Feed-in tariff calculator
Calculates feed-in revenue with the proportional EEG tiering many calculators get wrong: at 15 kWp the first 10 kWp earn 7.70 ct and only the rest 6.66 ct — a blended 7.35 ct instead of 9.4 % too little. The exported amount comes from your location and a household load profile rather than a guess, and the 60 % cap is counted hour by hour: 1.7 % loss on a Berlin south roof instead of the usual 6 % flat assumption. Rates come from the versioned dataset (official as of 08/2026).
The formulas behind the calculator
Every number above can be recomputed: the full calculation path, all assumptions and the data source with retrieval date — plus cross-validation against independent references. Disclosed, not claimed.
An estimate based on the stated assumptions. The final design must be checked by a qualified professional against the rules that apply where you are.
Data as of: 2026-08-06
| Step | Formula | Value | Provenance |
|---|---|---|---|
| Blended rate | Σ(kWp_j * rate_j) / Σ kWp_j | 7.3533 ct/kWh | measured |
| Exported energy | Σ_h max(0, PV_h - Haushalt_h) | 13,653 kWh/a | measured |
| Annual revenue | E_einsp * f_Deckel * (1 - f_Negativpreis) * Satz / 100 | 986.73 Waehrung/a | exact |
- Formula
Blended rate = Σ (kWp_segment · rate_segment) / kWp_total · Export = Σ_h max(0, PV_h − household_h) · Clipping loss = Σ_h max(0, export_h − 0.6 · kWp) · Revenue = E_export · blended rate · f_cap · (1 − negative share)- Valid for
- Bundesnetzagentur rates for commissioning 2026-08-01 to 2027-01-31 (partial feed-in; half-yearly 1 % degression applied), proportional tiering under § 48 EEG. Exported energy and clipping loss come from the site hourly year (PVGIS-SARAH3 TMY) and the household load profile — the same chain as the self-consumption calculator. Reference case: 15 kWp in Berlin, 4,000 kWh consumption → 13,653 kWh exported, blended rate 7.35 ct, clipping loss 1.7 % (234 kWh over 306 hours), flat-rate error 9.4 %. Data age is monitored — stale rates raise a warning.
- Not covered
- Full feed-in rates, direct marketing (mandatory above 100 kWp), the Solarpaket I bonus (not in force under state-aid rules), extension of the support period as negative-price compensation (announced, not evaluated here), discounting (calculators 41/42). The negative-price share remains a visible assumption with a range, not an hourly price simulation — that follows once a freely licensed negative-price series is committed. Clipping is computed without a battery: one charging at midday reduces the loss further (calculators 43/44).
- Data sources
- Bundesnetzagentur SMARD electricity price analysis, StromAuskunft price index (as of 2026-08-06) and EEG remuneration rates per § 48 EEG 2023 · Q3/2026 (EEG-Sätze H2/2026) · retrieved 2026-08-06
Frequently asked questions
How high is the German feed-in tariff from August 2026?
For commissioning between 1 Aug 2026 and 31 Jan 2027 (partial feed-in): 7.70 ct/kWh up to 10 kWp, 6.66 ct up to 40 kWp, 5.44 ct up to 100 kWp — official BNetzA rates after the semi-annual 1% degression. The calculator reads the rates from a versioned dataset; if they go stale, it warns.
Why don't I simply get the 15 kWp rate at 15 kWp?
Because the EEG tiers apply PROPORTIONALLY: the first 10 kWp of your system earn 7.70 ct, only the remaining 5 kWp earn 6.66 ct — blended rate 7.35 ct. Many calculators wrongly apply the whole-system rate to the entire volume and under-count by 9.4%. The tiered bar shows the decomposition.
What does the negative-price rule do to my revenue?
For systems from 2 kWp commissioned since 25 Feb 2025, remuneration lapses in quarter-hours with negative exchange prices. 2025 saw about 575 such hours, rising — and they cluster around midday, which is why south-facing roofs are hit harder than east-west. As compensation the support period is extended; the calculator deliberately does not value that.
How does the 60% feed-in cap affect revenue?
Without a smart meter and control box the system may export only 60% of its power. The energy loss depends on orientation: HTW measures up to 9% for south, about 1% for east-west — the midday peaks get clipped. In the calculator you set the remaining revenue share as a visible assumption; balcony systems are exempt from the cap.
Is feeding in even worth it any more?
Barely: the LCOE calculator shows the reference case's cost of energy (7.74 ct) now sits ABOVE the tariff (7.70 ct). Feed-in revenue is side income, not a source of return — the return arises in self-consumption. That is why this calculator takes the exported volume directly from the self-consumption calculator.
Does the full-feed-in rate apply here too?
No — this calculator computes partial feed-in (system with self-consumption). Full feed-in earns higher rates (12.22 ct up to 10 kWp as of 08/2026) but must be declared before the calendar year; that variant is not yet modelled in the dataset and is stated as a limit in the methodology.
Where does the exported energy figure come from?
From your location, not from a guess. The calculator simulates the hourly year of your system from TMY data and subtracts a household load profile hour by hour. What remains is exported. For 15 kWp in Berlin with 4,000 kWh consumption that is 13,653 kWh per year — 89 % of the 15,384 kWh generated. If you have a measured figure from your annual statement, the “enter exported energy manually” switch lets you override it.
What does the German 60 % cap actually cost?
Far less than the common rule of thumb of 5 to 10 %. The cap limits POWER, not annual energy: only what exceeds 0.6 × kWp in a given hour is lost. In the Berlin example with 15 kWp facing south that is 234 kWh per year — 1.7 %, spread over 306 hours. The calculator counts those hours individually instead of applying a flat factor.
Why does an east-facing roof lose almost nothing to the cap?
Because the cap only shaves the peak, and an east roof barely has one. The same system loses 33 kWh facing east instead of 234 kWh — 0.3 % instead of 1.7 %, and in 76 instead of 306 hours. That is why a flat factor is wrong here: the effect depends on orientation, pitch and self-consumption, not on system size.
Does self-consumption reduce the clipping loss?
Yes, and it is often overlooked. The limit applies at the grid connection point, so it only concerns what actually leaves the house. Every kilowatt-hour used at midday — heat pump, car, battery — lowers the exported power and therefore exactly the peak that would be clipped. The calculator subtracts the household profile BEFORE applying the cap.
Is a smart meter worth it just to avoid the cap?
Rarely for the clipped energy alone. 234 kWh per year at 7.35 ct is about €17 — that will not pay for metering point operation. The control box pays off through other routes: dynamic tariffs, direct marketing, grid-serving control. Treat the clipping loss as a minor item, not the main argument.