[codex] Use tariff-specific MPSC PSCR factors

custom_components/dte_rates/__init__.py

@@ -10,7 +10,7 @@
 from homeassistant.exceptions import ConfigEntryNotReady
 from homeassistant.components import persistent_notification
 
-from .const import DOMAIN
+from .const import CONF_NET_METERING, CONF_SELECTED_RATE, DOMAIN
 from .coordinator import DteRateCoordinator
 from .rate_calculator import current_export_rate_cents, current_import_rate_cents, period_display_name
 
@@ -110,20 +110,22 @@ async def _handle_show_schedule_service(call) -> None:
         if coordinator is None:
             return
 
+        entry = next((e for e in hass.config_entries.async_entries(DOMAIN) if e.entry_id == entry_id), None)
         rate_code = call.data.get("rate_code")
         if rate_code:
             rate = coordinator.data.rates.get(rate_code)
         else:
-            entry = next((e for e in hass.config_entries.async_entries(DOMAIN) if e.entry_id == entry_id), None)
-            rate = coordinator.data.rates.get(entry.data.get("selected_rate")) if entry else None
+            rate = coordinator.data.rates.get(entry.data.get(CONF_SELECTED_RATE)) if entry else None
 
         if rate is None:
             return
 
         lines_by_season: dict[str, list[str]] = defaultdict(list)
+        net_metering = entry.data.get(CONF_NET_METERING, False) if entry else False
+        pscr_cents = getattr(coordinator.data, "pscr_rates", {}).get(rate.code)
         for period in sorted(rate.periods, key=lambda p: (p.season_name, p.period_name)):
             import_usd = float(current_import_rate_cents(period) / 100)
-            export_usd = float(current_export_rate_cents(period, False) / 100)
+            export_usd = float(current_export_rate_cents(period, net_metering, pscr_cents) / 100)
             lines_by_season[period.season_name].append(
                 f"{period_display_name(period)}: Import ${import_usd:.4f}/kWh | Export ${export_usd:.4f}/kWh"
             )

custom_components/dte_rates/config_flow.py

@@ -35,4 +35,18 @@ async def async_step_user(self, user_input: dict | None = None) -> FlowResult:
                 vol.Optional(CONF_NET_METERING, default=False): bool,
             }
         )
-        return self.async_show_form(step_id="user", data_schema=schema)
+        return self.async_show_form(
+            step_id="user",
+            data_schema=schema,
+            description_placeholders={
+                "rider18_status": _rider18_status(coordinator.data),
+            },
+        )
+
+
+def _rider18_status(rate_card) -> str:
+    count = len(getattr(rate_card, "pscr_rates", {}))
+    if count:
+        suffix = "tariff" if count == 1 else "tariffs"
+        return f"Rider 18 export credits use parsed generation rates plus MPSC PSCR factors loaded for {count} {suffix}."
+    return "Rider 18 export credits use parsed generation rates plus MPSC PSCR when the selected tariff has a PSCR factor."

custom_components/dte_rates/const.py

@@ -6,6 +6,10 @@
     "residential/Service-Request/pricing/residential-pricing-options/"
     "ResidentialElectricRateCard.pdf"
 )
+PSCR_RATE_BOOK_URL = (
+    "https://www.michigan.gov/-/media/Project/Websites/mpsc/consumer/"
+    "rate-books/electric/dte/dtee1cur.pdf"
+)
 
 UPDATE_INTERVAL = timedelta(days=7)
 
@@ -19,6 +23,13 @@
 ATTR_COMPONENTS = "components"
 ATTR_MONTHLY_COMPONENTS = "monthly_components"
 ATTR_SOURCE_URL = "source_url"
+ATTR_PSCR_CENTS = "pscr_cents"
+ATTR_PSCR_RATE_CODE = "pscr_rate_code"
+ATTR_PSCR_RATES = "pscr_rates"
+ATTR_PSCR_SOURCE_URL = "pscr_source_url"
+ATTR_RIDER18_EXPORT_AVAILABLE = "rider18_export_available"
+ATTR_EXPORT_RATE_SOURCE = "export_rate_source"
+ATTR_EXPORT_RATE_WARNING = "export_rate_warning"
 ATTR_CARD_EFFECTIVE_DATE = "card_effective_date"
 ATTR_SELECTED_RATE_AVAILABLE = "selected_rate_available"
 ATTR_WARNING = "warning"

custom_components/dte_rates/coordinator.py

@@ -7,9 +7,10 @@
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
 
-from .const import RATE_CARD_URL, UPDATE_INTERVAL
+from .const import PSCR_RATE_BOOK_URL, RATE_CARD_URL, UPDATE_INTERVAL
 from .models import ParsedRateCard
 from .pdf_parser import parse_rate_card_pdf
+from .pscr_parser import parse_pscr_rates_from_pdf
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -33,11 +34,46 @@ async def _async_update_data(self) -> ParsedRateCard:
         except Exception as err:
             raise UpdateFailed(f"Failed downloading DTE rate card: {err}") from err
 
+        pscr_bytes: bytes | None = None
         try:
-            return await self.hass.async_add_executor_job(
+            async with session.get(
+                PSCR_RATE_BOOK_URL,
+                headers={
+                    "Accept": "application/pdf,*/*",
+                    "User-Agent": "DTE-Rates-for-Home-Assistant/1.0",
+                },
+                timeout=60,
+            ) as resp:
+                resp.raise_for_status()
+                pscr_bytes = await resp.read()
+        except Exception as err:
+            _LOGGER.warning(
+                "Failed downloading MPSC DTE rate book; export rates will omit PSCR: %s",
+                err,
+            )
+
+        try:
+            parsed = await self.hass.async_add_executor_job(
                 parse_rate_card_pdf,
                 pdf_bytes,
                 RATE_CARD_URL,
             )
         except Exception as err:
             raise UpdateFailed(f"Failed parsing DTE rate card: {err}") from err
+
+        if pscr_bytes is None:
+            return parsed
+
+        try:
+            parsed.pscr_rates = await self.hass.async_add_executor_job(
+                parse_pscr_rates_from_pdf,
+                pscr_bytes,
+            )
+            parsed.pscr_source_url = PSCR_RATE_BOOK_URL
+        except Exception as err:
+            _LOGGER.warning(
+                "Failed parsing MPSC DTE rate book PSCR; export rates will omit PSCR: %s",
+                err,
+            )
+
+        return parsed

custom_components/dte_rates/models.py

@@ -50,3 +50,5 @@ class ParsedRateCard:
     effective_date: str | None
     rates: dict[str, RatePlan]
     raw_text_hash: str
+    pscr_rates: dict[str, Decimal] = field(default_factory=dict)
+    pscr_source_url: str | None = None

custom_components/dte_rates/pscr_parser.py

@@ -0,0 +1,52 @@
+from __future__ import annotations
+
+from decimal import Decimal
+import io
+import re
+
+from pypdf import PdfReader
+
+
+_RATE_ROW_RE = re.compile(
+    r"^\s*(?P<code>[A-Z]\d+(?:\.\d+)?)\s+.+?\s+(?P<pscr>-?\d+\.\d+)\s+\d+\.\d+",
+    re.IGNORECASE,
+)
+
+
+def parse_pscr_rates_from_pdf(pdf_bytes: bytes) -> dict[str, Decimal]:
+    """Extract current PSCR values by tariff code from the MPSC DTE electric rate book."""
+    reader = PdfReader(io.BytesIO(pdf_bytes))
+    text = "\n".join(page.extract_text() or "" for page in reader.pages)
+    lines = [re.sub(r"\s+", " ", line).strip() for line in text.splitlines()]
+
+    section = _power_supply_surcharge_lines(lines)
+    rates: dict[str, Decimal] = {}
+    for line in section:
+        match = _RATE_ROW_RE.match(line)
+        if match:
+            rates[match.group("code").upper()] = Decimal(match.group("pscr"))
+
+    if not rates:
+        raise ValueError("MPSC DTE rate book does not contain PSCR tariff rows")
+    return rates
+
+
+def _power_supply_surcharge_lines(lines: list[str]) -> list[str]:
+    start = None
+    for idx, line in enumerate(lines):
+        lower = line.lower()
+        if "c8.5 surcharges and credits applicable to power supply service" in lower:
+            start = idx
+            break
+
+    if start is None:
+        return lines
+
+    end = len(lines)
+    for idx in range(start + 1, len(lines)):
+        lower = lines[idx].lower()
+        if "c9 surcharges and credits applicable to delivery service" in lower:
+            end = idx
+            break
+
+    return lines[start:end]

custom_components/dte_rates/rate_calculator.py

@@ -65,15 +65,35 @@ def current_import_rate_cents(period: SeasonalPeriodRate) -> Decimal:
     return period.components.per_kwh_total
 
 
-def current_export_rate_cents(period: SeasonalPeriodRate, net_metering: bool) -> Decimal:
+def _component_total(period: SeasonalPeriodRate, markers: tuple[str, ...]) -> Decimal:
+    total = Decimal("0")
+    for key, value in period.components.per_kwh.items():
+        if any(marker in key for marker in markers):
+            total += value
+    return total
+
+
+def _has_component(period: SeasonalPeriodRate, markers: tuple[str, ...]) -> bool:
+    return any(any(marker in key for marker in markers) for key in period.components.per_kwh)
+
+
+def rider18_export_rate_cents(period: SeasonalPeriodRate, pscr_cents: Decimal | None = None) -> Decimal:
+    return _component_total(period, GENERATION_COMPONENT_MARKERS) + (pscr_cents or Decimal("0"))
+
+
+def rider18_export_formula_available(period: SeasonalPeriodRate, pscr_cents: Decimal | None = None) -> bool:
+    return _has_component(period, GENERATION_COMPONENT_MARKERS) and pscr_cents is not None
+
+
+def current_export_rate_cents(
+    period: SeasonalPeriodRate,
+    net_metering: bool,
+    pscr_cents: Decimal | None = None,
+) -> Decimal:
     if net_metering:
         return period.components.per_kwh_total
 
-    generation_only = Decimal("0")
-    for key, value in period.components.per_kwh.items():
-        if any(marker in key for marker in GENERATION_COMPONENT_MARKERS):
-            generation_only += value
-    return generation_only
+    return rider18_export_rate_cents(period, pscr_cents)
 
 
 def period_display_name(period: SeasonalPeriodRate) -> str:

custom_components/dte_rates/sensor.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from collections import defaultdict
+from decimal import Decimal
 
 from homeassistant.components.sensor import SensorDeviceClass, SensorEntity, SensorStateClass
 from homeassistant.components import persistent_notification
@@ -19,11 +20,18 @@
     ATTR_MONTHLY_COMPONENTS,
     ATTR_PERIOD,
     ATTR_CURRENT_RATE_NAME,
+    ATTR_EXPORT_RATE_SOURCE,
+    ATTR_EXPORT_RATE_WARNING,
     ATTR_NEXT_RATE_CHANGE,
     ATTR_NEXT_RATE_NAME,
     ATTR_NEXT_RATE_VALUE,
+    ATTR_PSCR_CENTS,
+    ATTR_PSCR_RATE_CODE,
+    ATTR_PSCR_RATES,
+    ATTR_PSCR_SOURCE_URL,
     ATTR_RATE_CODE,
     ATTR_RATE_NAME,
+    ATTR_RIDER18_EXPORT_AVAILABLE,
     ATTR_SCHEDULE_BY_SEASON,
     ATTR_SCHEDULE_TEXT,
     ATTR_SEASON,
@@ -41,6 +49,7 @@
     get_active_period,
     get_next_rate_change,
     period_display_name,
+    rider18_export_formula_available,
 )
 
 
@@ -103,6 +112,36 @@ def _active_period(self) -> SeasonalPeriodRate | None:
             return None
         return get_active_period(rate, dt_util.now())
 
+    def _pscr_cents_for_rate(self, rate: RatePlan | None = None) -> Decimal | None:
+        target_rate = rate or self._selected_rate()
+        if target_rate is None:
+            return None
+        return getattr(self.coordinator.data, "pscr_rates", {}).get(target_rate.code)
+
+    def _export_rate_cents(self, period: SeasonalPeriodRate):
+        return current_export_rate_cents(
+            period,
+            self._entry.data.get(CONF_NET_METERING, False),
+            self._pscr_cents_for_rate(),
+        )
+
+    def _export_rate_source(self, period: SeasonalPeriodRate) -> str:
+        if self._entry.data.get(CONF_NET_METERING, False):
+            return "net_metering"
+        if rider18_export_formula_available(period, self._pscr_cents_for_rate()):
+            return "rider18_formula"
+        return "rider18_formula_incomplete"
+
+    def _export_rate_warning(self, period: SeasonalPeriodRate) -> str | None:
+        if self._entry.data.get(CONF_NET_METERING, False):
+            return None
+        if rider18_export_formula_available(period, self._pscr_cents_for_rate()):
+            return None
+        return (
+            "Rider 18 formula is missing a generation component or PSCR value "
+            "for the active period; using the available formula components only."
+        )
+
     def _warning(self) -> str | None:
         selected = self._entry.data[CONF_SELECTED_RATE]
         if selected not in self.coordinator.data.rates:
@@ -118,6 +157,16 @@ def _base_attributes(self) -> dict:
             ATTR_SOURCE_URL: self.coordinator.data.source_url,
             ATTR_CARD_EFFECTIVE_DATE: self.coordinator.data.effective_date,
         }
+        pscr_cents = self._pscr_cents_for_rate()
+        if pscr_cents is not None:
+            attrs[ATTR_PSCR_CENTS] = float(pscr_cents)
+            rate = self._selected_rate()
+            if rate is not None:
+                attrs[ATTR_PSCR_RATE_CODE] = rate.code
+        if self.coordinator.data.pscr_rates:
+            attrs[ATTR_PSCR_RATES] = {code: float(value) for code, value in self.coordinator.data.pscr_rates.items()}
+        if self.coordinator.data.pscr_source_url:
+            attrs[ATTR_PSCR_SOURCE_URL] = self.coordinator.data.pscr_source_url
 
         rate = self._selected_rate()
         period = self._active_period()
@@ -260,13 +309,19 @@ def native_value(self) -> float | None:
     def extra_state_attributes(self) -> dict:
         attrs = self._base_attributes()
         attrs[CONF_NET_METERING] = self._entry.data.get(CONF_NET_METERING, False)
+        period = self._active_period()
+        if period is not None:
+            attrs[ATTR_EXPORT_RATE_SOURCE] = self._export_rate_source(period)
+            attrs[ATTR_RIDER18_EXPORT_AVAILABLE] = rider18_export_formula_available(period, self._pscr_cents_for_rate())
+            warning = self._export_rate_warning(period)
+            if warning is not None:
+                attrs[ATTR_EXPORT_RATE_WARNING] = warning
         return attrs
 
     def _period_value_usd(self, period: SeasonalPeriodRate | None) -> float | None:
         if period is None:
             return None
-        cents = current_export_rate_cents(period, self._entry.data.get(CONF_NET_METERING, False))
-        return float(cents / 100)
+        return float(self._export_rate_cents(period) / 100)
 
 
 class DteCurrentRateNameSensor(_DteBaseRateSensor):
@@ -328,7 +383,6 @@ def extra_state_attributes(self) -> dict:
 
     def _schedule_rows(self, rate: RatePlan) -> list[dict]:
         rows: list[dict] = []
-        net_metering = self._entry.data.get(CONF_NET_METERING, False)
         for period in sorted(rate.periods, key=lambda p: (p.season_name, p.period_name)):
             rows.append(
                 {
@@ -337,7 +391,7 @@ def _schedule_rows(self, rate: RatePlan) -> list[dict]:
                     "name": period_display_name(period),
                     "time_window": self._window_summary(period),
                     "import_usd_per_kwh": round(float(current_import_rate_cents(period) / 100), 6),
-                    "export_usd_per_kwh": round(float(current_export_rate_cents(period, net_metering) / 100), 6),
+                    "export_usd_per_kwh": round(float(self._export_rate_cents(period) / 100), 6),
                 }
             )
         return rows

custom_components/dte_rates/strings.json

@@ -3,7 +3,7 @@
     "step": {
       "user": {
         "title": "DTE Residential Rates",
-        "description": "Choose your DTE residential electric pricing plan.",
+        "description": "Choose your DTE residential electric pricing plan.\n\n{rider18_status}",
         "data": {
           "selected_rate": "Rate plan",
           "net_metering": "Net metering enabled"

custom_components/dte_rates/translations/en.json

@@ -3,7 +3,7 @@
     "step": {
       "user": {
         "title": "DTE Residential Rates",
-        "description": "Choose your DTE residential electric pricing plan.",
+        "description": "Choose your DTE residential electric pricing plan.\n\n{rider18_status}",
         "data": {
           "selected_rate": "Rate plan",
           "net_metering": "Net metering enabled"

docs/README.md

@@ -0,0 +1,9 @@
+# Project Notes
+
+This directory stores research and implementation notes that support changes to the DTE Rates integration.
+
+## Structure
+
+- `research/` - Source observations, mapping decisions, and implementation notes gathered while working on external rate-card or calculator data.
+
+Use these notes as context for why parsers map external DTE documents into Home Assistant entities. The code remains the source of truth for behavior.