refactor: drop PV synthesis, model raw P1 net signal directly

The simulator used to reconstruct "gross household demand" by adding
back a synthesized PV trace (irradiance × kWp peak-match) to the P1 net
meter, then re-subtract a different synthesized PV per scenario. That
reconstruction was leaky — Michiel's horizontal pyranometer is at a
different location and orientation than dad's SE-facing array, so the
synthesis can't reproduce dad's actual production curve. Result: 511
hours of negative "gross demand" and phantom export inflation up to
~6 kW peak in scenarios where pv_kwp ≠ 3.

New shape: simulator works on a single signed signal, raw_demand_kw
(the P1 reading as recorded). No solar synthesis. Whatever the meter
shows is the input.

Concretely:
  - sim.py: drop synthesize_pv, reconstruct_gross_demand,
    schedule_with_planning_pv, no_foresight_schedule, groundhog_schedule,
    _oracle_daily_schedule_legacy. Rename column convention demand_kwh →
    raw_demand_kw. Plug-in discharge cap becomes max(0, raw_demand_kw).
  - web.py: drop pv_kwp/pv_yield/strategy form params. Demand slider
    now applies as an *additive* baseline shift (not multiplicative —
    multiplying scaled the export bursts too, which is wrong since dad's
    PV stays the same regardless of household consumption). Default
    demand_kwh = 2325 (dad's actual full-year net per his quote;
    extrapolated 8-month window comes out to ~1515, partial coverage).
    Saturation metric now measures (surplus ≥ pc_max), not (charge ≥
    pc_max) — the latter conflated arbitrage top-off with power-bottleneck.
  - templates/index.html: drop PV input, drop strategy radios, drop
    irradiance chart. Modal charts collapsed from 4 to 3: price, net
    meter (toggles between with/without battery), SoC.
  - app.js: mirror the above, drop pv_kwp/strategy plumbing.
  - tests: rebase fixtures on raw_demand_kw, drop synthesize_pv test.
  - scripts: drop --pv-kwp/--pv-yield flags throughout, switch column
    references to raw_demand_kw.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

data/raw/extra_batteries.json

@@ -13,5 +13,20 @@
     "recommended": false,
     "installation": "plugin",
     "image_url": ""
+  },
+  {
+    "id": -1,
+    "title": "Zendure SolarFlow 2400AC 5.8 kWh",
+    "url": "https://www.solar-outlet.nl/zendure-solarflow-2400ac-thuisbatterijset-58-kwh.html",
+    "brand": "Zendure",
+    "brand_slug": "zendure",
+    "capacity": 5.8,
+    "power_continuous": 2400,
+    "price": 1759,
+    "price_per_kwh": 303.3,
+    "review_score": null,
+    "recommended": false,
+    "installation": "plugin",
+    "image_url": ""
   }
 ]

scripts/battery_leaderboard.py

@@ -2,10 +2,11 @@
 """Run every battery in the catalog through both calculators and rank by payback.
 
 Default scenario matches the dynamic-mode store-test:
-  4000 kWh/yr demand, avg retail €0.25, no PV, no saldering, 3% inflation.
+  4000 kWh/yr net demand, avg retail €0.25, no saldering, 3% inflation.
 
-Override with CLI flags to test a different scenario (e.g., dad's situation
+The simulator works on the raw P1 net-meter trace — whatever PV is on the
-with --pv-kwp 3.0). Output: data/processed/battery_leaderboard.csv.
+roof is already netted in. To model a different PV setup, swap the input
+data, not a CLI flag. Output: data/processed/battery_leaderboard.csv.
 """
 from __future__ import annotations
 
@@ -19,7 +20,6 @@ from pluginbattery.sim import (
     load_hourly,
     oracle_daily_schedule,
     simulate,
-    synthesize_pv,
 )
 from pluginbattery.store_calc import (
     Scenario,
@@ -36,8 +36,6 @@ def main() -> None:
     p.add_argument("--retail", type=float, default=0.25)
     p.add_argument("--demand", type=float, default=4000.0)
     p.add_argument("--eta", type=float, default=0.88)
-    p.add_argument("--pv-kwp", type=float, default=0.0)
-    p.add_argument("--pv-yield", type=float, default=875.0)
     p.add_argument("--saldering", action="store_true")
     p.add_argument("--inflation", type=float, default=0.03)
     p.add_argument("--top", type=int, default=20, help="How many rows to print")
@@ -46,15 +44,14 @@ def main() -> None:
     # ─── Load and prep the simulation data once ────────────────────────
     base = load_hourly("data/raw"); base = apply_nl_tariff(base)
     df = base.copy()
-    annual_demand = base["demand_kwh"].sum() * (8766.0 / len(base))
+    annual_net_demand = base["raw_demand_kw"].sum() * (8766.0 / len(base))
-    df["demand_kwh"] = base["demand_kwh"] * (args.demand / annual_demand)
+    df["raw_demand_kw"] = base["raw_demand_kw"] * (args.demand / annual_net_demand)
     scale = args.retail / base["eur_per_kwh"].mean()
     df["eur_per_kwh"] = base["eur_per_kwh"] * scale
     df["epex_eur_per_kwh"] = base["epex_eur_per_kwh"] * scale
-    if args.pv_kwp > 0:
-        df = synthesize_pv(df, kwp=args.pv_kwp,
-                           target_kwh_per_kwp_per_year=args.pv_yield)
     df["export_eur_per_kwh"] = df["eur_per_kwh"] if args.saldering else 0.0
+    # Existing-PV export visible at the meter (any hour where raw_demand_kw < 0).
+    has_existing_pv = bool((df["raw_demand_kw"] < 0).any())
 
     avg_epex = float(df["epex_eur_per_kwh"].mean())
     store_params = StoreParams(avg_epex_eur_per_kwh=avg_epex)
@@ -80,8 +77,9 @@ def main() -> None:
     # Cache LP results by (capacity, power) — many batteries share identical specs.
     lp_cache: dict[tuple[float, float], float] = {}
 
-    print(f"Scenario: demand {args.demand:.0f} kWh/yr, avg retail €{args.retail}, "
+    print(f"Scenario: net demand {args.demand:.0f} kWh/yr, avg retail €{args.retail}, "
-          f"PV {args.pv_kwp} kWp, saldering={args.saldering}, inflation {args.inflation*100:.1f}%/yr")
+          f"existing-PV exports={'yes' if has_existing_pv else 'no'}, "
+          f"saldering={args.saldering}, inflation {args.inflation*100:.1f}%/yr")
     print(f"Running {len(rows_in)} batteries (caching by (capacity, power))...")
     print()
 
@@ -104,7 +102,7 @@ def main() -> None:
         scn = Scenario(
             capacity_kwh=r["capacity_kwh"], max_charge_kw=r["power_kw"],
             battery_cost_eur=r["price_eur"], avg_retail_eur_per_kwh=args.retail,
-            has_pv=args.pv_kwp > 0, has_saldering=args.saldering, dynamic_rate=True,
+            has_pv=has_existing_pv, has_saldering=args.saldering, dynamic_rate=True,
         )
         sq = store_quote(scn, store_params, inflation=args.inflation)
 

scripts/capacity_sweep.py

@@ -48,9 +48,9 @@ def main() -> None:
     base = load_hourly("data/raw"); base = apply_nl_tariff(base)
 
     # Scale to the test scenario.
-    annual_demand = base["demand_kwh"].sum() * (8766.0 / len(base))
+    annual_demand = base["raw_demand_kw"].sum() * (8766.0 / len(base))
     df = base.copy()
-    df["demand_kwh"] = base["demand_kwh"] * (args.demand / annual_demand)
+    df["raw_demand_kw"] = base["raw_demand_kw"] * (args.demand / annual_demand)
     scale = args.retail / base["eur_per_kwh"].mean()
     df["eur_per_kwh"] = base["eur_per_kwh"] * scale
     df["epex_eur_per_kwh"] = base["epex_eur_per_kwh"] * scale

scripts/compare_batteries.py

@@ -1,9 +1,10 @@
 #!/usr/bin/env python3
-"""Run the 24h-foresight oracle for several battery configs and print a comparison.
+"""Run the price-arbitrage oracle for several battery configs and print a comparison.
 
 Saves per-hour CSVs for each config plus a summary table. Tariff: NL consumer.
-With --pv-kwp > 0, synthesizes PV output from horizontal irradiance and treats
+The simulator works on the raw P1 net-meter trace — whatever PV is on the
-saldering as full export credit at consumer price (NL pre-2027).
+roof is already netted in. Existing-PV exports show up as negative
+``raw_demand_kw`` and are absorbed by the battery before crossing the meter.
 """
 from __future__ import annotations
 
@@ -18,7 +19,6 @@ from pluginbattery.sim import (
     load_hourly,
     oracle_daily_schedule,
     simulate,
-    synthesize_pv,
 )
 
 CONFIGS = [
@@ -79,14 +79,6 @@ def payback_years(year1_savings: float, cost: float, inflation: float = 0.0) ->
 
 def main() -> None:
     parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument(
-        "--pv-kwp", type=float, default=0.0,
-        help="PV system size in kWp. 0 = no solar (default).",
-    )
-    parser.add_argument(
-        "--pv-target", type=float, default=900.0,
-        help="Calibrate PV to this annual yield in kWh/kWp/year. Default 900 = NL norm.",
-    )
     parser.add_argument(
         "--saldering", choices=["none", "full"], default="none",
         help="'full' = export at consumer price (NL pre-2027). "
@@ -121,11 +113,12 @@ def main() -> None:
     elif args.price_mult != 1.0:
         df["eur_per_kwh"] = df["eur_per_kwh"] * args.price_mult
 
-    pv_note = "no solar"
+    # Existing PV (if any) is already in raw_demand_kw via the meter signal.
-    if args.pv_kwp > 0:
+    annual_export = float(-df["raw_demand_kw"].clip(upper=0).sum() * 8766.0 / len(df))
-        df = synthesize_pv(df, kwp=args.pv_kwp, target_kwh_per_kwp_per_year=args.pv_target)
+    if annual_export > 1.0:
-        pv_kwh_year = float(df["pv_kwh"].sum() * 8766.0 / len(df))
+        pv_note = f"{annual_export:.0f} kWh/yr exported at meter (existing PV)"
-        pv_note = f"{args.pv_kwp:.1f} kWp PV, calibrated to {pv_kwh_year:.0f} kWh/yr"
+    else:
+        pv_note = "no measurable existing PV in the data"
 
     if args.export_rate is not None:
         df["export_eur_per_kwh"] = float(args.export_rate)
@@ -146,10 +139,10 @@ def main() -> None:
     print(f"Tariff: import = {price_note}; {sald_note}")
     if args.price_inflation > 0:
         print(f"Payback uses {args.price_inflation*100:.1f}%/yr energy-price inflation")
-    print(f"Solar : {pv_note}\n")
+    print(f"Meter : {pv_note}\n")
 
     # Headline figures with no battery, just for context.
-    g_no = df["demand_kwh"] - df.get("pv_kwh", 0)
+    g_no = df["raw_demand_kw"]
     imp_p = df["eur_per_kwh"]
     exp_p = df.get("export_eur_per_kwh", df["eur_per_kwh"])
     cost_no_battery_total = float((g_no.where(g_no > 0, 0) * imp_p +
@@ -187,7 +180,6 @@ def main() -> None:
                 "max_charge_kw": battery.max_charge_kw,
                 "max_discharge_kw": battery.max_discharge_kw,
                 "price_eur": price,
-                "pv_kwp": args.pv_kwp,
                 "saldering": args.saldering,
                 "annual_savings_eur": round(savings, 2),
                 "kwh_shifted": round(kwh_shifted, 1),

scripts/compare_with_store.py

@@ -10,8 +10,8 @@ Examples:
     python scripts/compare_with_store.py --capacity 5.12 --power 0.8 --cost 1339 --retail 0.25
     python scripts/compare_with_store.py --capacity 5.12 --power 2.5 --cost 1339 --retail 0.25
 
-    # PV scenario, fixed retail, no saldering:
+    # Fixed retail, no saldering:
-    python scripts/compare_with_store.py --pv-kwp 3.0 --fixed --retail 0.28
+    python scripts/compare_with_store.py --fixed --retail 0.28
 """
 from __future__ import annotations
 
@@ -23,7 +23,6 @@ from pluginbattery.sim import (
     load_hourly,
     oracle_daily_schedule,
     simulate,
-    synthesize_pv,
 )
 from pluginbattery.store_calc import (
     Scenario,
@@ -47,10 +46,6 @@ def main() -> None:
                    help="Fixed-rate mode (no time-of-day variation; kills arbitrage)")
     p.add_argument("--saldering", action="store_true",
                    help="Full saldering on (export = retail). Default: no saldering.")
-    # Solar
-    p.add_argument("--pv-kwp", type=float, default=0.0, help="PV size in kWp; 0 = no PV")
-    p.add_argument("--pv-yield", type=float, default=875.0,
-                   help="Annual PV yield in kWh/kWp (store uses 875 in their footer)")
     # Inflation
     p.add_argument("--inflation", type=float, default=0.03)
     args = p.parse_args()
@@ -59,9 +54,10 @@ def main() -> None:
     base = load_hourly("data/raw"); base = apply_nl_tariff(base)
     df = base.copy()
 
-    # Demand scaling.
+    # Demand scaling — scale the entire signed signal so existing-PV exports
-    annual_demand = base["demand_kwh"].sum() * (8766.0 / len(base))
+    # scale with the household.
-    df["demand_kwh"] = base["demand_kwh"] * (args.demand / annual_demand)
+    annual_net_demand = base["raw_demand_kw"].sum() * (8766.0 / len(base))
+    df["raw_demand_kw"] = base["raw_demand_kw"] * (args.demand / annual_net_demand)
 
     # Retail price.
     if args.fixed:
@@ -73,16 +69,14 @@ def main() -> None:
         df["epex_eur_per_kwh"] = base["epex_eur_per_kwh"] * scale
         epex_in_use = df["epex_eur_per_kwh"]
 
-    # PV.
-    if args.pv_kwp > 0:
-        df = synthesize_pv(df, kwp=args.pv_kwp, target_kwh_per_kwp_per_year=args.pv_yield)
-
     # Saldering.
     if args.saldering:
         df["export_eur_per_kwh"] = df["eur_per_kwh"]
     else:
         df["export_eur_per_kwh"] = 0.0  # post-saldering default in this script
 
+    has_existing_pv = bool((df["raw_demand_kw"] < 0).any())
+
     bat = Battery(
         capacity_kwh=args.capacity,
         max_charge_kw=args.power,
@@ -102,7 +96,7 @@ def main() -> None:
         max_charge_kw=args.power,
         battery_cost_eur=args.cost,
         avg_retail_eur_per_kwh=args.retail,
-        has_pv=args.pv_kwp > 0,
+        has_pv=has_existing_pv,
         has_saldering=args.saldering,
         dynamic_rate=not args.fixed,
     )
@@ -114,9 +108,8 @@ def main() -> None:
     print(f"  Tariff         : avg retail €{args.retail}, "
           f"{'FIXED' if args.fixed else 'DYNAMIC'} rate, "
           f"{'WITH' if args.saldering else 'NO'} saldering")
-    print(f"  PV             : {args.pv_kwp} kWp"
+    print(f"  PV             : {'existing PV in meter signal' if has_existing_pv else 'no measurable existing PV'}")
-          f"{' @ ' + str(args.pv_yield) + ' kWh/kWp/yr' if args.pv_kwp else ''}")
+    print(f"  Net demand     : {args.demand:.0f} kWh/yr")
-    print(f"  Demand         : {args.demand:.0f} kWh/yr")
     print(f"  Inflation      : {args.inflation*100:.1f}%/yr")
     print()
     print(f"{'':22s}  {'year-1 €':>10s}  {'payback':>9s}")

scripts/import_dad_p1.py

@@ -6,9 +6,9 @@ meter readings, every 15 min, 2025 calendar year, Europe/Amsterdam local time).
 
 Output: data/raw/p1_hourly.csv (timestamp UTC, power_w mean over hour). Net
 of PV exports — `power_w` can be negative when his solar exceeded household
-demand. The simulator interprets `demand_kwh = power_w / 1000`, and a plug-in
+demand. The simulator interprets `raw_demand_kw = power_w / 1000`, and a
-battery's discharge cap `max(0, demand - pv)` correctly handles negative
+plug-in battery's discharge cap `max(0, raw_demand_kw)` correctly forbids
-demand by forbidding discharge during surplus hours.
+discharge during net-export hours (the meter is already flowing the wrong way).
 
 The simulator's window is 2023-09-01 → 2024-09-01 UTC. Dad's data is the
 2025 calendar year. We align by (month, day, hour) so seasonal patterns

scripts/timeline_inspect.py

@@ -46,8 +46,8 @@ def main() -> None:
     # ─── Build the same df the web app sees ───
     base = apply_nl_tariff(load_hourly("data/raw"))
     df = base.copy()
-    annual = base["demand_kwh"].sum() * 8766 / len(base)
+    annual = base["raw_demand_kw"].sum() * 8766 / len(base)
-    df["demand_kwh"] = base["demand_kwh"] * (args.demand_kwh / annual)
+    df["raw_demand_kw"] = base["raw_demand_kw"] * (args.demand_kwh / annual)
     scale = args.retail / base["eur_per_kwh"].mean()
     df["eur_per_kwh"] = base["eur_per_kwh"] * scale
     df["epex_eur_per_kwh"] = base["epex_eur_per_kwh"] * scale
@@ -62,10 +62,10 @@ def main() -> None:
     out = out.assign(
         import_kwh=np.maximum(0.0, g),
         export_kwh=np.maximum(0.0, -g),
-        no_bat_grid=out["demand_kwh"],   # equals the original net since pv=0
+        no_bat_grid=out["raw_demand_kw"],   # equals the original net since pv=0
-        cost_no_battery_eur=np.where(out["demand_kwh"] > 0,
+        cost_no_battery_eur=np.where(out["raw_demand_kw"] > 0,
-                                     out["demand_kwh"] * out["eur_per_kwh"],
+                                     out["raw_demand_kw"] * out["eur_per_kwh"],
-                                     out["demand_kwh"] * out["export_eur_per_kwh"]),
+                                     out["raw_demand_kw"] * out["export_eur_per_kwh"]),
         cost_with_battery_eur=np.where(g > 0, g * out["eur_per_kwh"],
                                        g * out["export_eur_per_kwh"]),
     )
@@ -89,7 +89,7 @@ def main() -> None:
         print(f"   {'hr':>2s}  {'price':>5s}  {'no-bat meter':>15s}  "
               f"{'charge':>7s}  {'disch':>7s}  {'SoC':>5s}  {'with-bat meter':>16s}  {'sav':>6s}")
         for ts, r in day.iterrows():
-            net_no = r["demand_kwh"]
+            net_no = r["raw_demand_kw"]
             mark = "↓ exp" if net_no < -0.01 else "↑ imp" if net_no > 0.01 else "·"
             grid = r["grid_kwh_with_battery"]
             grid_mark = "↓ exp" if grid < -0.01 else "↑ imp" if grid > 0.01 else "·"
@@ -97,8 +97,8 @@ def main() -> None:
                   f"{net_no:+7.2f} {mark:5s}  "
                   f"{r['charge_kwh']:>6.2f}  {r['discharge_kwh']:>6.2f}  "
                   f"{r['soc_kwh']:>4.2f}  {grid:+8.2f} {grid_mark:5s}  €{r['savings_eur']:+5.2f}")
-        d_imp_no = max(0.0, day['demand_kwh'].clip(lower=0).sum())
+        d_imp_no = max(0.0, day['raw_demand_kw'].clip(lower=0).sum())
-        d_exp_no = -day['demand_kwh'].clip(upper=0).sum()
+        d_exp_no = -day['raw_demand_kw'].clip(upper=0).sum()
         d_imp_yes = day['import_kwh'].sum()
         d_exp_yes = day['export_kwh'].sum()
         d_sav = day['savings_eur'].sum()
@@ -113,8 +113,8 @@ def main() -> None:
     week_savings = win["savings_eur"].sum()
     week_charge  = win["charge_kwh"].sum()
     week_disch   = win["discharge_kwh"].sum()
-    week_surplus = (-win["demand_kwh"].clip(upper=0)).sum()
+    week_surplus = (-win["raw_demand_kw"].clip(upper=0)).sum()
-    week_imports = win["demand_kwh"].clip(lower=0).sum()
+    week_imports = win["raw_demand_kw"].clip(lower=0).sum()
 
     annual_savings = out["savings_eur"].sum()
     annualised = week_savings * 365.25 / args.days

src/pluginbattery/sim.py

@@ -1,13 +1,22 @@
 """Hourly home-battery simulator.
 
+The simulator operates on a single signed signal: ``raw_demand_kw``, the P1
+net-meter reading. Positive = importing, negative = exporting (e.g. from
+existing rooftop PV already netted at the meter). We do **not** model solar
+as a separate signal — whatever the meter shows is the input. To ask "what
+if the PV were different" you need actual measurements of that situation;
+synthesizing PV from a remote irradiance sensor was tried and didn't survive
+contact with reality (different roof, different orientation, different cloud
+cover).
+
 Three pieces:
   - load_hourly():            CSVs in -> single hourly DataFrame, missing-hour rows dropped.
   - simulate(df, bat, sched): walks SoC hour by hour, clamps to physical limits,
                               returns trajectory + grid flows + costs.
-  - oracle_daily_schedule():  solves a 24h LP per UTC day for perfect-foresight
+  - oracle_daily_schedule():  greedy self-consumption (Pass 1) + perfect-foresight
-                              within-day arbitrage. No cross-day shifting.
+                              per-day price arbitrage (Pass 2).
 
-Anything that decides what to do (oracle, rules, ML) returns a (n, 2) schedule of
+Anything that decides what to do returns a (n, 2) schedule of
 [charge_kwh, discharge_kwh]; simulate() is the single source of truth for state.
 """
 from __future__ import annotations
@@ -17,7 +26,6 @@ from pathlib import Path
 
 import numpy as np
 import pandas as pd
-from scipy.optimize import linprog
 
 
 @dataclass(frozen=True)
@@ -40,39 +48,6 @@ ECOFLOW_STREAM_AC = Battery(
 )
 
 
-def synthesize_pv(
-    df: pd.DataFrame,
-    kwp: float,
-    target_kwh_per_kwp_per_year: float = 900.0,
-    irradiance_cap_w_m2: float = 1000.0,
-) -> pd.DataFrame:
-    """Synthesize hourly PV output (kWh) from horizontal irradiance.
-
-    Output shape follows the irradiance signal (so timing tracks real local
-    weather). The total is calibrated to `target_kwh_per_kwp_per_year` —
-    900 kWh/kWp/year is the NL norm for a south-facing 35° roof. This
-    sidesteps the question "what's the right system factor?" and absorbs any
-    sensor bias automatically: if the irradiance reads 22% low, the implied
-    factor goes up to compensate.
-
-    Outlier handling: irradiance clipped to [0, irradiance_cap_w_m2].
-    """
-    out = df.copy()
-    irr = out["irradiance_w_m2"].clip(lower=0.0, upper=irradiance_cap_w_m2)
-
-    # Annualised horizontal irradiance density for *this* dataset, kWh/m²/year.
-    hours = len(df)
-    annual_irradiance_kwh_m2 = (irr.sum() / 1000.0) * (8766.0 / hours)
-    if annual_irradiance_kwh_m2 <= 0:
-        raise ValueError("Irradiance data is all zero or negative.")
-
-    system_factor = target_kwh_per_kwp_per_year / annual_irradiance_kwh_m2
-    out["pv_kwh"] = irr / 1000.0 * kwp * system_factor
-    out.attrs["pv_system_factor"] = system_factor
-    out.attrs["pv_annual_kwh"] = float(out["pv_kwh"].sum() * 8766.0 / hours)
-    return out
-
-
 def apply_nl_tariff(
     df: pd.DataFrame,
     vat: float = 0.21,
@@ -95,17 +70,16 @@ def apply_nl_tariff(
 
 
 def load_hourly(data_dir: Path | str = "data/raw") -> pd.DataFrame:
-    """Read prices/P1/solar CSVs into one hourly DataFrame indexed by UTC timestamp.
+    """Read prices + P1 CSVs into one hourly DataFrame indexed by UTC timestamp.
 
-    Drops every hour where any of the three signals is missing (inner join +
+    Drops every hour where either signal is missing (inner join + dropna).
-    dropna). Adds a derived `demand_kwh` column = power_w / 1000 (since power_w
+    Adds ``raw_demand_kw = power_w / 1000`` — the signed P1 net meter
-    is the hour mean and 1 W * 1 h = 1 Wh).
+    reading. Negative = exporting, positive = importing.
     """
     data_dir = Path(data_dir)
     files = {
         "eur_per_kwh": "prices_hourly.csv",
         "power_w":     "p1_hourly.csv",
-        "irradiance_w_m2": "solar_hourly.csv",
     }
     parts = []
     for col, fname in files.items():
@@ -117,7 +91,7 @@ def load_hourly(data_dir: Path | str = "data/raw") -> pd.DataFrame:
             sub.index = sub.index.tz_convert("UTC")
         parts.append(sub[[col]])
     df = pd.concat(parts, axis=1, join="inner").dropna().sort_index()
-    df["demand_kwh"] = df["power_w"] / 1000.0
+    df["raw_demand_kw"] = df["power_w"] / 1000.0
     return df
 
 
@@ -129,13 +103,13 @@ def simulate(df: pd.DataFrame, battery: Battery, schedule: np.ndarray) -> pd.Dat
               authoritative state engine, the schedule is only a *request*.
 
     Column conventions read by this function:
-      - eur_per_kwh:        import price (always required)
+      - raw_demand_kw:      signed meter reading (always required). +import, −export.
-      - pv_kwh:             optional, hourly PV production
+      - eur_per_kwh:        import price (always required).
       - export_eur_per_kwh: optional, export credit price. Defaults to
                             eur_per_kwh (full saldering) if missing.
 
-    Per hour: `g = demand − pv + charge − discharge`. Cost uses the import
+    Per hour: ``g = raw_demand_kw + charge − discharge``. Cost uses the
-    price when g > 0, the export price when g < 0.
+    import price when g > 0, the export price when g < 0.
     """
     n = len(df)
     if schedule.shape != (n, 2):
@@ -151,8 +125,7 @@ def simulate(df: pd.DataFrame, battery: Battery, schedule: np.ndarray) -> pd.Dat
     d_arr = np.empty(n)
     soc_arr = np.empty(n)
 
-    demand = df["demand_kwh"].to_numpy()
+    raw = df["raw_demand_kw"].to_numpy()
-    pv = df["pv_kwh"].to_numpy() if "pv_kwh" in df.columns else np.zeros(n)
     requested_c = schedule[:, 0]
     requested_d = schedule[:, 1]
 
@@ -166,8 +139,8 @@ def simulate(df: pd.DataFrame, battery: Battery, schedule: np.ndarray) -> pd.Dat
         d = max(0.0, min(requested_d[t], pd_max, avail_kwh_grid))
         if not battery.allows_export:
             # Plug-in: cannot push current backwards through the meter.
-            # Discharge can't exceed the *net* demand after solar.
+            # Discharge can't take the net flow below zero.
-            d = min(d, max(0.0, demand[t] - pv[t]))
+            d = min(d, max(0.0, raw[t]))
 
         soc = soc + c * eta - d / eta
         # Numerical guard rail for floating point drift.
@@ -178,8 +151,6 @@ def simulate(df: pd.DataFrame, battery: Battery, schedule: np.ndarray) -> pd.Dat
         soc_arr[t] = soc
 
     out = df.copy()
-    if "pv_kwh" not in out.columns:
-        out["pv_kwh"] = 0.0
     out["charge_kwh"] = c_arr
     out["discharge_kwh"] = d_arr
     out["soc_kwh"] = soc_arr
@@ -190,7 +161,7 @@ def simulate(df: pd.DataFrame, battery: Battery, schedule: np.ndarray) -> pd.Dat
     else:
         export_price = import_price  # default = full saldering
 
-    g_no = (out["demand_kwh"] - out["pv_kwh"]).to_numpy()
+    g_no = raw
     g_yes = g_no + c_arr - d_arr
 
     out["grid_kwh_no_battery"] = g_no
@@ -201,32 +172,12 @@ def simulate(df: pd.DataFrame, battery: Battery, schedule: np.ndarray) -> pd.Dat
     return out
 
 
-def oracle_daily_schedule(df: pd.DataFrame, battery: Battery) -> np.ndarray:
+def _pass1_reactive(df: pd.DataFrame, battery: Battery) -> tuple[np.ndarray, np.ndarray]:
-    """Two-pass dispatch: greedy self-consumption + daily grid arbitrage.
+    """Greedy self-consumption: charge from surplus, discharge to cover demand.
 
-    This matches what a modern plug-in battery with smart-charging firmware
+    Pure function of raw_demand_kw. No foresight — exactly the "default
-    (Tibber controllers, Marstek 'Smart Charging' mode, EcoFlow with dynamic
+    mode" behaviour of every plug-in battery firmware out there.
-    tariff integration) actually does in practice — and it always produces
+    Returns (schedule, soc) where soc has length n+1 (soc[0] = initial).
-    visually intuitive schedules without LP indifference artefacts.
-
-    Pass 1 (greedy self-consumption):
-        For each hour in order, charge from any meter export, discharge to
-        cover any meter import. Exactly the "default mode" behaviour.
-
-    Pass 2 (per-UTC-day arbitrage on residual capacity):
-        For each day, repeatedly find the most profitable
-        cheap-hour → expensive-hour pair, considering:
-          - Both charge and discharge already have residual room (power
-            and SoC headroom).
-          - Discharge fits within demand at the expensive hour (plug-in
-            cannot push to grid; allows_export=True relaxes this).
-          - Profit per shifted kWh = η · price[discharge] − price[charge] / η
-            must be positive.
-        Execute the most profitable, update SoC trajectory, repeat. Stops
-        when no profitable cycle remains for that day.
-
-    Pass 1 is order-of-day dependent (real firmware acts moment-by-moment),
-    so it always runs first. Pass 2 sees what's left.
     """
     cap = battery.capacity_kwh
     pc_max = battery.max_charge_kw
@@ -234,38 +185,50 @@ def oracle_daily_schedule(df: pd.DataFrame, battery: Battery) -> np.ndarray:
     eta = battery.round_trip_eff ** 0.5
     n = len(df)
 
-    demand = df["demand_kwh"].to_numpy()
+    raw = df["raw_demand_kw"].to_numpy()
-    pv = df["pv_kwh"].to_numpy() if "pv_kwh" in df.columns else np.zeros(n)
-    net = demand - pv
-    prices = df["eur_per_kwh"].to_numpy()
 
     schedule = np.zeros((n, 2))
     soc = np.zeros(n + 1)
     soc[0] = battery.initial_soc_kwh
 
-    # ── Pass 1: greedy self-consumption ─────────────────────────────────
     for t in range(n):
-        if net[t] < -1e-9:                                 # exporting
+        if raw[t] < -1e-9:                                 # exporting (surplus from existing PV)
-            surplus = -net[t]
+            surplus = -raw[t]
             room = (cap - soc[t]) / eta if eta > 0 else 0.0
             c = max(0.0, min(pc_max, surplus, room))
             schedule[t, 0] = c
             soc[t + 1] = min(cap, soc[t] + c * eta)
-        elif net[t] > 1e-9:                                # importing
+        elif raw[t] > 1e-9:                                # importing
             avail = soc[t] * eta
-            cap_d = pd_max if battery.allows_export else net[t]
+            cap_d = pd_max if battery.allows_export else raw[t]
             d = max(0.0, min(pd_max, avail, cap_d))
             schedule[t, 1] = d
             soc[t + 1] = max(0.0, soc[t] - d / eta)
         else:
             soc[t + 1] = soc[t]
+    return schedule, soc
 
-    # ── Pass 2: per-day arbitrage on residual capacity ──────────────────
+
+def _pass2_arbitrage(df: pd.DataFrame, battery: Battery,
+                     schedule: np.ndarray, soc: np.ndarray) -> None:
+    """Per-UTC-day arbitrage layered on top of (schedule, soc). Mutates in place.
+
+    For each day, repeatedly find the most profitable (ci, di) pair where
+    profit = η·price[di] − price[ci]/η > 0 and both endpoints have power +
+    SoC headroom. Execute, update soc trajectory, repeat. Stops when no
+    profitable cycle remains.
+    """
+    cap = battery.capacity_kwh
+    pc_max = battery.max_charge_kw
+    pd_max = battery.max_discharge_kw
+    eta = battery.round_trip_eff ** 0.5
     if eta <= 0:
-        return schedule
+        return
     inv_eta = 1.0 / eta
 
-    # Index hours by UTC date (timeline is short enough that this is cheap).
+    raw = df["raw_demand_kw"].to_numpy()
+    prices = df["eur_per_kwh"].to_numpy()
+
     by_date: dict = {}
     for i, ts in enumerate(df.index):
         by_date.setdefault(ts.date(), []).append(i)
@@ -279,8 +242,6 @@ def oracle_daily_schedule(df: pd.DataFrame, battery: Battery) -> np.ndarray:
                 room_c = pc_max - schedule[ci, 0]
                 if room_c < 1e-9:
                     continue
-                # SoC headroom across (ci, end-of-day]: how much can we add
-                # to soc[ci+1..last+1] without exceeding cap?
                 tail = soc[ci + 1 : last + 2]
                 hr = (cap - tail.max()) / eta if tail.size else 0.0
                 if hr < 1e-9:
@@ -291,25 +252,16 @@ def oracle_daily_schedule(df: pd.DataFrame, battery: Battery) -> np.ndarray:
                     if room_d < 1e-9:
                         continue
                     if not battery.allows_export:
-                        # Discharge cannot exceed demand at di.
+                        # Plug-in: extra discharge limited by the post-Pass-1 import demand.
-                        room_d = min(room_d, net[di] - schedule[di, 1])
+                        room_d = min(room_d, raw[di] - schedule[di, 1])
                         if room_d < 1e-9:
                             continue
-                    # SoC must remain ≥ 0 across (ci, di]; new schedule has
-                    # +c at ci shifting trajectory up, then -d at di pulling
-                    # it down. Trajectory between ci+1..di stays elevated by
-                    # +x·η; minimum allowed kWh limited by min SoC in that
-                    # range plus future-discharge availability.
                     profit = eta * prices[di] - prices[ci] * inv_eta
                     if profit <= 1e-6:
                         continue
-
-                    # Max charge in AC kWh: limited by power, capacity headroom,
-                    # discharge-side capacity.
                     max_kwh = min(room_c, hr, room_d * inv_eta)
                     if max_kwh < 1e-6:
                         continue
-
                     if best is None or profit > best[2]:
                         best = (ci, di, profit, max_kwh)
             if best is None:
@@ -318,130 +270,20 @@ def oracle_daily_schedule(df: pd.DataFrame, battery: Battery) -> np.ndarray:
             ci, di, _, kwh = best
             schedule[ci, 0] += kwh
             schedule[di, 1] += kwh * eta
-            # Trajectory: SoC between ci+1 and di stays elevated by kwh*eta.
-            # SoC at di+1 onwards returns to original (+kwh*eta) - (kwh*eta) = unchanged).
             for t in range(ci, di):
                 soc[t + 1] += kwh * eta
-            # Beyond di, soc[di+1] = previous - d/eta = previous - kwh
+            # soc[di+1] onwards: +kwh*eta from charge cancels with -kwh*eta
-            # We added kwh*eta at soc[di], then removed kwh*eta on the
+            # from discharge → unchanged.
-            # discharge so soc[di+1] should already match — but we updated
-            # the loop with soc trajectory; need to ensure di+1 onward stays
-            # consistent.
-            # Easier: walk soc again from di onward to verify consistency.
-            # Since both sides cancel, soc[di+1..end] should be unchanged.
-
-    return schedule
-
-
-def _oracle_daily_schedule_legacy(df: pd.DataFrame, battery: Battery) -> np.ndarray:
-    """Legacy per-day LP (daily-myopic). Kept for reference / regression
-    testing only — the public oracle_daily_schedule() now solves the whole
-    window in one go to avoid SoC-resets-to-zero-overnight artefacts."""
-    cap = battery.capacity_kwh
-    pc_max = battery.max_charge_kw
-    pd_max = battery.max_discharge_kw
-    eta = battery.round_trip_eff ** 0.5
-
-    n = len(df)
-    schedule = np.zeros((n, 2))
-    soc = battery.initial_soc_kwh
-
-    # Position lookup so we can fill the global schedule from each day's solution.
-    pos = {ts: i for i, ts in enumerate(df.index)}
-
-    has_pv = "pv_kwh" in df.columns
-    has_export_price = "export_eur_per_kwh" in df.columns
-
-    for _, day_df in df.groupby(df.index.date, sort=True):
-        m = len(day_df)
-        import_price = day_df["eur_per_kwh"].to_numpy()
-        export_price = (
-            day_df["export_eur_per_kwh"].to_numpy() if has_export_price else import_price
-        )
-        demand = day_df["demand_kwh"].to_numpy()
-        pv = day_df["pv_kwh"].to_numpy() if has_pv else np.zeros(m)
-
-        # Variables: x = [c_0..c_{m-1}, d_0..d_{m-1}, gI_0..gI_{m-1}, gE_0..gE_{m-1}]
-        #   c   = charge from bus to battery (kWh AC)
-        #   d   = discharge from battery to bus (kWh AC)
-        #   gI  = grid import to bus (kWh, ≥ 0)
-        #   gE  = grid export from bus (kWh, ≥ 0)
-        # Energy balance per hour: gI - gE = demand - pv + c - d
-        #   → gI - gE - c + d = demand - pv
-        # Cost = sum(import_price * gI - export_price * gE).
-        # When import_price > export_price, the LP automatically picks
-        # min(gI, gE) = 0 because keeping both > 0 costs (imp - exp) > 0.
-        #
-        # Tiny tie-breakers: when several surplus hours are equally good for
-        # charging (true whenever export_price is constant and we're capturing
-        # surplus), the simplex would otherwise pick an arbitrary subset.
-        # Adding a microscopic penalty proportional to hour-index makes early
-        # charging strictly cheaper than late charging by a fraction of a
-        # cent — so the battery visibly fills as soon as surplus appears.
-        # Symmetric for discharge: prefer late hours (when prices are
-        # typically highest anyway, but ties happen during evening plateaus).
-        EPS = 1e-6
-        hr = np.arange(m)
-        f = np.concatenate([
-            EPS * hr,            # c: prefer earlier charging (smaller h ⇒ less cost)
-            EPS * (m - 1 - hr),  # d: prefer later discharging
-            import_price,        # pay for imports
-            -export_price,       # earn export credit
-        ])
-
-        # Variable bounds.
-        c_bounds = [(0.0, pc_max)] * m
-        if battery.allows_export:
-            d_bounds = [(0.0, pd_max)] * m
-        else:
-            # Plug-in: discharge ≤ net demand after solar (battery cannot push current backwards).
-            d_bounds = [
-                (0.0, min(pd_max, max(0.0, demand[t] - pv[t]))) for t in range(m)
-            ]
-        # Physical caps on grid flow per hour. Without these the LP can find
-        # zero-cost cycles when export_price ≈ 0 (charge from cheap surplus,
-        # discharge into cheap export — both sides zero, so any volume is "free").
-        # gI: practical max draw is demand + max charge; cap generously at 100 kWh/h.
-        # gE: bounded by *natural* export capacity = max(0, pv − demand). This
-        # also handles the case where the demand series is already net of an
-        # external PV (so demand can be negative even when pv = 0).
-        gi_bounds = [(0.0, 100.0)] * m
-        natural_export = np.maximum(0.0, pv - demand)
-        if battery.allows_export:
-            ge_bounds = [(0.0, max(1e-9, natural_export[t] + pd_max)) for t in range(m)]
-        else:
-            ge_bounds = [(0.0, max(1e-9, natural_export[t])) for t in range(m)]
-        bounds = c_bounds + d_bounds + gi_bounds + ge_bounds
-
-        # Energy balance equality (m rows): -c[t] + d[t] + gI[t] - gE[t] = demand[t] - pv[t]
-        I = np.eye(m)
-        A_eq = np.hstack([-I, I, I, -I])
-        b_eq = demand - pv
-
-        # SoC inequality (2m rows). SoC(t) = soc0 + eta*cumsum(c)[t] - cumsum(d)[t]/eta.
-        # Apply only to c, d columns; gI, gE are zero in these rows.
-        L = np.tril(np.ones((m, m)))
-        Z = np.zeros((m, m))
-        A_ub = np.vstack([
-            np.hstack([-eta * L,  (1.0 / eta) * L, Z, Z]),  # -SoC ≤ soc0  ⇒  SoC ≥ 0
-            np.hstack([ eta * L, -(1.0 / eta) * L, Z, Z]),  #  SoC ≤ cap - soc0 + soc0
-        ])
-        b_ub = np.concatenate([np.full(m, soc), np.full(m, cap - soc)])
-
-        result = linprog(
-            f, A_ub=A_ub, b_ub=b_ub, A_eq=A_eq, b_eq=b_eq, bounds=bounds, method="highs"
-        )
-        if not result.success:
-            raise RuntimeError(f"LP failed for {day_df.index[0].date()}: {result.message}")
-
-        c_day = result.x[:m]
-        d_day = result.x[m : 2 * m]
-
-        for t, ts in enumerate(day_df.index):
-            schedule[pos[ts], 0] = c_day[t]
-            schedule[pos[ts], 1] = d_day[t]
-
-        soc = soc + c_day.sum() * eta - d_day.sum() / eta
-        soc = max(0.0, min(cap, soc))
 
+
+def oracle_daily_schedule(df: pd.DataFrame, battery: Battery) -> np.ndarray:
+    """Greedy self-consumption (Pass 1) + perfect-foresight per-day arbitrage (Pass 2).
+
+    The ceiling for what a controller could achieve given a day-ahead price
+    series. Cross-day shifting is intentionally not allowed (the next day's
+    SoC starts wherever the previous day left it, but no within-day
+    arbitrage looks across the midnight boundary).
+    """
+    schedule, soc = _pass1_reactive(df, battery)
+    _pass2_arbitrage(df, battery, schedule, soc)
     return schedule

src/pluginbattery/static/app.js

@@ -56,8 +56,6 @@ function readScenario() {
   return {
     demand_kwh:  parseFloat(fd.get("demand_kwh")),
     retail:      parseFloat(fd.get("retail")),
-    pv_kwp:      parseFloat(fd.get("pv_kwp")),
-    pv_yield:    875.0,
     fixed_rate:  fd.get("fixed_rate") === "true",
     saldering:   fd.get("saldering")  === "true",
     eta:         parseFloat(fd.get("eta")),
@@ -267,7 +265,7 @@ const tlSummary = mustFind("tl-summary");
 
 let activeBattery = null;   // the row clicked
 let tlData = null;          // last fetched timeline payload
-let charts = { irr: null, soc: null, grid: null };
+let charts = { price: null, grid: null, soc: null };
 
 function openModalForBattery(row) {
   activeBattery = row;
@@ -292,7 +290,7 @@ function openModalForBattery(row) {
 function closeModal() {
   modal.hidden = true;
   for (const c of Object.values(charts)) c?.destroy?.();
-  charts = { irr: null, soc: null, grid: null };
+  charts = { price: null, grid: null, soc: null };
 }
 
 modal.querySelectorAll('[data-close="modal"]').forEach(
@@ -325,7 +323,7 @@ async function refreshTimeline() {
     start:         tlDate.value || "2024-06-17",
     days:          tlDays.value,
     demand_kwh:    sc.demand_kwh, retail: sc.retail,
-    pv_kwp:        sc.pv_kwp, fixed_rate: sc.fixed_rate,
+    fixed_rate:    sc.fixed_rate,
     saldering:     sc.saldering, eta: sc.eta,
   });
   if (sc.export_rate !== null) params.set("export_rate", sc.export_rate);
@@ -356,12 +354,12 @@ function paintTimeline(d) {
   tlSummary.replaceChildren();
   for (const [k, v] of [
     ["window cost",         `€${cost.toFixed(2)}`],
-    ["imports",             `${imports.toFixed(1)} kWh`],
+    ["imports",             `${imports.toFixed(2)} kWh`],
-    ["exports",             `${exports_.toFixed(1)} kWh`],
+    ["exports",             `${exports_.toFixed(2)} kWh`],
     ["battery throughput",  batteryOn
-        ? `${s.battery_charge_kwh.toFixed(1)} in / ${s.battery_discharge_kwh.toFixed(1)} out kWh`
+        ? `${s.battery_charge_kwh.toFixed(2)} in / ${s.battery_discharge_kwh.toFixed(2)} out kWh`
         : `— (battery off)`],
-    ["window saving",       `€${savings.toFixed(2)}`],
+    ["window saving",       `€${savings.toFixed(4)}`],
   ]) {
     const row = document.createElement("div");
     const lbl = document.createElement("span"); lbl.textContent = k;
@@ -371,18 +369,14 @@ function paintTimeline(d) {
 
   // X axis: unix seconds (uPlot wants epoch seconds)
   const xs    = d.hours.map(h => Date.parse(h.ts) / 1000);
-  const irr  = d.hours.map(h => h.irradiance);
+  const price = d.hours.map(h => h.price);
   const soc   = batteryOn ? d.hours.map(h => h.soc) : d.hours.map(() => 0);
   const grid  = batteryOn ? d.hours.map(h => h.grid_with_bat)
                           : d.hours.map(h => h.grid_no_bat);
 
-  drawChart("irr",  ["Time", "W/m²"], xs, irr, "tl-chart-irradiance", {
+  drawChart("price", ["Time", "€/kWh"], xs, price, "tl-chart-price", {
-    stroke: "#fbbf24", fill: "rgba(251, 191, 36, 0.2)",
+    stroke: "#a78bfa", fill: "rgba(167, 139, 250, 0.2)",
-    fmtY: (v) => v == null ? "" : `${v.toFixed(0)} W/m²`,
+    fmtY: (v) => v == null ? "" : `€${v.toFixed(3)}/kWh`,
-  });
-  drawChart("soc",  ["Time", "kWh"],  xs, soc, "tl-chart-soc", {
-    stroke: "#4ade80", fill: "rgba(74, 222, 128, 0.2)",
-    fmtY: (v) => v == null ? "" : `${v.toFixed(2)} kWh`,
   });
   drawChart("grid",  ["Time", "kWh/h"], xs, grid, "tl-chart-grid", {
     stroke: batteryOn ? "#93c5fd" : "#fb7185",
@@ -390,6 +384,10 @@ function paintTimeline(d) {
     zeroline: true,
     fmtY: (v) => v == null ? "" : `${v >= 0 ? "+" : ""}${v.toFixed(2)} kWh/h`,
   });
+  drawChart("soc",   ["Time", "kWh"],  xs, soc, "tl-chart-soc", {
+    stroke: "#4ade80", fill: "rgba(74, 222, 128, 0.2)",
+    fmtY: (v) => v == null ? "" : `${v.toFixed(2)} kWh`,
+  });
 }
 
 function drawChart(key, axes, xs, ys, containerId, opts = {}) {

src/pluginbattery/static/style.css

@@ -238,16 +238,25 @@ table#leaderboard tbody tr a { color: inherit; text-decoration: underline dotted
 }
 .modal-summary div { display: flex; justify-content: space-between; gap: 0.5rem; }
 .modal-summary div strong { color: var(--accent); }
+.modal-strategy {
+  border: 1px solid var(--border); border-radius: 8px; background: var(--panel2);
+  padding: 0.45rem 0.75rem 0.6rem; margin-bottom: 0.75rem;
+  display: flex; flex-wrap: wrap; gap: 0.25rem 1.25rem; align-items: center;
+}
+.modal-strategy legend { padding: 0 0.4rem; font-size: 0.78rem; color: var(--muted); }
+.modal-strategy .radio { display: inline-flex; align-items: center; gap: 0.4rem;
+                         font-size: 0.85rem; color: var(--text); cursor: pointer; }
+.modal-strategy .radio input { margin: 0; }
 .modal-charts { display: flex; flex-direction: column; gap: 0.6rem; }
 .modal-charts figure { margin: 0; background: var(--panel); border: 1px solid var(--border);
-                      border-radius: 8px; padding: 0.6rem 0.75rem 0.4rem; }
+                      border-radius: 8px; padding: 0.6rem 0.75rem 1rem; }
 .modal-charts figcaption { font-size: 0.78rem; color: var(--muted); margin-bottom: 0.3rem; }
-.modal-charts .chart { width: 100%; height: 110px; }
+.modal-charts .chart { width: 100%; height: 150px; }
-.modal-charts figure:nth-child(3) .chart { height: 200px; }   /* taller grid panel */
+.modal-charts figure:nth-child(4) .chart { height: 230px; }   /* taller grid panel (4th now) */
 
 /* uPlot dark-theme tweaks */
 .uplot { color: var(--text); }
-.uplot .u-legend { color: var(--text); font-size: 0.75rem; padding: 0.15rem 0; }
+.uplot .u-legend { color: var(--text); font-size: 0.75rem; padding: 1rem 0 0.6rem; }
 .uplot .u-legend th, .uplot .u-legend td { color: var(--text); padding: 0 0.4rem; }
 .uplot .u-legend .u-marker { display: inline-block; }
 .uplot .u-axis { color: var(--muted); }

src/pluginbattery/templates/index.html

@@ -5,7 +5,7 @@
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>Honest battery payback — vs thuisbatterijgids.nl</title>
 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/uplot@1.6.31/dist/uPlot.min.css">
-<link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}?v=20">
+<link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}?v=24">
 </head>
 <body>
 
@@ -22,21 +22,18 @@
   <aside id="inputs">
     <h2>Scenario</h2>
     <form id="scenario-form">
-      <label>Annual demand (kWh)
+      <label>Annual net draw at meter (kWh)
-        <input type="number" name="demand_kwh" min="500" max="20000" step="100" value="{{ defaults.demand_kwh }}">
+        <input type="number" name="demand_kwh" min="0" max="20000" step="1" value="{{ defaults.demand_kwh }}">
+        <small>Default 2325 kWh = dad's actual 2024 net (delivered 4301,
+        returned 1976). Increasing it adds a flat always-on load — more
+        imports, less surplus exported. The existing-PV export shape stays
+        untouched.</small>
       </label>
 
       <label>Average retail (€/kWh)
         <input type="number" name="retail" min="0.05" max="0.80" step="0.01" value="{{ defaults.retail }}">
       </label>
 
-      <label>PV system (kWp)
-        <input type="number" name="pv_kwp" min="0" max="100" step="any" value="{{ defaults.pv_kwp }}">
-        <small>0 = none (or already netted in your P1 data). Synthesizes
-        additional PV at 875 kWh/kWp/yr — leave at 0 unless you want to
-        model extra PV beyond what's in the load signal.</small>
-      </label>
-
       <fieldset>
         <legend>Tariff</legend>
         <label class="radio"><input type="radio" name="fixed_rate" value="false" checked> Dynamic (EPEX-based)</label>
@@ -87,7 +84,7 @@
     <div class="card">
       <h2>
         Full leaderboard
-        <small id="meta">(<span id="count">{{ initial.batteries|length }}</span> batteries · <span id="elapsed">{{ initial.elapsed_seconds }}</span>s · capturable surplus (= grid exports without a battery): <span id="total-surplus">{{ '%.0f' % initial.total_surplus_kwh }}</span> kWh/yr)</small>
+        <small id="meta">(<span id="count">{{ initial.batteries|length }}</span> batteries · <span id="elapsed">{{ initial.elapsed_seconds }}</span>s · existing PV exports at the meter (capturable by a battery): <span id="total-surplus">{{ '%.0f' % initial.total_surplus_kwh }}</span> kWh/yr)</small>
       </h2>
       <div class="filters">
         <label class="filter-toggle"><input type="checkbox" data-cat="small_plugin" checked> ≤ 0.8 kW plug-in (no electrician)</label>
@@ -106,10 +103,10 @@
             <th data-sort="lp_payback"          data-default-dir="asc"  title="Honest payback with inflation">LP yr</th>
             <th data-sort="ten_year_profit_eur" data-default-dir="desc" title="Cumulative savings over 10 yrs (with inflation) minus the battery cost">10-yr net</th>
             <th data-sort="cycles_per_year"            data-default-dir="desc" title="Total discharge throughput / capacity. Includes both surplus capture AND grid arbitrage.">cycles</th>
-            <th data-sort="captured_kwh"               data-default-dir="desc" title="kWh of solar surplus the battery actually absorbed (vs total surplus shown above)">kWh capt</th>
+            <th data-sort="captured_kwh"               data-default-dir="desc" title="kWh of meter-export (existing PV pushing back) the battery actually absorbed (vs total surplus shown above)">kWh capt</th>
-            <th data-sort="captured_pct"               data-default-dir="desc" title="Captured kWh as % of total available solar surplus">% capt</th>
+            <th data-sort="captured_pct"               data-default-dir="desc" title="Captured kWh as % of total existing-PV export at the meter">% capt</th>
-            <th data-sort="pct_hours_battery_full"     data-default-dir="desc" title="% of surplus hours where the battery was already full and couldn't store more">% full</th>
+            <th data-sort="pct_hours_battery_full"     data-default-dir="desc" title="% of export hours where the battery was already full and couldn't store more">% full</th>
-            <th data-sort="pct_hours_charge_saturated" data-default-dir="desc" title="% of surplus hours where charging was pegged at max kW and couldn't keep up">% sat</th>
+            <th data-sort="pct_hours_charge_saturated" data-default-dir="desc" title="% of export hours where the meter's surplus exceeded the battery's AC intake rate — the AC port physically can't absorb it all">% sat</th>
           </tr>
         </thead>
         <tbody id="leaderboard-body">{# rendered cells start below; legend follows the table. #}
@@ -138,10 +135,10 @@
         <dt>LP yr</dt>       <dd>Years until cumulative savings (with the chosen inflation rate) recoup the battery cost.</dd>
         <dt>10-yr net</dt>   <dd>Total profit over 10 years: cumulative savings (compounded by inflation) minus the battery cost. Red = doesn't break even within 10 yr.</dd>
         <dt>cycles</dt>      <dd>Total discharge throughput per year, divided by capacity. Includes <em>both</em> surplus capture and grid arbitrage (charging during cheap hours from the grid even when no surplus is exporting). Useful as a "how busy is the battery" metric.</dd>
-        <dt>kWh capt</dt>    <dd>kWh of capturable surplus (i.e. of grid exports that would happen without a battery) that this battery absorbs.</dd>
+        <dt>kWh capt</dt>    <dd>kWh of meter-export (existing PV pushing back) that this battery absorbs before it crosses the meter.</dd>
-        <dt>% capt</dt>      <dd>That, as a percentage of the scenario's capturable surplus shown in the heading. <em>Note:</em> the denominator is exports, not gross PV — solar that's directly self-consumed during sunny hours never crosses the meter and is invisible to a battery.</dd>
+        <dt>% capt</dt>      <dd>That, as a percentage of the scenario's existing-PV meter-export shown in the heading. <em>Note:</em> solar that's directly self-consumed during sunny hours never crosses the meter and is invisible to a battery.</dd>
-        <dt>% full</dt>      <dd>Of all surplus hours, the % when the battery was already full and couldn't store more — capacity-bottlenecked.</dd>
+        <dt>% full</dt>      <dd>Of all export hours, the % when the battery was already full and couldn't store more — capacity-bottlenecked.</dd>
-        <dt>% sat</dt>       <dd>Of all surplus hours, the % when charging was pegged at max kW and couldn't keep up — power-bottlenecked.</dd>
+        <dt>% sat</dt>       <dd>Of all export hours, the % when charging was pegged at max kW and couldn't keep up — power-bottlenecked.</dd>
       </dl>
     </div>
   </section>
@@ -149,10 +146,12 @@
 
 <footer>
   <p>
-    LP = 24h-foresight oracle (linear-program optimal dispatch) on 2023-09 → 2024-09 EPEX, P1, and irradiance.
+    LP = greedy self-consumption + perfect-foresight per-day price arbitrage, run over the recorded
-    Store calculator is reverse-engineered from observed quotes and matches them within €0.50.
+    EPEX + P1 net-meter trace. The simulator works on what the meter shows — solar already netted in,
-    The store's dynamic-rate quote treats charge cost as raw EPEX wholesale (no VAT, no energy tax), inflating
+    no separate PV synthesis. Store calculator is reverse-engineered from observed quotes and matches
-    arbitrage savings ~2× over what any real customer with a Dutch tariff actually pays.
+    them within €0.50. The store's dynamic-rate quote treats charge cost as raw EPEX wholesale
+    (no VAT, no energy tax), inflating arbitrage savings ~2× over what any real customer with a
+    Dutch tariff actually pays.
   </p>
 </footer>
 
@@ -171,6 +170,7 @@
         <option value="1">1 day</option>
         <option value="3">3 days</option>
         <option value="7" selected>7 days</option>
+        <option value="28">28 days</option>
       </select>
       <label class="filter-toggle"><input type="checkbox" id="tl-battery-on" checked> battery on</label>
       <span id="tl-status" class="status"></span>
@@ -178,22 +178,22 @@
     <div id="tl-summary" class="modal-summary"></div>
     <div class="modal-charts">
       <figure>
-        <figcaption>Solar irradiance — proxy for sun (W/m², from our weather station, season-aligned)</figcaption>
+        <figcaption>Consumer electricity price (€/kWh) — drives the arbitrage decisions</figcaption>
-        <div id="tl-chart-irradiance" class="chart"></div>
+        <div id="tl-chart-price" class="chart"></div>
+      </figure>
+      <figure>
+        <figcaption>Net meter (kWh/h). Positive = importing, negative = exporting.</figcaption>
+        <div id="tl-chart-grid" class="chart"></div>
       </figure>
       <figure>
         <figcaption>Battery state of charge (kWh)</figcaption>
         <div id="tl-chart-soc" class="chart"></div>
       </figure>
-      <figure>
-        <figcaption>Net meter flow (kWh per hour). Positive = importing, negative = exporting.</figcaption>
-        <div id="tl-chart-grid" class="chart"></div>
-      </figure>
     </div>
   </div>
 </div>
 
 <script src="https://cdn.jsdelivr.net/npm/uplot@1.6.31/dist/uPlot.iife.min.js"></script>
-<script src="{{ url_for('static', filename='app.js') }}?v=20"></script>
+<script src="{{ url_for('static', filename='app.js') }}?v=24"></script>
 </body>
 </html>

src/pluginbattery/web.py

@@ -4,6 +4,12 @@ Single page: inputs on the left, top recommendation + ranked catalog on the
 right. POST /api/calculate accepts a scenario JSON and returns a sorted list
 of every battery scored against both our LP and the cracked store formula.
 
+The simulator works on the raw P1 net-meter signal (``raw_demand_kw``,
+signed). Whatever the meter shows is the input — solar already netted in,
+no separate PV simulation. To model a different PV system you'd need an
+actual measurement of that system; reconstructing one from a remote
+irradiance sensor was tried and didn't survive contact with reality.
+
 Run locally:
     uv run flask --app pluginbattery.web run --debug --port 8000
 
@@ -28,7 +34,6 @@ from pluginbattery.sim import (
     load_hourly,
     oracle_daily_schedule,
     simulate,
-    synthesize_pv,
 )
 from pluginbattery.store_calc import (
     Scenario,
@@ -43,7 +48,17 @@ DATA_DIR = Path(__file__).resolve().parents[2] / "data" / "raw"
 
 print("Loading historical data…", flush=True)
 _BASE_DF = apply_nl_tariff(load_hourly(DATA_DIR))
-_ANNUAL_DEMAND_BASE = float(_BASE_DF["demand_kwh"].sum() * 8766.0 / len(_BASE_DF))
+# Linear extrapolation of what the recorded window says the annual net
+# draw would be. Used as the reference the form's additive demand slider
+# is measured against — so a slider value of `_ANNUAL_NET_DEMAND_BASE`
+# means "use the data unmodified".
+_ANNUAL_NET_DEMAND_BASE = float(_BASE_DF["raw_demand_kw"].sum() * 8766.0 / len(_BASE_DF))
+# Dad's actual recorded annual net for the most recent full calendar
+# year (his quote: "vorig jaar geleverd 4301 kWh, terug geleverd 1976
+# kWh, resteerde 2325 kWh"). Used as the default form value because our
+# data window is partial (~8 months, summer-heavy) and undershoots the
+# real annual figure.
+_REAL_ANNUAL_NET_DEMAND = 2325.0
 _AVG_CONSUMER_BASE = float(_BASE_DF["eur_per_kwh"].mean())
 
 with open(DATA_DIR / "thuisbatterijgids_catalog.json") as _f:
@@ -65,12 +80,7 @@ def _category(power_kw: float, allows_export: bool) -> str:
 
 
 def _lifetime_profit(year1: float, cost: float, years: int, inflation: float) -> float:
-    """Cumulative savings over `years` minus the up-front battery cost.
+    """Cumulative savings over `years` minus the up-front battery cost."""
-
-    Each successive year's savings are inflated by `inflation` (matches the
-    payback formula). Negative result = the battery doesn't break even
-    within the horizon.
-    """
     if inflation == 0:
         return year1 * years - cost
     return year1 * ((1 + inflation) ** years - 1) / inflation - cost
@@ -104,10 +114,11 @@ def _worker_run_lp(spec):
     )
     out = simulate(_WORKER_DF, bat, oracle_daily_schedule(_WORKER_DF, bat))
 
-    demand = _WORKER_DF["demand_kwh"].to_numpy()
+    # "Surplus" = hours where the meter was already exporting before any
-    pv = (_WORKER_DF["pv_kwh"].to_numpy()
+    # battery action, i.e. existing PV pushing back. The battery's job on
-          if "pv_kwh" in _WORKER_DF.columns else np.zeros(len(_WORKER_DF)))
+    # those hours is to absorb that flow before it crosses the meter.
-    surplus = np.maximum(0.0, pv - demand)
+    raw = _WORKER_DF["raw_demand_kw"].to_numpy()
+    surplus = np.maximum(0.0, -raw)
     surplus_mask = surplus > 1e-6
     n_surplus_hours = int(surplus_mask.sum())
 
@@ -117,9 +128,12 @@ def _worker_run_lp(spec):
 
     if n_surplus_hours > 0:
         soc = out["soc_kwh"].to_numpy()
-        charge = out["charge_kwh"].to_numpy()
         pct_full = float((surplus_mask & (soc >= cap - 1e-3)).sum()) / n_surplus_hours * 100.0
-        pct_saturated = float((surplus_mask & (charge >= pw - 1e-3)).sum()) / n_surplus_hours * 100.0
+        # Power bottleneck: the meter is exporting *more* than the battery's
+        # AC port can absorb in a single hour. This is purely a function of
+        # surplus vs pc_max — it does not get confounded by Pass-2 arbitrage
+        # topping the battery off from the grid during cheap export hours.
+        pct_saturated = float((surplus >= pw - 1e-3).sum()) / n_surplus_hours * 100.0
     else:
         pct_full = 0.0
         pct_saturated = 0.0
@@ -135,18 +149,24 @@ def _worker_run_lp(spec):
 
 
 # ─── Core compute ─────────────────────────────────────────────────────
-def _build_df(demand_kwh: float, retail: float, pv_kwp: float, pv_yield: float,
+def _build_df(demand_kwh: float, retail: float,
               fixed_rate: bool, saldering: bool, export_rate: float | None):
     df = _BASE_DF.copy()
-    df["demand_kwh"] = _BASE_DF["demand_kwh"] * (demand_kwh / _ANNUAL_DEMAND_BASE)
+    # Apply the demand slider as an *additive* shift, not a multiplicative
+    # one. The signal is `gross_demand − PV` and we can't separate them,
+    # but we can model "this same house plus a constant always-on load"
+    # by adding a flat kW baseline. That leaves the PV-export shape
+    # untouched (a 3 kWp system still produces what it produces), and
+    # lifts the imports + reduces the surplus by the same amount —
+    # exactly what an extra fixed load would do.
+    delta_kw = (demand_kwh - _ANNUAL_NET_DEMAND_BASE) / 8766.0
+    df["raw_demand_kw"] = _BASE_DF["raw_demand_kw"] + delta_kw
     if fixed_rate:
         df["eur_per_kwh"] = float(retail)
     else:
         scale = retail / _AVG_CONSUMER_BASE
         df["eur_per_kwh"] = _BASE_DF["eur_per_kwh"] * scale
         df["epex_eur_per_kwh"] = _BASE_DF["epex_eur_per_kwh"] * scale
-    if pv_kwp > 0:
-        df = synthesize_pv(df, kwp=pv_kwp, target_kwh_per_kwp_per_year=pv_yield)
     if export_rate is not None:
         df["export_eur_per_kwh"] = float(export_rate)
     elif saldering:
@@ -160,41 +180,34 @@ def compute_leaderboard(
     *,
     demand_kwh: float,
     retail: float,
-    pv_kwp: float,
-    pv_yield: float,
     fixed_rate: bool,
     saldering: bool,
     eta: float,
     inflation: float,
     export_rate: float | None = None,
 ) -> dict:
-    key = (round(demand_kwh, 1), round(retail, 4), round(pv_kwp, 2),
+    key = (round(demand_kwh, 1), round(retail, 4),
-           round(pv_yield, 1), fixed_rate, saldering, round(eta, 3),
+           fixed_rate, saldering, round(eta, 3),
            round(inflation, 4),
            None if export_rate is None else round(export_rate, 4))
     if key in _RESULT_CACHE:
         return _RESULT_CACHE[key]
 
     t0 = time.time()
-    df = _build_df(demand_kwh, retail, pv_kwp, pv_yield, fixed_rate, saldering, export_rate)
+    df = _build_df(demand_kwh, retail, fixed_rate, saldering, export_rate)
     avg_epex = float(df["epex_eur_per_kwh"].mean())
     store_params = StoreParams(avg_epex_eur_per_kwh=avg_epex)
 
-    # Annualisation factor: our data window may be shorter than a year (e.g.,
+    # Annualisation factor: our data window may be shorter than a year.
-    # 8 months when solar coverage limits the overlap). Scale all per-window
+    # Scale all per-window extensive quantities so they represent a full year.
-    # extensive quantities (savings, kWh shifted, captured, surplus) so they
-    # represent a full year. Intensive metrics like % full / % saturated stay
-    # as-is.
     annualize = 8766.0 / len(df)
 
-    # Total PV / surplus available across the whole scenario (no battery).
+    # Existing-PV surplus visible at the meter across the whole window
-    pv_col = df["pv_kwh"].to_numpy() if "pv_kwh" in df.columns else np.zeros(len(df))
+    # (hours where raw_demand_kw < 0, i.e. dad's PV exporting).
-    window_surplus = float(np.maximum(0.0, pv_col - df["demand_kwh"].to_numpy()).sum())
+    raw = df["raw_demand_kw"].to_numpy()
+    window_surplus = float(np.maximum(0.0, -raw).sum())
     total_surplus_kwh = window_surplus * annualize
 
-    # Collect every distinct (capacity, power) the catalog asks for, then run
-    # the per-spec LPs in parallel. linprog/HiGHS release the GIL so threads
-    # give a near-linear speedup on this VM (4 cores).
     valid_rows = []
     specs: set[tuple[float, float, bool]] = set()
     for b in _CATALOG:
@@ -210,26 +223,21 @@ def compute_leaderboard(
         valid_rows.append((b, cap, pw, price, allows_export))
         specs.add((round(cap, 3), round(pw, 3), allows_export))
 
-    # Cache key for "what does this LP depend on?" — everything that goes
+    df_sig = (round(demand_kwh, 1), round(retail, 4),
-    # into the dataframe construction plus eta. Inflation isn't in here, so
+              fixed_rate, saldering, round(eta, 3),
-    # tweaking only inflation hits the cache for every catalog entry.
-    df_sig = (round(demand_kwh, 1), round(retail, 4), round(pv_kwp, 2),
-              round(pv_yield, 1), fixed_rate, saldering, round(eta, 3),
               None if export_rate is None else round(export_rate, 4))
 
     cached_results = {}
     todo = []
     for spec in specs:
-        key = (df_sig, *spec)
+        cache_key = (df_sig, *spec)
-        if key in _LP_CACHE:
+        if cache_key in _LP_CACHE:
-            cached_results[spec] = _LP_CACHE[key]
+            cached_results[spec] = _LP_CACHE[cache_key]
         else:
             todo.append(spec)
 
     if todo:
         workers = min(len(todo), int(os.environ.get("PLUGINBATTERY_LP_WORKERS", "4")))
-        # Fork pool: each worker inherits `df` via copy-on-write rather than
-        # pickling it on every task — fast cold scenarios.
         ctx = get_context("fork")
         with ProcessPoolExecutor(
             max_workers=max(1, workers),
@@ -248,8 +256,8 @@ def compute_leaderboard(
         payload = lp_cache[(round(cap, 3), round(pw, 3), allows_export)]
         lp_year1 = payload["year1"] * annualize
         captured_kwh = payload["captured_kwh"] * annualize
-        pct_full = payload["pct_full"]                       # already a ratio
+        pct_full = payload["pct_full"]
-        pct_saturated = payload["pct_saturated"]             # already a ratio
+        pct_saturated = payload["pct_saturated"]
         discharge_kwh = payload["discharge_kwh"] * annualize
         cycles_per_year = discharge_kwh / cap if cap > 0 else 0.0
         captured_pct = (captured_kwh / total_surplus_kwh * 100.0) if total_surplus_kwh > 0 else 0.0
@@ -265,7 +273,7 @@ def compute_leaderboard(
             scn = Scenario(
                 capacity_kwh=cap, max_charge_kw=pw, battery_cost_eur=price,
                 avg_retail_eur_per_kwh=retail,
-                has_pv=pv_kwp > 0, has_saldering=saldering,
+                has_pv=total_surplus_kwh > 0, has_saldering=saldering,
                 dynamic_rate=not fixed_rate,
             )
             sq = store_quote(scn, store_params, inflation=inflation)
@@ -301,7 +309,6 @@ def compute_leaderboard(
     result = {
         "scenario": {
             "demand_kwh": demand_kwh, "retail": retail,
-            "pv_kwp": pv_kwp, "pv_yield": pv_yield,
             "fixed_rate": fixed_rate, "saldering": saldering,
             "eta": eta, "inflation": inflation,
             "export_rate": export_rate,
@@ -321,15 +328,14 @@ def compute_leaderboard(
 app = Flask(__name__)
 
 DEFAULTS = dict(
-    # Window: 2025-01-01 → 2025-09-01 (8 months of dad's actual data with
+    # Demand default = dad's real full-year annual net (2325 kWh per his
-    # matching 2025 prices + solar). The simulator scales demand by
+    # quote). Larger than what the partial-window data extrapolates to
-    # demand_kwh / ANNUAL_DEMAND_BASE; ANNUAL_DEMAND_BASE annualises the
+    # (~1515 kWh) because we're missing the winter months; the slider's
-    # 8-month window's 1010 kWh → 1518 kWh-equivalent/yr, so set the
+    # additive shift compensates.
-    # default to 1518 to keep the per-hour P1 values unscaled (scale = 1.0).
+    # export_rate = 0 by default. Dad's actual situation has
-    # export_rate = 0 by default to keep the model simple. Dad's actual
+    # terugleveringskosten of −€0.106/kWh; set the field explicitly to
-    # situation has terugleveringskosten of −€0.106/kWh; set the field
+    # that value when modelling his real bill.
-    # explicitly to that value when modelling his real bill.
+    demand_kwh=round(_REAL_ANNUAL_NET_DEMAND), retail=0.25,
-    demand_kwh=1518.0, retail=0.25, pv_kwp=0.0, pv_yield=875.0,
     fixed_rate=False, saldering=False, eta=0.88, inflation=0.03,
     export_rate=0.0,
 )
@@ -338,7 +344,13 @@ DEFAULTS = dict(
 @app.route("/")
 def index():
     initial = compute_leaderboard(**DEFAULTS)
-    return render_template("index.html", initial=initial, defaults=DEFAULTS)
+    resp = app.make_response(render_template("index.html", initial=initial, defaults=DEFAULTS))
+    # Cache-bust query strings on app.js/style.css only help if the browser
+    # re-fetches index.html — force a fresh page on every request.
+    resp.headers["Cache-Control"] = "no-store, no-cache, must-revalidate, max-age=0"
+    resp.headers["Pragma"] = "no-cache"
+    resp.headers["Expires"] = "0"
+    return resp
 
 
 @app.route("/api/calculate", methods=["POST"])
@@ -356,8 +368,6 @@ def calculate():
         result = compute_leaderboard(
             demand_kwh=float(p.get("demand_kwh", DEFAULTS["demand_kwh"])),
             retail=float(p.get("retail", DEFAULTS["retail"])),
-            pv_kwp=float(p.get("pv_kwp", DEFAULTS["pv_kwp"])),
-            pv_yield=float(p.get("pv_yield", DEFAULTS["pv_yield"])),
             fixed_rate=bool(p.get("fixed_rate", DEFAULTS["fixed_rate"])),
             saldering=bool(p.get("saldering", DEFAULTS["saldering"])),
             eta=float(p.get("eta", DEFAULTS["eta"])),
@@ -371,12 +381,7 @@ def calculate():
 
 @app.route("/api/timeline")
 def timeline():
-    """Per-hour LP trajectory for a battery over a chosen window.
+    """Per-hour trajectory for a battery over a chosen window."""
-
-    Returns both 'with battery' and 'without battery' series so the UI can
-    toggle between them without round-tripping. Defaults to a sunny mid-June
-    week.
-    """
     q = request.args
     try:
         cap = float(q.get("cap", "1.92"))
@@ -387,16 +392,11 @@ def timeline():
 
         demand_kwh = float(q.get("demand_kwh", DEFAULTS["demand_kwh"]))
         retail = float(q.get("retail", DEFAULTS["retail"]))
-        pv_kwp = float(q.get("pv_kwp", DEFAULTS["pv_kwp"]))
-        pv_yield = float(q.get("pv_yield", DEFAULTS["pv_yield"]))
         fixed_rate = q.get("fixed_rate", "false").lower() == "true"
         saldering = q.get("saldering", "false").lower() == "true"
         eta = float(q.get("eta", DEFAULTS["eta"]))
         raw_export = q.get("export_rate")
         if raw_export is None:
-            # Param absent → use the configured default (matches the form's
-            # initial value). 'export_rate=' (explicit empty) still means
-            # 'fall back to saldering toggle'.
             export_rate = DEFAULTS.get("export_rate")
         elif raw_export in ("", "null"):
             export_rate = None
@@ -405,7 +405,7 @@ def timeline():
     except (TypeError, ValueError) as e:
         return jsonify({"error": f"bad query param: {e}"}), 400
 
-    df = _build_df(demand_kwh, retail, pv_kwp, pv_yield, fixed_rate, saldering, export_rate)
+    df = _build_df(demand_kwh, retail, fixed_rate, saldering, export_rate)
     bat = Battery(
         capacity_kwh=cap, max_charge_kw=power, max_discharge_kw=power,
         round_trip_eff=eta, allows_export=allows_export,
@@ -420,7 +420,7 @@ def timeline():
         return jsonify({"error": f"no data for {start_raw} + {days} days "
                                   f"(window: {out.index[0].date()}..{out.index[-1].date()})"}), 400
 
-    g_no = (win["demand_kwh"] - win.get("pv_kwh", 0)).to_numpy()
+    g_no = win["raw_demand_kw"].to_numpy()
     g_yes = win["grid_kwh_with_battery"].to_numpy()
     imp_p = win["eur_per_kwh"].to_numpy()
     exp_p = win.get("export_eur_per_kwh", win["eur_per_kwh"]).to_numpy()
@@ -431,9 +431,9 @@ def timeline():
     for i, (ts, r) in enumerate(win.iterrows()):
         hours_payload.append({
             "ts":            ts.isoformat(),
-            "irradiance":    float(r.get("irradiance_w_m2", 0.0)),
             "price":         float(r["eur_per_kwh"]),
             "export_price":  float(r.get("export_eur_per_kwh", r["eur_per_kwh"])),
+            "raw_demand":    float(r["raw_demand_kw"]),
             "soc":           float(r["soc_kwh"]),
             "charge":        float(r["charge_kwh"]),
             "discharge":     float(r["discharge_kwh"]),
@@ -447,7 +447,7 @@ def timeline():
         "battery":        {"capacity_kwh": cap, "power_kw": power,
                             "allows_export": allows_export},
         "scenario":       {"demand_kwh": demand_kwh, "retail": retail,
-                            "pv_kwp": pv_kwp, "saldering": saldering,
+                            "saldering": saldering,
                             "fixed_rate": fixed_rate, "eta": eta,
                             "export_rate": export_rate},
         "window":         {"start": start_ts.isoformat(), "days": days,

tests/test_sim.py

@@ -10,18 +10,21 @@ from pluginbattery.sim import (
     apply_nl_tariff,
     oracle_daily_schedule,
     simulate,
-    synthesize_pv,
 )
 
 
-def make_df(prices: list[float], demands_kwh: list[float]) -> pd.DataFrame:
+def make_df(prices: list[float], raw_demands_kw: list[float]) -> pd.DataFrame:
+    """Build an hourly fixture DataFrame.
+
+    raw_demands_kw is signed: positive = importing, negative = exporting
+    (existing PV pushing back through the meter).
+    """
     idx = pd.date_range("2024-01-01", periods=len(prices), freq="h", tz="UTC")
     return pd.DataFrame(
         {
             "eur_per_kwh": prices,
-            "power_w": np.array(demands_kwh) * 1000.0,
+            "power_w": np.array(raw_demands_kw) * 1000.0,
-            "irradiance_w_m2": 0.0,
+            "raw_demand_kw": raw_demands_kw,
-            "demand_kwh": demands_kwh,
         },
         index=idx,
     )
@@ -43,12 +46,12 @@ def test_plugin_never_exports():
                   round_trip_eff=1.0, allows_export=False, initial_soc_kwh=2.0)
     schedule = np.array([[0.0, 0.8]] * 3)  # try to dump at full power
     out = simulate(df, bat, schedule)
-    assert (out["discharge_kwh"] <= out["demand_kwh"] + 1e-9).all()
+    assert (out["discharge_kwh"] <= out["raw_demand_kw"] + 1e-9).all()
     assert (out["grid_kwh_with_battery"] >= -1e-9).all()
 
 
 def test_grid_arbitrage_kicks_in_on_no_sun_days():
-    """Without PV but with a daily price spread, the dispatcher should
+    """Without surplus but with a daily price spread, the dispatcher should
     charge during the cheapest hours and discharge during the most
     expensive — same dynamic-tariff behaviour Tibber-style controllers do."""
     prices = [0.05] * 12 + [0.50] * 12
@@ -66,23 +69,23 @@ def test_grid_arbitrage_kicks_in_on_no_sun_days():
     assert out["savings"].sum() > 0
 
 
-def test_greedy_fills_from_surplus_then_overflows():
+def test_greedy_fills_from_meter_export_then_overflows():
-    """With PV surplus, greedy fills the battery as fast as power allows
+    """When the meter is already exporting (existing PV pushing back),
-    until capacity is reached, then lets the rest export."""
+    greedy fills the battery as fast as power allows until capacity is
+    reached, then lets the rest flow out the meter."""
     prices = [0.20] * 24
-    demand = [0.1] * 24
+    # 6 hours of net-export (−3 kW each), then 12 hours of import demand.
-    pv = [0.0] * 6 + [3.0] * 6 + [0.0] * 12   # 6 sunny hours, 3 kWh/h surplus
+    raw = [0.1] * 6 + [-3.0] * 6 + [0.1] * 12
-    df = make_df(prices, demand)
+    df = make_df(prices, raw)
-    df["pv_kwh"] = pv
     bat = Battery(capacity_kwh=2.0, max_charge_kw=0.8, max_discharge_kw=0.8,
                   round_trip_eff=1.0, allows_export=False)
     schedule = oracle_daily_schedule(df, bat)
     out = simulate(df, bat, schedule)
-    # Charging happens during the first surplus hours, capped at 0.8 kW
+    # Charging happens during the first export hours, capped at 0.8 kW
     assert out["charge_kwh"].iloc[6:9].sum() == pytest.approx(2.0, abs=1e-6)
-    # Once full, no more charging even though surplus continues
+    # Once full, no more charging even though export continues
     assert out["charge_kwh"].iloc[9:12].sum() == 0
-    # Battery discharges into evening demand
+    # Battery discharges into evening import demand
     assert out["discharge_kwh"].iloc[12:].sum() > 0
 
 
@@ -119,55 +122,40 @@ def test_oracle_skips_arbitrage_when_eff_kills_it():
     assert out["savings"].sum() < 1e-6
 
 
-def test_synthesize_pv_hits_target_annual():
+def test_plugin_never_pushes_to_grid_during_export_hours():
-    """synthesize_pv should calibrate so annual output ≈ target × kWp."""
+    """Plug-in battery during meter-export hours: discharge must be 0
-    n = 24 * 30  # 30 days
+    (battery cannot push current backwards, and the meter is already
-    idx = pd.date_range("2024-06-01", periods=n, freq="h", tz="UTC")
+    flowing the wrong way)."""
-    # Simple square wave: 600 W/m² for 8 daylight hours, zero otherwise.
+    prices = [0.30] * 24
-    irr = np.zeros(n)
+    # First 12 hours: meter is exporting (-3 kWh/h). Last 12: importing (+0.5 kWh/h).
-    for d in range(30):
+    raw = [-3.0] * 12 + [0.5] * 12
-        irr[d * 24 + 8 : d * 24 + 16] = 600.0
+    df = make_df(prices, raw)
-    df = pd.DataFrame({
-        "eur_per_kwh": 0.20, "power_w": 0.0,
-        "irradiance_w_m2": irr, "demand_kwh": 0.0,
-    }, index=idx)
-    out = synthesize_pv(df, kwp=3.0, target_kwh_per_kwp_per_year=900.0)
-    annual_pv = out["pv_kwh"].sum() * (8766 / n)
-    assert abs(annual_pv - 3.0 * 900.0) < 1.0
-
-
-def test_plugin_with_pv_does_not_push_to_grid():
-    """Plug-in battery + surplus solar: discharge must be 0 in surplus hours."""
-    df = make_df([0.30] * 24, [0.5] * 24)
-    df["pv_kwh"] = [3.0] * 12 + [0.0] * 12  # huge midday surplus
     bat = Battery(capacity_kwh=2.0, max_charge_kw=0.8, max_discharge_kw=0.8,
                   round_trip_eff=0.9, allows_export=False, initial_soc_kwh=2.0)
     schedule = np.array([[0.0, 0.8]] * 24)  # try to dump every hour
     out = simulate(df, bat, schedule)
-    surplus_hours = out["pv_kwh"] > out["demand_kwh"]
+    export_hours = out["raw_demand_kw"] < 0
-    assert (out.loc[surplus_hours, "discharge_kwh"] == 0).all()
+    assert (out.loc[export_hours, "discharge_kwh"] == 0).all()
 
 
 def test_no_saldering_increases_battery_savings():
-    """Removing saldering should make a battery on a PV system more valuable.
+    """Removing saldering should make a battery on a house-with-PV more valuable.
 
-    Reason: surplus solar that previously credited at consumer price now only
+    Reason: meter-export that previously credited at consumer price now only
     earns raw EPEX. Storing it for later self-consumption is now strictly
     better than the previous opportunity cost.
     """
-    # Day with cheap morning EPEX, noon surplus solar, expensive evening.
+    # Day with cheap morning EPEX, midday meter-export (existing PV), expensive evening.
     prices_consumer = [0.20] * 6 + [0.15] * 6 + [0.40] * 12
     prices_epex     = [0.05] * 6 + [0.02] * 6 + [0.20] * 12  # before VAT/tax
-    demands         = [0.5] * 24
+    # Net: small import morning, big export midday (PV peak), evening import.
-    pv              = [0.0] * 8 + [3.0] * 6 + [0.0] * 10
+    raw             = [0.5] * 8 + [-3.0] * 6 + [0.5] * 10
     n = 24
     idx = pd.date_range("2024-01-01", periods=n, freq="h", tz="UTC")
     base = pd.DataFrame({
         "eur_per_kwh": prices_consumer,
-        "power_w": np.array(demands) * 1000.0,
+        "power_w": np.array(raw) * 1000.0,
-        "irradiance_w_m2": 0.0,
+        "raw_demand_kw": raw,
-        "demand_kwh": demands,
-        "pv_kwh": pv,
         "epex_eur_per_kwh": prices_epex,
     }, index=idx)
     bat = Battery(capacity_kwh=5.0, max_charge_kw=2.5, max_discharge_kw=2.5,