Energy market · Negative price protection
Negative power prices: what they cost your plant
On sunny days with low demand, the wholesale power price falls below zero more and more often. If your PV system keeps running in direct marketing, it feeds in without being paid for it – and, depending on the contract, you may even pay on top.
What happens during negative hours
For plants commissioned since 25 February 2025, the reference value used to calculate the market premium falls to zero in hours with a negative spot price (Section 51 of the German Renewable Energy Sources Act, EEG): the market premium lapses. There is no obligation to switch the plant off; it keeps feeding in unless someone curtails it.
The direct marketer does not curtail on its own initiative. Many standard contracts pass the spot price through, even when it is negative. What this means for you is set out in your contract.
Older plants commissioned before 25 February 2025 are not automatically covered by this rule. Depending on the year of commissioning, earlier rules apply to them; a voluntary switch to the new rule is possible (Section 100(47) EEG). Whether and how your plant is affected is the first thing we clarify.
Negative hours are no longer the exception: according to analyses for 2025 there were several hundred of them in Germany, and the trend is rising.
The negative price check for your plant
Using actual spot prices from the last twelve months, we calculate what negative prices have cost your plant and show you how to stop it. At a fixed price, which you receive in writing after the initial call.
01
Data
Plant data, commissioning date, direct marketing contract and, if available, the feed-in values for the last twelve months.
02
Analysis
We set the feed-in against the hourly spot prices and calculate what the plant has lost during negative hours.
03
Result
The figure for your plant – not a flat estimate – and which of the three ways pays off for you.
Three ways to limit the losses
Review the direct marketing contract
Who bears negative prices, is there curtailment, how is it settled? If the contract does not fit, you can switch direct marketer at the start of a month, as far as your contract allows.
Curtail during negative hours
Feed-in can be reduced during these hours via the inverters or a power plant controller, coordinated with the direct marketer and the network operator.
Consume or store on site
Where there is on-site demand, the business or a battery absorbs the power during these hours. For feed-in-only plants without consumption, a battery rarely pays off for this purpose.
Automatic control
We are building a control system that evaluates spot prices and forecasts and curtails plants selectively during negative hours. It is currently running at pilot plants in observation mode, i.e. without actual switching operations, and logs when it would have switched. Customers can see this in the portal. We will only start regular operation once it has been agreed with the direct marketer and the network operator.
Related: Storage + PV · O&M and asset management
How much do negative prices cost your plant? We will calculate it with your data.