At a glance
- For new renewable plants, the subsidy ends from the first quarter hour of negative electricity prices
- Mainly affected are solar and wind plants in direct selling with a market premium
- Some small plants are exempt
- The lost time is added to the end of the subsidy period, for solar plants only by half
- Accurate generation forecasts thus become an economic factor
What has changed
Since February 25, 2025, a stricter version of Section 51 of the German Renewable Energy Sources Act (EEG) has applied to new renewable energy plants. Previously, the subsidy only ended when spot market prices had been negative for several consecutive hours. This grace period, or hourly rule, has been significantly shortened: when spot market prices are negative, the payment entitlement now drops to zero for the affected period, quarter hour by quarter hour.
Who is affected and who is not
Mainly affected are plants in direct selling with a market premium. For these plants, the subsidy is lost entirely for each quarter hour with negative electricity prices. This is particularly relevant for solar and wind plants: on sunny and windy days in particular, high feed-in and negative exchange prices often coincide.
Exemptions include:
- Plants with less than 100 kilowatts of installed capacity, as long as they do not yet have a smart metering system
- Plants under 2 kilowatts, until the Federal Network Agency has issued a corresponding ruling
Compensation under Section 51a EEG
As compensation, Section 51a EEG extends the subsidy period by the lost quarter hours. For solar plants, only half of the lost time is credited. Economically, it remains a loss: an extended subsidy many years from now does not replace revenue today.
What this means for planning
For balance responsible parties, renewable aggregators and operators of solar and wind plants, the pressure on planning increases. What matters is knowing in good time how much your own plants will feed in during the critical hours. Only then can sales, schedules, curtailment or storage use be aligned with these risk windows.
This is exactly where accurate generation forecasts become an economic factor. The more accurate the forecast, the lower the risk of feeding in unplanned during periods of negative prices.
How metalogic supports you
For metalogic, this is a topic we factor into our generation and consumption forecasts for grid operators, balance responsible parties, renewable aggregators and utilities. mP Xnergy creates plant-level forecasts for wind and solar, continuously updates them with new weather data and uses mP Scenario to show the range within which feed-in may fall.
Find out more on our pages for generators & renewables and renewable aggregators. Or contact us directly.
