacity—here, too, it’s worth paying attention to which figure you’re currently using.
The counterexample from the second quarter of 2026
The coincidence is undeniable. However, this does not prove a causal relationship. In the second quarter of 2026, photovoltaic power generation reached a record quarterly feed-in of 31.8 terawatt-hours, 6.9 percent above the previous record—and yet there were fewer negative quarter-hours than in the same quarter of the previous year: 1,006 compared to 1,380.
SMARD attributes this not to generation, but to the overall higher price level: The average wholesale price, at 95.21 euros per megawatt-hour, was 36.5 percent higher than in the same quarter of the previous year, while wholesale gas prices were about 25 percent higher. In 5,168 out of 8,736 quarter-hours, the price exceeded 100 euros per megawatt-hour, compared to only 2,496 in the same quarter of the previous year.
SMARD consistently cites as the cause the combination of high, inflexible supply—wind and/or solar power—and low demand. It is not installed capacity alone that determines the outcome, but rather the convergence of several factors. Anyone who concludes, based on the expansion of renewables, that negative prices will inevitably follow is oversimplifying the analysis.
What the Elimination of Compensation Means Legally
The current version of Section 51(1) of the EEG is succinct: For periods during which the spot market price is negative, the applicable value is reduced to zero.
As a result, the legal framework is more concise than before. What is noteworthy is what is not included: The current version no longer specifies a minimum duration—neither four hours nor, explicitly, a quarter of an hour. The provision simply refers to time periods. The quarter of an hour comes into play through the calculation method specified in § 51a and the conversion of exchange-traded products.
The Exceptions and Their Expiration Dates
Pursuant to Section 51(2)(1), systems with an installed capacity of less than 100 kilowatts are exempt—meaning a system with exactly 100 kilowatts is not exempt. Furthermore, the exemption applies only to periods prior to the end of the calendar year in which the system is equipped with a smart metering system. It is therefore not a permanent exemption, but rather a transitional rule that expires with the completion of the smart meter rollout.
The current status of the smart meter rollout shows just how much time is still left: Only about 5.5 percent of metering points in Germany are equipped with a smart metering system. For smaller facilities, this effectively pushes back the deadline—making it impossible to plan for. For more details, see the article on the 2026 smart meter mandate.
Item 2 also excludes systems with a capacity of less than 2 kilowatts until the Federal Network Agency has issued its determination pursuant to Section 85(2)(12). The classification of system size is governed by Section 24 of the EEG.
Load Curtailment and Control During Hours with Negative Prices
Just because the payment is waived doesn't mean the plant will shut down. Whether power continues to be fed into the grid during hours with negative prices is a matter of control—and, depending on the marketing channel, that control lies in different hands.
In direct marketing, the direct marketer is in control. The direct marketer has a financial incentive to reduce feed-in to the grid during these periods, because otherwise the electricity would be sold at a negative price. The technical prerequisite for this is remote control capability in accordance with Section 10b of the EEG: The direct marketer must be able to retrieve the actual feed-in data and reduce the output remotely.
This must be distinguished from control by the grid operator. This control comes into play during grid congestion and follows a different logic than the price signal on the exchange. And yet another form of control is governed by Section 14a of the Energy Industry Act (EnWG)—which deals with controllable consumption devices in the low-voltage grid, not with feed-in. In practice, these three levels are regularly confused.
For systems without remote control, the only option is to analyze the data after the fact: They continue to feed power into the grid and receive nothing for those periods.
What Happens to Assessments and Levies
The omission applies to the value to be applied, not to the other components of the statement. Grid fees, surcharges, and levies are governed by their own rules and are not automatically omitted as well. Anyone preparing a revenue statement should list these items separately—otherwise, they will overstate the effect.
Direct Sales and Compensation for Outages
The applicable value affects both the market premium and the feed-in tariff—the regulation does not distinguish between different forms of sale. The difference between direct marketing and the outage compensation is of an economic, not a regulatory, nature. In addition, the compensation for curtailment is subject to the reporting requirement under Section 51(3): Anyone who fails to report the amount of electricity fed into the grid during periods of negative generation to the grid operator loses five percent of their entitlement for that month for each affected calendar day. The article on current direct marketing prices shows how marketing prices are developing.
Five Regimes Side by Side: Which One Applies to Your Investment?
A common mistake in consulting practice is the assumption that there is a single, uniform rule. In fact, five different regimes apply simultaneously. The decisive factor is the date of commissioning or the bid deadline:
| Commissioning or Award of Contract | Applicable Rule | Exception under |
|---|---|---|
| before January 1, 2016 | Section 51 of the EEG does not apply | — |
| January 1, 2016, through December 31, 2020 | at least six consecutive negative hours | — |
| January 1, 2021, through December 31, 2022 | at least four consecutive hours | 500 kW |
| January 1, 2023, through February 24, 2025 | Schedule: Four hours in 2023, three hours in 2024 and 2025, two hours in 2026, and one hour starting in 2027 | 400 kW |
| Starting February 25, 2025 | any time period with a negative price | 100 kW by the year smart meters are rolled out, 2 kW by the time the BNetzA sets the standard |
The fact that these gradations actually exist can be seen on the transmission system operators’ portal: The daily data there can be filtered according to precisely these eligibility criteria, ranging from the six-hour rule to the quarter-hour rule. Existing plants retain their old hourly thresholds under Section 100(46) of the EEG.
Three Common Misconceptions
First: The statement that the four-hour rule applied until February 2025 is not accurate. It applies to systems installed in 2021 and 2022—prior to that, the rule was six hours, and for systems installed in 2023 and later, the three-hour rule applied in 2024 and 2025.
Second: The thresholds for the middle group are based on the calendar year, not the year of commissioning.
Third —and this is the most important practical point of this article: For this group, the threshold will drop to two hours in 2026 and to one hour starting in 2027, automatically and without the need for any new legislation. This phased reduction has been enshrined in law since the Electricity Price Cap Act of December 2022. For new installations starting February 25, 2025, the old four-hour rule will be completely eliminated anyway: If the exchange price is negative, they will immediately cease to receive any feed-in tariff.
Anyone with an investment from the middle group in their portfolio should calculate the impact for 2027 before they feel it.
What Investors Can Expect from This
No official source provides a reliable figure for the loss of revenue from a specific facility. Anyone who cites a figure calculates it themselves—and should disclose the input data.
Available metrics for the calculation
- The annual market value for solar power in 2025 under Annex 1 of the EEG: 4.508 cents per kilowatt-hour. This should not be confused with the market value for solar power under Section 33 of the EEG 2012, which stands at 6.170 cents per kilowatt-hour for the same year—different legal basis, different calculation. The market value factors for photovoltaics decline even further during periods of negative prices.
- The periods during which there is no entitlement to compensation, as shown in the transmission system operators’ overview—in the row that corresponds to your own basis for entitlement. The portal provides daily data and a CSV export for your own analysis; you must calculate the annual total yourself.
- The full-load quarter-hour table in Section 51a(2) of the EEG, which the legislature uses to model how solar generation is distributed throughout the year: from 73 in December, through 87 in January, to 508 in June.
The Methodological Pitfall
The percentage of downtime relative to total annual hours is not the same as the percentage of lost revenue. The outages occur during lunchtime—precisely when the plant is generating its highest output. Anyone who calculates the loss of revenue proportionally to the number of hours will underestimate it. Only the individual load profile provides a reliable figure.
The compensation under Section 51a is by no means available everywhere
This is the biggest source of error in consulting practice. The often-heard claim that the compensation period is extended accordingly does not hold true in such general terms.
For systems installed on or after February 25, 2025, Section 51a(1) extends the remuneration period by the number of missed quarter-hours, rounded up to the next full calendar day. For solar systems, this number is multiplied by a factor of 0.5 in accordance with paragraph 2 and reduced using the full-load quarter-hour table.
This does not apply to all older systems. Section 100(46), second sentence, of the EEG excludes the application of Section 51a(2) to solar power systems that were commissioned before February 25, 2025. Furthermore, Section 51a(1) in the older version applicable to these systems grants the extension only to systems whose applicable value is determined through tenders—and calculates it in hours, not in quarter-hours.
What Might Change with the EEG 2027
On July 29, 2026, the Federal Cabinet approved the draft amendment to the EEG, which is intended to rename the law the EEG 2027. The draft completely replaces Section 51. The new heading reads: “Reduction of the Right to Payment and the Obligation to Pay in the Event of Negative Prices.” Section 51a is also being amended; the heading will henceforth refer to the “extension of the payment period.” The amendment is scheduled to take effect on January 1, 2027.
Important for context: As of the editorial deadline for this article on August 14, 2026, the draft has been forwarded to the Bundesrat, but the first reading has not yet taken place—the next plenary session is scheduled for September 25, 2026. The government draft has not yet been introduced in the Bundestag; a search in the Documentation and Information System reveals no record of it for the 21st legislative period. This should be distinguished from a parliamentary group draft of the same name, which has already been referred to committee. Statements regarding its applicability starting in 2027 are therefore not yet confirmed. We will update this section as soon as the legislative process resumes. The current feed-in rates are listed in the 2026 EEG Remuneration Guide.
Options for Operators and Investors
Based on the available data, four practical approaches emerge, though we do not intend to make any promises regarding returns here:
- Increase self-consumption. Every kilowatt-hour consumed on-site is not subject to § 51 at all. For businesses with a load profile during the midday hours, this is the most direct way to achieve this.
- Shift loads. Flexible commercial consumers can strategically time their electricity usage to coincide with periods when prices are positive. What is achieved through dynamic electricity rates for households is a matter of load management in the commercial sector.
- Examine storage. Negative prices create incentives for investment in battery storage because they shift generation from hours with negative prices to times when prices are positive. This makes investments in flexibility and storage solutions even more urgent. We discuss how to build a revenue model based on this in our article on arbitrage with battery storage; we cover the combination with dynamic rates in our article on battery storage and dynamic rates.
- Understand your specific system and apply the correct calculation method. Which of the five versions applies to a given installation determines the order of magnitude. For revenue calculations, use the EEG calculation method of the transmission system operators, not the exchange calculation method. For existing portfolios, it’s worth checking on a per-installation basis.
Classify your own portfolio by asset class
Which of the five regimes applies to a system, and whether the compensation under Section 51a applies at all, is determined by the date of commissioning and the form of marketing. Logic Energy designs, builds, and operates turnkey PV systems and supports investors from the planning stage through ongoing operations. The contractual partner for direct investments is mediplan Helm e.K., a partnership with personal liability of the owners.
Frequently Asked Questions About Negative Electricity Prices
How many hours of negative electricity prices have there been recently?
On the day-ahead market, the exchange price was below zero for 301 hours in 2023, 457 hours in 2024, and 573 hours in 2025—corresponding to 3.4%, 5.2%, and 6.5% of each respective year. For 2026, only quarterly figures are available so far: 172 negative quarter-hours in the first quarter and 1,006 in the second. The source is the Federal Network Agency and SMARD, respectively.
Why are there two different figures for negative hours?
Because they measure different things. SMARD and the Federal Network Agency count every hour with a negative exchange price. Transmission system operators, in accordance with Section 51a(4) of the Renewable Energy Sources Act (EEG), count the periods during which the applicable value actually fell to zero—where the older legal provisions require a minimum duration. The second set of rules applies to revenue calculations.
At what point does compensation cease when prices are negative?
That depends on the commissioning date. Systems commissioned before January 1, 2016, are not affected at all. From 2016 to 2020, the rule applies for six consecutive hours; in 2021 and 2022, it applies for four hours, with an exception for systems under 500 kilowatts. For systems commissioned between 2023 and February 24, 2025, a tiered system applies; starting February 25, 2025, any period with a negative price counts.
Will the regulation automatically become stricter in 2027?
For facilities commissioned between January 1, 2023, and February 24, 2025, yes. Their threshold will drop to two consecutive hours in 2026 and to one hour starting in 2027. This graduated scale has been in law since the Electricity Price Cap Act of December 2022; no new legislation is required.
Is the outage always compensated for under Section 51a of the EEG?
No. For systems commissioned on or after February 25, 2025, the remuneration period is extended by the number of quarter-hours lost, multiplied by a factor of 0.5 for solar systems. For older systems, Section 100(46), second sentence, of the EEG excludes the application of Section 51a(2), and the older version of Section 51a(1) grants the extension only to systems whose applicable value was determined through tenders.
Does the plant have to be shut down during hours when the price is negative?
No, the loss of remuneration does not constitute an obligation to shut down. In direct marketing, the direct marketer has an economic incentive to reduce feed-in and uses the remote control provisions under Section 10b of the Renewable Energy Sources Act (EEG) for this purpose. This must be distinguished from control by the grid operator during grid congestion and the provisions of Section 14a of the Energy Industry Act (EnWG) regarding controllable consumption facilities.
Are grid fees and surcharges also waived during these periods?
No. The elimination applies exclusively to the value to be applied. Grid fees, surcharges, and levies are governed by their own rules and are not automatically eliminated as well. In a revenue statement, these items must be reported separately; otherwise, the calculated effect will be too large.
Conclusion
Negative electricity prices have risen from 301 hours in 2023 to 573 in 2025. According to SMARD, they typically occur on sunny and windy weekends and holidays; no official data is available on their distribution by time of day. The decisive factor for remuneration is not the exchange figure, but the transmission system operator’s count—specifically, the series that corresponds to the commissioning date of the respective facility.
Two points are regularly overlooked in practice. First, the graduated scale for facilities commissioned between 2023 and February 2025: Their threshold drops to two hours in 2026 and to one hour in 2027, automatically and without a new resolution. Second, the compensation under Section 51a, which does not apply at all to facilities commissioned before February 25, 2025, with a statutory applicable value.
Anyone who has such systems in their portfolio should calculate both now.
References
- Federal Network Agency, SMARD — Data on the Electricity Market for 2024 and 2025, Press Releases dated January 3, 2025, and January 5, 2026
- SMARD — Quarterly Reports for Q1 2026 (May 18, 2026) and Q2 2026 (August 3, 2026), Feature Article “Negative Wholesale Prices”
- Transmission System Operator, netztransparenz.de — Negative spot market price, summary tables pursuant to Section 51a(4) of the EEG, as of August 13, 2026; Market value overview
- EEG 2023, as amended on December 18, 2025 — Sections 10b, 21, 21b, 24, 51, 51a, 100
- Electricity Price Cap Act of December 20, 2022, Federal Law Gazette 2022 I No. 54
- Act Amending Energy Industry Law to Prevent Temporary Surpluses in Electricity Generation, dated February 21, 2025, published on February 24, 2025, in the Federal Law Gazette (BGBl.) 2025 I No. 51; the amendment to Section 51 has been in effect since February 25, 2025
- EEG 2021, Section 100(2)(13) (Six-Hour Rule for Plants 2016–2020), Federal Law Gazette 2020 I, p. 3138
- Federal Council, Plenary Session Schedule; German Bundestag, Documentation and Information System
- Federal Government and BMWE — Cabinet Decision on the EEG Amendment of July 29, 2026, Draft Bill
- Federal Network Agency — Renewable Energy Statistics (MaStR), data as of July 13, 2026
