feat: add Akkudoktor feed-in provider (#1187)

The `FeedInTariffAkkudoktor` provider uses raw day-ahead market prices from
`https://api.akkudoktor.net/prices` as `feed_in_tariff_wh`. It does not add electricity import
charges or VAT. Published prices are extended to the configured prediction horizon with the same
seasonal ETS or median fallback used by the Akkudoktor electricity-price provider.

The Akkudoktor endpoint currently forwards hourly market prices from aWATTar. With a 15-minute
optimization interval, EOS holds each hourly price constant for its four quarter-hour slots. This
keeps the slot grid consistent but does not create genuine quarter-hour market prices.

Signed-off-by: Andreas Schmitz <akkudoktor.net>
Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

src/akkudoktoreos/prediction/feedintariff.py

@@ -20,9 +20,10 @@ def feedintariff_provider_ids() -> list[str]:
         # Prediction may not be initialized
         # Return at least provider used in example
         return [
+            "FeedInTariffAkkudoktor",
             "FeedInTariffEnergyCharts",
             "FeedInTariffFixed",
-            "FeedInTarifImport",
+            "FeedInTariffImport",
         ]
 
     return [

src/akkudoktoreos/prediction/feedintariffakkudoktor.py

@@ -0,0 +1,161 @@
+"""Provide feed-in tariff data from Akkudoktor market prices."""
+
+import time
+from datetime import datetime
+from typing import Optional
+
+import numpy as np
+import pandas as pd
+import requests
+from loguru import logger
+
+from akkudoktoreos.config.configabc import SettingsBaseModel
+from akkudoktoreos.core.cache import cache_in_file
+from akkudoktoreos.prediction.elecpriceakkudoktor import (
+    AkkudoktorElecPrice,
+    ElecPriceAkkudoktor,
+)
+from akkudoktoreos.prediction.feedintariffabc import FeedInTariffProvider
+from akkudoktoreos.utils.datetimeutil import to_datetime, to_duration
+
+
+class FeedInTariffAkkudoktorCommonSettings(SettingsBaseModel):
+    """Settings for the Akkudoktor feed-in tariff provider.
+
+    The public Akkudoktor price endpoint only needs the timezone already
+    configured in ``general.timezone``, so no provider-specific values are
+    currently required.
+    """
+
+
+class FeedInTariffAkkudoktor(FeedInTariffProvider):
+    """Use raw Akkudoktor day-ahead market prices as feed-in tariff data.
+
+    The upstream aWATTar endpoint currently supplies hourly values. EOS stores
+    those source values unchanged; consumers requesting a shorter interval can
+    forward-fill them onto the optimization grid.
+
+    Electricity export charges and VAT are intentionally not added. Prices
+    returned in EUR/MWh are converted to EUR/Wh and stored under
+    ``feed_in_tariff_wh``.
+    """
+
+    highest_orig_datetime: Optional[datetime] = None
+
+    def historic_hours_min(self) -> int:
+        """Keep enough history for weekly seasonal price extrapolation."""
+        return 24 * 35
+
+    @classmethod
+    def provider_id(cls) -> str:
+        """Return the unique provider identifier."""
+        return "FeedInTariffAkkudoktor"
+
+    @cache_in_file(with_ttl="1 hour")
+    def _request_forecast(self) -> AkkudoktorElecPrice:
+        """Fetch market prices from the public Akkudoktor API."""
+        if not self.ems_start_datetime:
+            raise ValueError(f"Start DateTime not set: {self.ems_start_datetime}")
+
+        start_date = to_datetime(
+            self.ems_start_datetime - to_duration("35 days"), as_string="YYYY-MM-DD"
+        )
+        end_date = to_datetime(self.end_datetime, as_string="YYYY-MM-DD")
+        timezone = self.config.general.timezone
+        url = f"https://api.akkudoktor.net/prices?start={start_date}&end={end_date}&tz={timezone}"
+
+        max_attempts = 3
+        last_exc: Optional[Exception] = None
+        for attempt in range(1, max_attempts + 1):
+            try:
+                response = requests.get(url, timeout=(5, 20))
+                logger.debug("Response from {}: {}", url, response)
+                response.raise_for_status()
+                data = ElecPriceAkkudoktor._validate_data(response.content)
+                self.update_datetime = to_datetime(in_timezone=timezone)
+                return data
+            except (requests.exceptions.Timeout, requests.exceptions.ConnectionError) as exc:
+                last_exc = exc
+                logger.warning(
+                    "Akkudoktor feed-in tariff request attempt {}/{} failed: {}",
+                    attempt,
+                    max_attempts,
+                    exc,
+                )
+                if attempt < max_attempts:
+                    time.sleep(2 * attempt)
+
+        raise last_exc  # type: ignore[misc]
+
+    def _parse_data(self, data: AkkudoktorElecPrice) -> pd.Series:
+        """Convert raw EUR/MWh values to a timezone-aware EUR/Wh series."""
+        series = pd.Series(dtype=float)
+        for value in data.values:
+            timestamp = to_datetime(value.start, in_timezone=self.config.general.timezone)
+            series.at[timestamp] = value.marketprice / 1_000_000
+        return series
+
+    def _predict_prices(self, history: np.ndarray, hours: int) -> np.ndarray:
+        """Extend published prices to the configured prediction horizon."""
+        predictor = ElecPriceAkkudoktor()
+        if len(history) > 800:
+            return predictor._predict_ets(history, seasonal_periods=168, hours=hours)
+        if len(history) > 168:
+            return predictor._predict_ets(history, seasonal_periods=24, hours=hours)
+        if len(history) > 0:
+            logger.warning(
+                "Using median fallback for Akkudoktor feed-in tariff with only {} values.",
+                len(history),
+            )
+            return predictor._predict_median(history, hours=hours)
+        raise ValueError("No Akkudoktor feed-in tariff data available")
+
+    async def _update_data(self, force_update: Optional[bool] = False) -> None:
+        """Update raw prices and extrapolate any missing horizon values."""
+        if not self.ems_start_datetime:
+            raise ValueError(f"Start DateTime not set: {self.ems_start_datetime}")
+
+        try:
+            data = self._request_forecast(force_update=force_update)  # type: ignore[call-arg]
+            series = self._parse_data(data)
+            if series.empty:
+                raise ValueError("No Akkudoktor feed-in tariff data available")
+            self.highest_orig_datetime = to_datetime(
+                series.index.max(), in_timezone=self.config.general.timezone
+            )
+            await self.key_from_series("feed_in_tariff_wh", series)
+        except Exception as exc:
+            if self.highest_orig_datetime is None:
+                raise
+            logger.warning(
+                "Akkudoktor feed-in tariff update failed ({}); retaining existing data.",
+                exc,
+            )
+
+        if self.highest_orig_datetime is None:
+            raise ValueError("Highest original datetime not available")
+
+        history = np.asarray(
+            await self.key_to_array(
+                key="feed_in_tariff_wh",
+                end_datetime=self.highest_orig_datetime,
+                fill_method="linear",
+            ),
+            dtype=float,
+        )
+        covered_hours = (
+            int((self.highest_orig_datetime - self.ems_start_datetime).total_seconds() // 3600) + 1
+        )
+        needed_hours = self.config.prediction.hours - max(covered_hours, 0)
+        if needed_hours <= 0:
+            return
+
+        prediction = self._predict_prices(history, needed_hours)
+        prediction_series = pd.Series(
+            data=prediction,
+            index=[
+                self.highest_orig_datetime + to_duration(f"{i + 1} hours")
+                for i in range(len(prediction))
+            ],
+        )
+        await self.key_from_series("feed_in_tariff_wh", prediction_series)

src/akkudoktoreos/prediction/prediction.py

@@ -36,6 +36,7 @@ from akkudoktoreos.prediction.elecpriceenergycharts import ElecPriceEnergyCharts
 from akkudoktoreos.prediction.elecpricefixed import ElecPriceFixed
 from akkudoktoreos.prediction.elecpriceimport import ElecPriceImport
 from akkudoktoreos.prediction.elecpricetibber import ElecPriceTibber
+from akkudoktoreos.prediction.feedintariffakkudoktor import FeedInTariffAkkudoktor
 from akkudoktoreos.prediction.feedintariffenergycharts import FeedInTariffEnergyCharts
 from akkudoktoreos.prediction.feedintarifffixed import FeedInTariffFixed
 from akkudoktoreos.prediction.feedintariffimport import FeedInTariffImport
@@ -82,6 +83,7 @@ elecprice_energy_charts = ElecPriceEnergyCharts()
 elecprice_fixed = ElecPriceFixed()
 elecprice_import = ElecPriceImport()
 elecprice_tibber = ElecPriceTibber()
+feedintariff_akkudoktor = FeedInTariffAkkudoktor()
 feedintariff_energy_charts = FeedInTariffEnergyCharts()
 feedintariff_fixed = FeedInTariffFixed()
 feedintariff_import = FeedInTariffImport()
@@ -108,6 +110,7 @@ def prediction_providers() -> list[
         ElecPriceFixed,
         ElecPriceImport,
         ElecPriceTibber,
+        FeedInTariffAkkudoktor,
         FeedInTariffEnergyCharts,
         FeedInTariffFixed,
         FeedInTariffImport,
@@ -137,6 +140,7 @@ def prediction_providers() -> list[
         elecprice_fixed, \
         elecprice_import, \
         elecprice_tibber, \
+        feedintariff_akkudoktor, \
         feedintariff_energy_charts, \
         feedintariff_fixed, \
         feedintariff_import, \
@@ -162,6 +166,7 @@ def prediction_providers() -> list[
         elecprice_fixed,
         elecprice_import,
         elecprice_tibber,
+        feedintariff_akkudoktor,
         feedintariff_energy_charts,
         feedintariff_fixed,
         feedintariff_import,
@@ -192,6 +197,7 @@ class Prediction(PredictionContainer):
             ElecPriceFixed,
             ElecPriceImport,
             ElecPriceTibber,
+            FeedInTariffAkkudoktor,
             FeedInTariffEnergyCharts,
             FeedInTariffFixed,
             FeedInTariffImport,